# Advice on Bridgeport converted to CNC for sale



## Charlieman22

Gents,
Newcomer tying to get up to speed on CNC BP or BP clone conversions.
Went to look at a Bridgeport today - not yet listed for sale.
Surprised to find it was converted to CNC already.

He is the original owner.  
Showed me the receipt from 1973(ish) for $6500 all in including vice.
It's a job shop and he is retiring.
Very little use now.

Set up uses a 486 computer (that is not a typo) and an ancient cable (R something) from the computer to the machine.
The computer is on last legs - perhaps a better description might be last knees at this point.
He ran what ever program was last used.  X/Y/&Z axis all hummed and spun and it moved back to .005 of the zeroed out origin point (to my surprise!), at least once.
Pics of the conversion below.

Questions:
 - If I want CNC - would it be a better value to just convert a machine with new system myself? 
 - Is there a scenario worth considering where perhaps some but not all of the components on this machine should be replaced/upgraded? Why the 486 computer?
 - On a newer clone, that has powered x/y/z axis - is that feed system good enough to convert to CNC - or do you need to put new CNC specific servos on to operate properly?

Few pics below of the Bridgeport.  The last image is of a clone I'm looking at that has all three axis powered.
Thanks for taking the time to read.
Anything that could help get me educated much appreciated.
-CM


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## projectnut

I can't speak for this particular machine, but it is of the same vintage as the Bridgeport I purchased many years ago.  Mine has a 1 1/2 hp spindle motor with the variable speed drive.  It had the same power feed on the table and came from the factory with a set of collets by 1/16" and a vise.

Mine came from a local high school and looked to be in about the same condition.  When I disassembled it to move it to the shop I found the original paperwork in the column.  The school had paid a little over $1,400.00 for the machine and the accessories.  The price of $6,500.00 seems a bit excessive when a more expensive base machine only cost $1,400.00 from the factory.  

I would guess the conversion was made many years later, possibly around the early to mid 1980's.  That's the era of the 486 computers.  By the mid 1990's things changed to the early Pentium platform.


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## wrat

projectnut said:


> I would guess the conversion was made many years later, possibly around the early to mid 1980's.  That's the era of the 486 computers.  By the mid 1990's things changed to the early Pentium platform.


I believe you're off by about a decade.
In the mid 80s (1985) a 386 rig was a $13,000 computer.  The 486 was touted, when found, by the early-90s.  Heh, heh... those were the tragic days - if you brought a  computer home, it went obsolete as you unboxed it.
Regardless the ancient chipset, I'd be leery of a BP that's already converted by a working shop.  These things are often beat TO DEATH by their own NC drivers without their owners knowing it; often without deceleration blocks in the coding but snapped corner to corner.  And then being left to run day-in and day-out.  
Remember, the whole idea of NC is to make the machine move longer, faster, and more often than a hand crank can do it.
So it's possible - not always the case, natch - but possible this thing has had 20 years of cranking for every year of NC service.
[yes, yes, i know there's always that one guy that never heard of such a thing....]

The wear is where you don't see it:  in the ways and bearings.  Pernicious wear in the form of bowing and not scoring.
It might "run just fine" but if they're making parts that have to be good to .030 and you're wanting to do setup and make cuts to .005 or less then caveat emptor.

Now with all that doom and gloom out of the way, this thing might be a heck of a find.  Cast aluminum pulley housings?  That's great!  Still runs?  That's very cool.  I'd buy it for the right price.

Another point, if this is a 486-based system, this hearkens from an era where the actual programming was usually done elsewhere.  In the office.  Then the code was loaded into the machine at the computer (NC) as opposed to fully programmed in the shop at the machine (CNC).   It takes next to nothing computer-wise to simply move the machine to XYZ so for decades, these were just data buckets loaded from something else - everything from punch tape to a Cat5 cable (DNC).

Finally, "last legs" is often simply neglect.  These boards, yes, even a lowly 486, will run past your lifetime if care is taken up front.  The trouble is often one of hostile environment.  Oil and smoke vapor condense on the board that's not housed in a sealed cabinet producing random and frustrating errors.  A PC of that (or almost any) era is doomed if it's housed in a production shop environment - unless it's of a hardened type.

If the price was right (no more than maybe $3K) I wouldn't laugh.  At $2k,  I'd snap it up.  If he wants sticker price of $6.5K I'd walk.  Because just the 'conversion kit' for something like a Precision Matthews is about $1400 -- and that's after buying the mill at around $4K (plus of minus loads of extras).  That's around $6K for entry level, but a brand new, precise machine.

But I'm not in Los Angeles and the market here is pretty spotty.


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## Charlieman22

projectnut said:


> The school had paid a little over $1,400.00 for the machine and the accessories.  The price of $6,500.00 seems a bit excessive when a more expensive base machine only cost $1,400.00 from the factory.


They do sound similar.  Not sure why it would be such a discrepancy.  I think there was no more than $2K of additional items, tax, delivery...  



wrat said:


> Regardless the ancient chipset, I'd be leery of a BP that's already converted by a working shop.  These things are often beat TO DEATH by their own NC drivers without their owners knowing it; often without deceleration blocks in the coding but snapped corner to corner.  And then being left to run day-in and day-out.


This is precisely my concern.  


wrat said:


> Another point, if this is a 486-based system, this hearkens from an era where the actual programming was usually done elsewhere. In the office. Then the code was loaded into the machine at the computer (NC) as opposed to fully programmed in the shop at the machine (CNC).


This is the case.


wrat said:


> Finally, "last legs" is often simply neglect. These boards, yes, even a lowly 486, will run past your lifetime if care is taken up front. The trouble is often one of hostile environment. Oil and smoke vapor condense on the board that's not housed in a sealed cabinet producing random and frustrating errors. A PC of that (or almost any) era is doomed if it's housed in a production shop environment - unless it's of a hardened type.


All the above.  I had to help him try to start it.  Managed to start it once before it froze and then no amount of un-powering would get it to do anything by make that beep sound from the board.  20 years of dust and grime.



wrat said:


> If the price was right (no more than maybe $3K) I wouldn't laugh. At $2k, I'd snap it up. If he wants sticker price of $6.5K I'd walk. Because just the 'conversion kit' for something like a Precision Matthews is about $1400 -- and that's after buying the mill at around $4K (plus of minus loads of extras). That's around $6K for entry level, but a brand new, precise machine.


He is asking $4500 - though there is room to negotiate.  But I have some trepidation about negotiating even to $3K or $3500 if its beaten to death from years of CNC.  Side note - someone on another thread I had posted on regarding moving of machines noted that the control box might be replaceable with an Acorn model control box- which would allow a windows 10PC.

Still trying to understand if the powered axis I see on modern clones (like the PM machine you note) are sufficient as drivers for CNC or if you need to use what appear to me to be larger motors like what I see on many of the CNC conversions?


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## markba633csi

Looks like it uses beefy DC servo motors- nice hardware but old.  Worn, for sure but for hobby use probably fine.  Personally I would only want to pay around 2500$ max
-Mark


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## Janderso

I saw one of those go for $400 at a Bidcal auction. Nobody knew what to do with it. It didn't have a DRO though.


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## macardoso

If it were me, and the price was right, and the machine was not too worn, and I could get it home, then I'd be replacing the controls.

The actual choice of control software (Mach 4, Centroid, Linux CNC, etc.) is of little relevance to me. What I would be concerned about is the DC servos. Those are big boys and will need interface to the old amplifiers (if functional and trusty) or new amplifiers to replace them. Older machines only had tachometers on the motors and glass scales on the axes. This is different from the digital encoders expected by most modern DC servo drive control systems. The motion control board must then be able to interface with whatever drive you want to use. If the drive is analog input then the motion controller is significantly more expensive than one for controlling pulse input drives. 

Alternatively you can replace the motors with modern AC servos, but I'd budget (at a minimum) $2000 to get motors, drives, and cables.

It can work, but expect to need to dive in head first, learn about the controls, and select replacements. There will be cost associated with this.

Personally, I search for these kind of projects because they are fun for me, others maybe not. You need to do your own soul searching to figure out if you want a project machine or a machine that works out of the box.


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## Charlieman22

Marcardoso - good run down.  Drinking water from fire hydrant on this one - but that's a norm for me when jumping into something new.  Goal is to not get my lips ripped off.

My understanding of the components is rudimentary - but your explanation is helpful.  Sorta like not being able to use a modern Amp with an old phonograph.  


macardoso said:


> It can work, but expect to need to dive in head first, learn about the controls, and select replacements. There will be cost associated with this.


For sure I need to determine this.

Two questions: 
1.  Assuming DC motors are good (they seam to be) and their respective amplifiers are as well - what would your approach be for setup? (and are these amplifiers inside the large black box?). That is - what would you buy/swap out hardware wise (I assume it would solve for a digital rather than analog input?)
2.  Are the modern servos like what I showed in last pic of my first post capable/suitable/desirable for changing to CNC or would I want to upgrade those as well, if I went with the modern clone option to get in to the game?

Thanks!


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## macardoso

Charlieman22 said:


> Marcardoso - good run down.  Drinking water from fire hydrant on this one - but that's a norm for me when jumping into something new.  Goal is to not get my lips ripped off.
> 
> My understanding of the components is rudimentary - but your explanation is helpful.  Sorta like not being able to use a modern Amp with an old phonograph.
> 
> For sure I need to determine this.
> 
> Two questions:
> 1.  Assuming DC motors are good (they seam to be) and their respective amplifiers are as well - what would your approach be for setup? (and are these amplifiers inside the large black box?). That is - what would you buy/swap out hardware wise (I assume it would solve for a digital rather than analog input?)
> 2.  Are the modern servos like what I showed in last pic of my first post capable/suitable/desirable for changing to CNC or would I want to upgrade those as well, if I went with the modern clone option to get in to the game?
> 
> Thanks!


Take your time, I think the consensus currently is the price is high and the machine may be worn. If it turns out to be in good shape and you negotiate price, then you might get a really nice machine.

1) I'd assume the motors to be good. Typical maintenance is brush replacement. The drives will be old and I would guess they run tachometers. This might not be what you want. It would limit you to using the Centroid Oak control board ($1820 - $2260 depending on options) or KFlop (cheaper but quite complicated and little support AFAIK - I would not recommend for a first time CNC conversion). Alternative would be to replace with a modern digital DC servo drive which accepts pulse inputs and uses an encoder on the motor. This would cost you for the drives (moderate cost), and you'd need to install encoders on the motors (cheap enough, but a bit of work). We would need to know the motor nameplate data or at a minimum the ratings on the old drives. We would also need to know the DC supply voltage into the drive. This would cost you for the 3 servo drives, plus encoders, but allows you to pick any motion controller and software (~$200 - $600).

AC servos and drives will out perform DC servos, but that might not matter to you. New motors, drives, and cables might be the route to go if the DC drives are too expensive or difficult to find. These also allow you to use any motion controller. Motors will almost guaranteed be a different frame and shaft size from what you have and will require work to interface to the existing mechanics.

2) The servo in your image is a power feed and is not suitable for motion control. Nice to have but only for manual work

I'd reserve $2k-$3k for a conversion. Maybe it can be done cheaper, but we would need to get into the specifics of what is on the machine. 

Mike


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## JimDawson

projectnut said:


> The school had paid a little over $1,400.00 for the machine and the accessories.


The school must have gotten a special deal.  Those machines were were in the $6500 range in the 70's.  Around that time I bought several new clones at about $5500 each, in the mid-90's I bought another new one w/DRO for $8000

That is the oldest Centroid system I have ever seen, well past its prime, and needs to be replaced with modern controls.  The motors and drives are most likely OK since the machine runs.  This means you can reuse the motors, drives, and the existing power supply.  I'm still using the original DC motors and drives with modern controls on my 30 year old machine.  I'm going to make a wild guess here that Centroid was using Copley drives at that time.  In any case they would be analog drives and thus compatible with Dynomotion, Mesa, and Galil products.  And also should be compatible with a modern All-in-One DC Centroid system.

The value of the machine depends on the mechanical condition, the existing controls have no value.  If the ways are not excessively worn, then it should be fine.  These machines run forever if kept properly lubricated and are not abused.  The fact that is has ball screws is valuable if you want a CNC machine, the hard work has already been done.  The fact that it is a manual/CNC machine is very valuable in my book.  Never seen a conversion that still had the original power feed attached, very cool.

At $4500, that does not seem unreasonable, but does require a personal inspection.

Since that old 486 is still running, it might have some value on eBay.


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## macardoso

^^Jim is a smart cookie and definitely knows this end of CNC conversions better than I do. Hopefully we can all help you figure this out


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## wrat

Charlieman22 said:


> All the above.  I had to help him try to start it.  Managed to start it once before it froze and then no amount of un-powering would get it to do anything by make that beep sound from the board.  20 years of dust and grime.


This is easily cured by a good wash and scrub (don't tell him that).   Done it many times.  Even a good airhose shot can do wonders.
So if you wanted to get going, and who doesn't? that would probably solve your onboard problems and leave you with only securing G-code from any of a dozen possible programs or sources.  You can work out the quirks down the line.

If this were me, and I'm old and crotchety, I wouldn't even think about refitting motors and control.  The hardware is as good or better than anything you can get today (in terms of ruggedness and longevity).  Cure the 486 (with a nice bath) and it's ready to rock.

BUT, my gut tells me it's worth every penny of $4500... in 1995.  But today?  Notta chance.  The number $2500 seems more comfy considering the risk.  And every used machine comes with risk.  Heck, even a brand new machine has a little risk.

You might figure any time you buy ANY machine, you're looking to set aside some budget to cure the hidden gremlins.  If you bought a big, simple machine, you'd be wise set aside over a thousand just because.  This is a small, complex machine, so you should do likewise.


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## Charlieman22

Wrat/Jim - Thank you.
Here is where I am at - and it has been super helpful to post here and get some perspectives.
- There is no question that a CNC set up speeds wear.  This machine is still in reasonable shape - I've seen worse - but I agree with the crowd that it is a $2500 machine not a $4500 machine.


JimDawson said:


> That is the oldest Centroid system I have ever seen


- That caused a chuckle.  I'm honored to have posted it...
- For $2500, I could strip off the CNC and restore it to manual with X axis feed while I get my milling teeth.  If/when I decided to go full CNC I could decide what I would want to keep.  He has the original handles and I assume the DRO would still do the job.  If it came with the tools and the rotating table - it might start to feel like a pretty good deal.  Maybe if I threw in some hours of organizing/cleaning his shop, I would find some extra bits and bobs worth keeping - and he would feel like he got a proper value.  

Questions: 
 - If I went back and ran the program a few times in a row, what are my tolerances for returning to zero that should make me feel like I can do some nice work with this thing? At what tolerance do I walk (or is this a poor way to judge)?
 - Pic below of the ways.  There is some wear - but I'm a poor judge based on lack of experience.  Views?
 - It's 3 phase 1HP.  Can someone post a link or two to a basic converter option so I am sure I am grasping what I would need (I hav 220 single phase in my garage)

Thanks again all.  Appreciate everyone helping me get to speed - even if its a crawl.


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## JimDawson

Charlieman22 said:


> Questions:
> - If I went back and ran the program a few times in a row, what are my tolerances for returning to zero that should make me feel like I can do some nice work with this thing? At what tolerance do I walk (or is this a poor way to judge)?
> - Pic below of the ways. There is some wear - but I'm a poor judge based on lack of experience. Views?
> - It's 3 phase 1HP. Can someone post a link or two to a basic converter option so I am sure I am grasping what I would need (I hav 220 single phase in my garage)



I expect a machine to repeat to +/- 0.0001'' or better.  When it doesn't repeat then you have to ask why?  Loose belt, servo drive not tuned, controller needs tuning?  Are any of these show stoppers? No, just minor tune up problems, proper tuning can even overcome backlash in the ball screws to a degree.  With that antique controller you may be at the limit of it's resolution, but I'm betting on a tuning issue.

From the pictures the ways look pretty good for a 40 year old machine.

What you want to convert from 240 single phase to 240 3 phase is a VFD.  For a 1HP machine these are about $75 and up.  

Here is a good one with good support and documentation https://www.automationdirect.com/ad...requency_drives_(vfd)/micro/cfw100c04p2s220g2

Teco and Lenze are good options also.  Stay away from the really cheap Chinese units, however I have had good luck with the Huanyang units and they are well documented.
.


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## Charlieman22

JimDawson said:


> No, just minor tune up problems, proper tuning can even overcome backlash in the ball screws to a degree.


Thanks Jim.
One question this ^ raised.
When I operated it manually - the X axis had a full .05 backlash.
Though I cringe as I type these words: is that a lot of backlash?
(5 degrees on the X axis knob's scale).
He noted to me that he had upgraded the ball screws when he did the conversion - and another response here identified that (from the picture I posted?).
Is there any adjustment to be made in these upgraded type screws? (apologies - for any butchering of the terminology).
Or would that back lash only be addressed with some snugging of the gibs?

Otherwise - I think I have what I need now to have a fair negotiation.
Thanks all.


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## JimDawson

0.05'' backlash would be some serious backlash for a ball screw, but 5 degrees is more like 0.010'' backlash, still a lot for a ball screw.  0.05'' is even a lot for an Acme lead screw with a worn nut.  0.0018''/degree with a 0.2'' pitch screw.  I have about 0.004'' in my X ball screw and concider it worn out and in need of a regrind and repack.  I would be very surprised if there were 0.05'' backlash in the ball screw it self.  That is almost impossible short of a bunch of broken balls and you would feel those crunching if it were in that bad shape.

Having said that, backlash can also come from the thrust bearing, may just need to be shimmed, or even a loose tensioning nut.  If it has double ball nuts then those can be adjusted to remove backlash.  I can't tell from the picture if it has double nuts, but the area of the ball screw I can see in the picture looks good but they don't wear on the ends so that doesn't tell much.  I can see that is a ground screw rather than rolled so a very high quality screw.


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## Charlieman22

I was loath to type it - knowing that I might be misstating.
To be clear - I could move the X axis dial this much without re-engaging in the opposite direction.


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## JimDawson

Charlieman22 said:


> I was loath to type it - knowing that I might be misstating.
> To be clear - I could move the X axis dial this much without re-engaging in the opposite direction.



Yeah, that's about 0.005''.  So the question is where is it coming from, the ball screw or the thrust bearing?  Putting an indicator base on the table and the indicator on the end of the ball screw will tell you if the thrust bearing is loose.


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## wrat

Charlieman22 said:


> Questions:
> - If I went back and ran the program a few times in a row, what are my tolerances for returning to zero that should make me feel like I can do some nice work with this thing? At what tolerance do I walk (or is this a poor way to judge)?


The only really reliable test that i've seen used is the "circle-square-diamond" test.  (sometimes known in a different order like circle-diamond-square, etc.)   Couple of big companies of my employ used that test for many years.
In short, you bolt down (near the middle - you'll be using the perimeter) a piece of material - about 12" square and an inch thick, yes, aluminum.
Then you cut a 12" circle about .250 deep.  Then you cut a circumscribed diamond (square at 45deg) at .500 deep.  Then a square (oriented XY) at .750 deep.  Each layer clearing out excess material.
This gives you about a dozen points to carefully check alignment and repeatability.  Is the circle exactly tangent to the square and diamond?  Is it exactly 12" diameter in every direction?  Is the square and diamond exactly 12" across in both directions down both sides?  Are the steps exactly .250?  Etc. etc.
It's a very thorough and telling test of tracking, columnation, and repeatability.
Obviously, it can be done with any sized piece, but the bigger, the better.
Trouble is, you probably won't get to run anything like that prior to purchase, plus there's a little bit of G-code involved that has to come from somewhere.  But were I to get it, that'd be the first chips I'd make so I'd know what i have and not be chasing it all over.

After all, you don't care if it returns to zero faithfully.  You care if it cuts where it says it's gonna cut, faithfully.


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## tkalxx

Charlieman22 said:


> I was loath to type it - knowing that I might be misstating.
> To be clear - I could move the X axis dial this much without re-engaging in the opposite direction.



.005" of backlash is not crazy bad, but it's also not great - you can still make a lot of good parts with that much backlash. New style motion controllers have the ability to compensate for backlash, but the caveat is they work best on mechanical systems that have as little physical backlash as possible. I highly doubt the centroid controller that is currently installed has this ability. My ground screws have around .0006-.001" of backlash and I've had experience with rolled screws that have as much as .004" from new. If the ballscrews pictured have double nuts, it's possible to eliminate most of the backlash in the nut (if there is any) by shimming. It would be a good idea to check where that backlash is coming from - rule out the thrust bearings first.

As Jim said, those ballscrews appear to be ground screws which is good. A ground screw will have a lot better accuracy compared to a rolled screw (that is, the lead error of the "threads" will have a much tighter tolerance over its entire travel than a rolled screw).


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## Charlieman22

Thanks Gents,
I've thrown in an offer for the machine.
We'll see what happens.
If it goes through - perhaps you guys will help me diagnose and tune (where possible).
That process will give me some basic education on the machine I'm sure.

Travel for the week - then hear back at end of week on my offer.
Will update on return.
Wish me luck...


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## Charlieman22

*edit:  Below is a pic of the type to thing I would like to be able to accomplish - that is likely the most sensitive to spec.
This is a half to a Vespa 2 stroke motor case.
The area where the crank shaft sits needs to be enlarged to fit a specific crankshaft.
The clearance between the crankshaft and these aluminum cases in one area of about 2" of the circumference, should be at least .002 but not more than .004, when complete.  



wrat said:


> After all, you don't care if it returns to zero faithfully. You care if it cuts where it says it's gonna cut, faithfully.


Have no relative experience to place educated bet on weather it will hold my tolerance for what I want to cut as per wrat's comment above - but this type of work will be the measure for me on pass fail for the toughest end of the spectrum of tolerances when cutting.


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## Charlieman22

So, where we left off...
I made an offer - $2500 - for the CNC Bridgeport of this thread.
The gentleman - original owner/ machinist - declined.  
He noted that there was nearly $2K of tools included.  I'm sure that he has spent at least that.
There is a Bridgeport vice and turn table, collets, mills, etc.
I suspect I might get to $3500 - but that is likely the bottom.

I see three options:
1.  Sift through the Craigs List iron scrap for a fully manual clone with no DRO @ $2500 with scrapings still highly visible.  They are 1 in 10 but do come up.
2.  Get one of the top bench mills from PM.  Looks like $6500 all in with power everything and it ties my shoes.
3.  Grab this Bridgeport @$3500

I see myself using the machine to:
 - Modify aluminum 2 stroke cases as in picture above.
 - Machine off excess aluminum after a welding up cases.
 - Bore a 3/4" hole in 1/4" steel plate when fabricating something
 - Make a nicely shaped component in 1/4" steel, or 1/2" aluminum, with curves.
 - Drill a damn hole in something that is clean and neat and centered!

I get how the CNC would be great for making that nice shape - but I am not sure if having the CNC on the machine makes it lousy as a manual mill - _for quick jobs where I don't want to create a cad file just to machine off some material._
For that type of job - I had imagined the PM machine would be ideal...

Would be great to hear it's not the case - and that the BP can be used just standing at the machine and moving the table around in a traditional manner/ rather than creating files on a 486 computer in another room just so I can tell it what to do.  Can you guys help educate me on this?


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## JimDawson

Charlieman22 said:


> I suspect I might get to $3500 - but that is likely the bottom.



Not a steal at that price, but pretty good given it's well tooled.



> I see three options:
> 3. Grab this Bridgeport @$3500



That one ^^^^^^^^^^



> I get how the CNC would be great for making that nice shape - but I am not sure if having the CNC on the machine makes it lousy as a manual mill - _for quick jobs where I don't want to create a cad file just to machine off some material._
> For that type of job - I had imagined the PM machine would be ideal...
> 
> Would be great to hear it's not the case - and that the BP can be used just standing at the machine and moving the table around in a traditional manner/ rather than creating files on a 486 computer in another room just so I can tell it what to do. Can you guys help



Manual as well as being CNC, the best of both worlds in my book.  If I had only one machine in my shop that is exactly what I would want.  I use mine in manual mode all the time for many jobs, sometimes it's just quicker.  I think mine gets used as a manual drill press as much as a milling machine.


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## Charlieman22

JimDawson said:


> Manual as well as being CNC, the best of both worlds in my book.  If I had only one machine in my shop that is exactly what I would want.  I use mine in manual mode all the time for many jobs, sometimes it's just quicker.  I think mine gets used as a manual drill press as much as a milling machine.


Chuckled - drill press...  am certain it will be true -but one that drills where I want it - which takes an act of congress with my current set up.
I was concerned that it being an older set up - there might not be any good means to operate it manually, without a struggle.  
There is some backlash of meaning in it currently...  Perhaps I can beat some of that out of it with some tuning and get it to operate nicely for me in a more point of use fashion (imagining doing it from a remote computer just sounds miserable for odd jobs).

Of course if I could manage to have it manual until that moment when I want 5 of the same curvy components, and then use the CNC capability, that would be ideal.   Perhaps I can convince the gentleman to show me how.

Thanks for the input.  
Will update after my next round of discussions and see where that leaves me.
-CM


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## JimDawson

Charlieman22 said:


> Of course if I could manage to have it manual until that moment when I want 5 of the same curvy components, and then use the CNC capability, that would be ideal. Perhaps I can convince the gentleman to show me how.



Not sure about that machine, but on mine just push the E-stop button and you are in full manual w/DRO.


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## wrat

There is a real chicken/egg situation in this.
Do I need the mill to get some work done?  Or will I get work done because i have a mill?
I've never known anyone that stuck to their version of "I'm just gonna do THIS with it..."  That goes for almost every major tool from forklift to welder.  The inventive craftsman with a task at hand is always doing things he never expected - which opens the door for more tasks.  Soon, you'll be saying, "oh, wait... i can do THAT."

Then there's this:



Charlieman22 said:


> 2.  Get one of the top bench mills from PM.  Looks like $6500 all in with power everything and it ties my shoes.



With a wheelbarrow full of cash, you're still out of luck.  Basically everything is on backorder.  If you can wait until "late summer" - which I suspect will turn into autumn - then you'll maybe be fine if war doesn't break out in Taiwan.  

$3500 for a well-equipped, well-worn, well-tooled machine?  It's certainly not the best or worst deal I've ever heard.


----------



## Charlieman22

Ok Gents,
Don't quit me yet...

What if there was an alternative option to above:
A belt driven PM bench top machine, 32" table, new/unused, & I could have tomorrow.
And it was "basic" meaning no power anything or DRO.

I could install an X feed and DRO - with a custom bracket or two for DRO
And maybe - if I managed to get fancy - or someone here could guid - could figure out how to install a Z power feed (nothing off the shelf from PM).
No powered quill - which would be a compromise on boring I think and perhaps negate possible CNC play? (no experience to know how critical this is to my desired practices).

All in (machine/stand/x power feed) ~ $3500 + delivery (~400)+ DRO(~700?) = $4600 in my garage (and some labor)
Any change of opinion/ thoughts on Z power feed or CNC solutions I would want to understand better?
(I've got a call in to my Bridgeport lead on the other front.  Hope to get back to see and operate this week).


----------



## wrat

Now you've introduced a lot of moving parts and more factors in the equation.  I'm not keeping fully abreast of the dynamics, here.

If you ultimately want to be churning away on an NC machine, you may as well start bare-bones.   Sure, naked PM.  Good idea.  The conversion kit will have motors, scales, and indirectly - through the computer - a DRO.  But you're saying at first not getting a DRO and then later paying $700 for a DRO so I'm not really keeping up, here.

If you ultimately just wanna make some chips, your bench top PM machine is not (generally) gonna be QUITE the machine in heft, rigidity, and wear as that Bridgeport mighta been.  But it'll make nice chips and it's a really nice machine - especially if new.  New matters.  It really does.

Power Down Feed (PDF) is a great feature.  Yes, it's a big player in a well-bored hole, but it comes in handy in straight drilling and a little of everything else.  Maybe not always as critical in 2 stroke aluminum heads, but in a tough steel or some frustrating piece that's way harder than it oughta be (we've all been there), having a very consistent feed is critical to both properly load the cutter and prevent work-hardening.

Not the be-all and end-all, but PDF sure is nice sometimes.  If I was legit looking at cylinder boring as a main activity, I wouldn't even plug the thing in without PDF ready to go.


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## spumco

Bridgeport all the way.

Stiffer, heavier, _significantly_ more flexible for oddball one-off setups like you described.  Since it's already CNC'd, if you hate the control system that part is easy to fix.  Tons of spare parts on fleabay.

You're in LA, there are TONS of used machines there.  30 seconds on LA craigslist revealed about 8 Bridgeports (or clones) for sale in your price range.  There's a clean Enco clone for $2k in Santa Clarita.  They all have PDF, and any 3-phase spindle motor can be run with a 1-to-3 phase VFD.

The only downside to a Bridgeport-like mill is the R8 collet.  Changing tools and having to re-set Z height is a pain... but there are work-arounds and options.  Using the TTS toolholder system is one (for smaller tools).  Royal (and others) make quick-change R8 tool holder systems, but those can get pricey.

But that same downside is also present on any mill with an R8 spindle... including the PM's you're considering.

If you can report back on the Brigeport you're negotiating over... like model and/or control, we might be able to figure out what it'd take to make it really useable in manual mode.  Most of the CNC Bridgeports I've seen are all a bit different - at least the 'aftermarket' ones and not the OEM.


----------



## Charlieman22

wrat said:


> Now you've introduced a lot of moving parts and more factors in the equation


Indeed - and I appreciate ya'll not throwing in the towel!
I'm on a steep learning curve - but every post/response has advanced my understanding of the feature sets, _and refined my own view of what I want._



wrat said:


> Power Down Feed (PDF) is a great feature. Yes, it's a big player in a well-bored hole, but it comes in handy in straight drilling and a little of everything else.


One of those insights I note...



spumco said:


> If you can report back on the Brigeport you're negotiating over... like model and/or control, we might be able to figure out what it'd take to make it really useable in manual mode.


Great.  Posting (some re-posting) of pics of the BP.  Manual will be significant portion of my work - so this is not an insignificant point.  Don't want to be wrestling with the (stepper?) motor's trying to move the table around.
	

		
			
		

		
	












spumco said:


> There's a clean Enco clone for $2k in Santa Clarita.


Ha - trust me - I am watching... I spoke to the guy today in Santa Clarita.   Below is a pic of the ways (saddle?) I got him to send.  Seems kinda well used compared to the Bridgeport ?

Last two pics are the Enco in Santa Clarita.  You can see the Enco's ways are not in as good a condition as the BP.  BP has a spare controller on the shelf.  Not sure the story there.  Would come with it.


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## Papa Charlie

After reviewing this thread, I would like to offer this:

1) You can buy a brand new PM machine for $6.5k as you say, but you still have to buy all of the tooling that is needed and that can add up very quickly.
2) This machine may not be perfect but it does run, seems as though you would be able to do all of the tasks you currently have in mind and depending on the tooling, you may or may not have to buy anything more than the expendables for a while.
3) CNC is great if you are going to do production work, creating the same part over and over. If you are doing that, then you may want to consider a higher end unit with current controls and drivers. But in truth, from your description above, it doesn't sound as though that is your plan. At least for the present. Again, if it becomes your plan down the road. then consider something that will be working as apposed to you working on it.

Without knowing what the tooling is and I mean a detailed list, it is hard to say what the value is. His comment was he has $3000 worth of tooling. What, how old, what condition, etc. It is real easy to spend as much money on the tooling and accessories as you will on the machine. 

Frankly, if it were me, once you have a clear understanding what else he is offering you, make an offer of $3000. You can always go up and he could come down.

The final option is to wait and continue the search. While nice units do come up and sometimes for some pretty good prices, it is more rare for them to have all the tooling in good condition to go along with them.


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## spumco

Charlieman22 said:


> Great. Posting (some re-posting) of pics of the BP. Manual will be significant portion of my work - so this is not an insignificant point. Don't want to be wrestling with the (stepper?) motor's trying to move the table around.



Quick research on the CNC4 controller indicates its a close-loop stepper driven thing.  Dumb steppers, but encoders of some sort feedback to the control.  DOS-based 286 PC interface.  There's a long thread on the LinuxCNC forum about retrofitting something with that control:

https://forum.linuxcnc.org/38-general-linuxcnc-questions/10613-centroid-cnc4?start=0

If it were me, I'd go in to that deal planning (i.e. mentally budgeting) on retrofitting the system.  Even if it works, it can't do helical interpolation and you'll probably spend quite a bit of time just figiuring out how to run the ancient thing.

The steppers are belt-drive, so it should be easy to pull the covers off, drop the belts, and fit a handle on the Z and Y axis.  Use it El Manual for now, maybe leave the steppers as power feeds.

The good part is that all the mechanical hardware is there for an easy retrofit with a PC-based control system.  Three steppers & drives, motion controller, and a cheap PC.  Bamma-jamma, modern control.


----------



## jwmelvin

spumco said:


> Three steppers & drives, motion controller, and a cheap PC. Bamma-jamma, modern control.



Don’t steppers make a machine kind of terrible for manual use, because of the torque cogging when de-energized?


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## extropic

Walk away from the BP. Let it go to someone ready to appreciate it.

Buy a shiny new Chicom or Taiwan machine. You will learn quite a lot.


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## spumco

jwmelvin said:


> Don’t steppers make a machine kind of terrible for manual use, because of the torque cogging when de-energized?


Yep.  That would be miserable, but...

Back-driven brushless servos will generate electricity that the drives may not like very much, especially if they're driven by a 2 or 3:1 belt ratio to get the RPM in the right range for a servo.

And my guess - just a guess - is that the steppers on it are a NEMA frame and it's a little hard to find true NEMA servos.  Not impossible, but not cheap-cheap.  DMM charges extra for NEMA frame/shaft over the metric version, and Teknic isn't giving away the Clearpaths.  Beyond that and you're in to Parkers and Allen-Bradley motors if you want real NEMA frame/shaft compatibility.

But a decoupling connection is a pin-pull away, and steppers are cheap.  Want manual?  Pull a pin and the leadscrew freewheels while the motor & belt just sit there.  There are obviously much more clever ways to decouple a drive system from a shaft, but I was spitballing something quick and dirty.


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## spumco

extropic said:


> Walk away from the BP. Let it go to someone ready to appreciate it.
> 
> Buy a shiny new Chicom or Taiwan machine. You will learn quite a lot.


Always sound advice if the budget permits.


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## JimDawson

spumco said:


> Back-driven brushless servos will generate electricity that the drives may not like very much




All permanent magnet motors can just as easily be a generator if driven.   Steppers are even worse when back driven, they just virtually lock up.  The only motors that seem to work well for manual driving are brushed DC servos.  I like your drive pin idea

The brushed DC servos on that BP are really quite robust and easy to control with the correct hardware, I wouldn't change them, but that antique control needs replacement with a more modern system.


----------



## Charlieman22

Ok - there is drinking water from a fire hydrant - and then there is accidentally getting plowed in the face and washed across the street.
Having picked myself up - and still feeling the weight of my soaked clothing - I am here:
 - Not good to operate manually when motors engaged.  Miserable to turn knobs and bad for electronics even if I could
 - Old system isn't going to do the fancy helical cutting.  Bonus - I now have a name for that cool action I have seen before
 - Slip belts off - or come up with a quick release is an option - tho perhaps the steppers would just be boxes in my way.
 - Add new control that allowed me to move stuff with button pushes rather than physical handle turns? _Jim is that what you were suggesting?  _
 - Buy new - looks like $6000 - $7500 from where I sit for comparable size knee mill - best case.  PM835S with X axis power and DRO = $6K
 - Buy used.

On that last point: the machines I am seeing at 2K-3K all have heavy wear on the scrapings and their own set of issues.
Add a DRO and or an axis drive that has failed and they are all in the $3500-$4K range for my baseline manual operation desires.
Might as well strip off the CNC from this BP - and put the original screws back on and be in just as good a shape with a BP rather than used clone?


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## JimDawson

Charlieman22 said:


> - Add new control that allowed me to move stuff with button pushes rather than physical handle turns? _Jim is that what you were suggesting?_




Not at all.  Here is a picture of my machine, handwheels and servo motors.  This machine can be operated as full manual, 2, 3, or 4 axis CNC with a flip of a switch and a mouse click.  Also of course it will jog with a button push.


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## Charlieman22

Jealous.
Can you walk me through the basic components I would be looking to replace to achieve similar?
Is it largely just the black control box on the BP that would need to be upgraded - or significantly more components?


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## JimDawson

Mainly the controller and the operating software.  Motors and drives can be reused.  I would add linear scales and tie those back into the controller, my preference is magnetic scales.  The only real requirement is that the controller be compatible with an analog command signal, +/- 0 to 10V.  This is an industry standard command signal for axis control.

My machine uses the original motors and drives.  The 4th axis does use a stepper.  I installed a modern industrial motion controller and I wrote my own software to run the system.  There are off-the-shelf controllers and software available.


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## spumco

I forgot about brushed DC motors being back-driveable.  Good point.

But I'm not sure it's got those.  The thread I referenced earlier had three or four people all discussing their Centroid CNC4 system as using steppers, including pics of the stepper drives and motors:




No brushes on that thing.

But I suppose it wouldn't be hard to replace the steppers with brushed DC motors and get some drives while upgrading the controls.

-R


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## slodat

DMM AC Servos bolted in place of the existing brushed DC servos on my Tree J425. I use Centroid Acorn for the control. Very nice machine with the new motors and control.


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## Charlieman22

slodat said:


> DMM AC Servos bolted in place of the existing brushed DC servos on my Tree J425. I use Centroid Acorn for the control. Very nice machine with the new motors and control.


Slodat - very impressive build.  Gave me a good sense of what it would take.
Perhaps my prior analogy of fire hydrant was the wrong one.
Is there a term for when your work gets caught and flung across the garage and sticks in to the wall?
Between your build and Jims' comments, the scope is now more clear, and it's a pretty steep mountain.

May have a chance at a second look today or tomorrow on BP - where I can understand what the tooling that comes with it is.
At that point - I can properly weigh the trade offs of getting a working CNC machine with an aged system that I might modify to allow disengagement - but also provide a learning machine for CNC vs passing.

Much better sense of things from the yesterday's flurry of input.
Thanks guys.

-CM


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## slodat

This is just my opinion, coming from a guy that is not a machinist. There's a lot you can do with CNC mill that you just can't do easily, or practically with a manual machine. With the right control (Centroid in my case), you can use the built in conversational programming to do things you would normally do turning handles, but with a consistent feedrate, etc. You don't have to use CAD/CAM software to run a conversational control. It's crazy how nice it is to have a CNC mill in the shop.


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## Charlieman22

slodat said:


> This is just my opinion, coming from a guy that is not a machinist. There's a lot you can do with CNC mill that you just can't do easily, or practically with a manual machine. With the right control (Centroid in my case), you can use the built in conversational programming to do things you would normally do turning handles, but with a consistent feedrate, etc. You don't have to use CAD/CAM software to run a conversational control. It's crazy how nice it is to have a CNC mill in the shop.


^This is a major draw.
An old Bridgeport, nicely cleaned and polished, that gave me the ability to do this - as well as simple drilling and milling operations - would be a stunning tool to have.

However - if honest - seeing your build was insightful/impressive, but also pretty damn intimidating.
Swapping stepper motors for servo ones - fairly straight forward.
When it came to the controls - I was naively expecting a smaller, sleeker, off the shelf box with some bright lights and a few arrow buttons, that would replace the big black box on the current machine.  Throw in an LCD and Bob was my uncle.

The $8K price tag for taking it there, also was an eye opener.
Have I got my numbers approximately right?


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## slodat

The control piece is easy, point-to-point wiring. While it may look intimidating, it's not hard one circuit at a time. I spent around that amount, if I recall correctly. I never bothered to get an exact total. Things that contributed to the price: replaced the servos and drives, upsized VFD for single phase supply, I used nice industrial wiring supplies, relays, sockets, terminal boards, etc, touch probe, tool touchoff device and more. It *can* be done for less, but I wanted to build an industrial machine that had all of the features it originally had with some new stuff like probing and auto tool measurement.


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## macardoso

The way I see it, if you buy this and disconnect the motors, you have a manual BP with some tooling in good condition for $3500. Not bad. 

As far as the CNC side goes, consider it non-functional but well set up for future work. Sounds like a good investment in my mind. 

If the budget allows, I'd say go for it.


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## JimDawson

macardoso said:


> The way I see it, if you buy this and disconnect the motors, you have a manual BP with some tooling in good condition for $3500. Not bad.
> 
> As far as the CNC side goes, consider it non-functional but well set up for future work. Sounds like a good investment in my mind.
> 
> If the budget allows, I'd say go for it.



What @macardoso said ^^^^^^^  The hard work is done, the mechanical modifications are already in place, and it can be operated as a manual machine, and the controls can be upgraded at your convenience.  I bought my mill in 2012 and ran it as manual only until I really had a need for a CNC in 2013.  I couldn't even spell CNC in 2012, but the machine was too good of a deal to pass up.

Just to put the controller complexity into perspective, here is a complete CNC system on the bench for testing. (This is actually the CNC back gauge controls for our press brake) https://www.hobby-machinist.com/threads/cnc-music-machine.87085/

Consists of a power supply, mini computer, motion controller w/built in stepper drives, and my software.  Not a heck of a lot to it, probably took me about an hour to set it up and get it working.  I paid $112.65 for the 4 axis controller (used), delivered, from eBay.  I think the mini computer (new) was around $175, from Amazon.  This system would run that BP no matter what motors are on it.


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## Charlieman22

Thanks gents.
Appreciate it.


JimDawson said:


> Just to put the controller complexity into perspective, here is a complete CNC system on the bench for testing.


I assume you are referring to the upside down calculator that says Shell Oil?  



macardoso said:


> The way I see it, if you buy this and disconnect the motors, you have a manual BP with some tooling in good condition for $3500. Not bad.


This is largely my perspective.  I want to get back and see what the tooling truly consists of.  
I know there is a turn table of size, and an original BP vice (not Kurt...)
I think the machine is from early 70's.
If he converted it early-mid 80's, then the original lead screws would have seen about 12 years of service.
He told me he has those original parts still.

Waiting to hear back from him to arrange a second visit.
If I can manage - I'll get an accounting of what it would come with.
If it falls through - I will jump back here with other opportunities.
Know it's not a steel - but if its solid and $3500 - that would be a fraction of what a dealer would charge - and the promise of CNC would be there.
Thanks,
-CM


----------



## Charlieman22

Preface - 
Anyone else experience this?
It's like high school.
Can't get a date to save your life, but as soon as you have a girlfriend, they all seem interested in you.
Probably should stop that analogy here - cause my date is potentiall - lets just say - kinda big around the hips.

Waiting to hear back from my Bridgeport guy.
Very quiet.
Then today got contacted by someone else.
"Would I like a free mill?"
"Old Webb CNC.  CNC broke 10 years ago"

That is every piece of detail I have.
Tomorrow - I will drive 1.5 hours to have a look.
No pictures. No idea what model, year, or condition.
For all I know, it has been sitting outside for a decade.
On the other hand, it could be sitting in the corner of a pole barn.
Oh - and they said its a knee mill and it weighs about 4000 lbs.

Seriously - you can't make this stuff up.
Maybe no more than a rusty ship anchor.
Wont know til I see.

Question: What am I looking for?


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## JimDawson

Charlieman22 said:


> Old Webb CNC.



Got one exactly like it, very nice machines.  If it looks like most of the parts are there.... Drag it home.  If it's not frozen with rust, so much the better.  I would take a trailer with me.


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## Charlieman22

Thanks Jim.
That was the vote of confidence I was looking for.

I managed to get in touch with the guy who owns it - by text.
Still know precious little.
Says it was inside until a month ago.
Will send me detailed pics in the morning.
Don't expect perfection... its free.

Said he had a fork lift and would be happy to load.
However - If he were to load it on a trailer tomorrow - I don't know how I would even get it off.
My plan is to build a steel and wood pallet for it over the weekend - like below - as that would allow me to unload with pallet jack - I think.
I can measure it up tomorrow so I know sizing and hole placement.
Leaving it over the weekend puts some risk in play - but I like to deal directly with people - and if he says it's mine - I will take his word.

Curious - what machine/era are you guessing I will find?
First look at pictures I have seen online for "Webb CNC" show no handles at all for manual movement?
Pic below of the type of skid I was considering.  Thoughts on this as a permanent base?
Sunbelt rents a drop bed trailer that seems like it would work.


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## JimDawson

The pallet looks good, so does the trailer.  But remember these are top heavy, and even coming down the small ramp on the drop deck trailer can be exciting.  It is only about a 2 inch drop on the incline but you are going to want to ease is down with a come-a-long.

Well if you are lucky it will be this model with the 4VK frame.  There are 3 different models, 3VK, 4VK, and 5VK.  the 3VK is an exact BP clone, the 4VK is a heavier (by about 1000 lbs) machine and a bit larger than a standard BP.  The 5VK is a bit larger still.  The 4VK has square ways on the saddle, the 5VK has square ways on both the saddle and the knee.  Late 80's


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## Charlieman22

Good break down.
Know how to spot the model now.
Thanks.

I've passed on what looks like a nice Lagun FTV2 because its larger than I want... 
Will be ironic if this is the 5VK...
Kinda suspect that's what I'm gonna find.
Only way to know is go look.

That said - free is good! - and if I can actually move it for a couple hundred bucks and some carefully coordinated winching - it'l be hard to pass up.
Look out for some pics tomorrow.
I'll post if I receive some in the AM - and when I get out to the machine around lunch.
Feedback of course desired and welcomed from all.

-CM


----------



## Papa Charlie

At the price you are getting this for, your gas to go get it. Renting a trailer and a fork lift once you get home would still be a cheap option with this unit.

If I might ask, how did the owner of the mill come to make this offer? Did you advertise for a mill? You indicate that it is a 1.5 hour drive, so I assume it is someone you may not know.

Thanks


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## Charlieman22

Papa Charlie - will happily share the story.
Even if it crashes and burns - its still a pretty good one.
Lemme see if I can lock it down first - you know how these things can fissile...
Pic's to follow.
Collecting tools now to bring along for quick look and measure.
No go on truck rental - rental company announced they didn't have a truck for me about 30 min ago...
Working with what I'm being dealt - both good and bad.


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## Charlieman22

Just got a pic. 
is this the 5?
Will see it in a couple hours live. 
melt me know what pics y’all would like to see if there are any particular ones.


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## JimDawson

Yup, I think that is a 5VK, CNC only, no hand wheels.  Short table.  Looks like a project. 

May as well drag that sandblast cabinet home also


----------



## Charlieman22

Ok story still to come...

Here are the details on the machine - picture heavy.
Its a 5VK.
Owner said it was running - all working - and it "lost its perimeter set".  was shoved to the side, and sat for a decade.  
A month ago - they started a clean out - and declutter.
Now it's outside.

Condition says that at least some of that is true.
Machine does not have a lot of rust on it.
Looks like it made its last cut and hasn't been cleaned since.
Smells of decade old cutting oil - past even being sticky.
Cleaned off a few spots - surface grease and dust but nothing unremovable.
Nothing looks badly rusted.  
Grease and dirt version of cosmoline protectant you could say.

Mostly seems all there.
Kinda stunned.
Even had a coolant tray.
Power draw bar.
Central oiler
A couple of plates missing was most I could find.
Buttons not worn out.

I mean - Its communist dark gray - my least favorite color
And It is enormous for a garage machine.
And there are no hand wheels of any kind for moving the table
But I kinda love it.

Would like to get it out of there before any minds change - but can only move so fast.
It weighs 4K#s.
Can turn everything by hand smoothly with what I tried.

Uploading a few sets of pics


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## Charlieman22

CNC cabinet


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## Charlieman22

Motor & VFD.
No clue what HP this thing is.
VFD was nice surprise.


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## JimDawson

That's a lot of machine, but a bit dirty. 

Looks to be pretty much complete.  The spindle motor is 5HP, machine looks to be wired for 240V.

The only thing I didn't see in the pictures are the servo drives, they have to be in the electrical cabinet somewhere.


----------



## Charlieman22




----------



## Charlieman22

Lotta pictures...
(So much for my elegant small Bridgeport)
What do you make of the "it was working until it lost it's perimeter set"?
The intonation was - all spindles and movements were operational - but the computer couldn't understand where the positions were.


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## JimDawson

The parameters and many times the operating system are saved in volatile memory, held there by a battery.  When the battery goes dead, the parameters are gone.  The battery would normally be replaced every few years, guess they missed the warnings, and didn't have a hard copy.  This is not that unusual in older machines.

Once the parameters are gone, everything should be fine, but the computer has no idea what to do with anything and has pretty much lost its mind.


----------



## slodat

I would drag it home. That’s a perfect candidate for a retrofit and would make a nice machine.


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## mattthemuppet2

hard to argue with free. Looks like it'll be awesome for a garage shop - compact but weighs a couple of tons!


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## extropic

I thought you were insistent about having a manual capability?

Edit: insistent, not instant


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## Charlieman22

Papa Charlie said:


> At the price you are getting this for, your gas to go get it. Renting a trailer and a fork lift once you get home would still be a cheap option with this unit.
> 
> If I might ask, how did the owner of the mill come to make this offer? Did you advertise for a mill? You indicate that it is a 1.5 hour drive, so I assume it is someone you may not know.
> 
> Thanks


So about the story...
I had just watched a well known YouTuber yesterday who was offered a Bridgeport.
Looked like you could serve dinner off it.
The ways were unscathed and chromed.
The paint was perfect.
The aluminum was all aluminumy and pretty.
And it operated as smooth as glass.

And I thought to myself.  Self: why does this never happen to you?
And as I closed the video, one of the many alerts popped up - and this one was for some scrap sheet metal.
Only at the bottom of the add, it said: "and I also have a mill you can have if you have a big trailer"
So I immediately hit respond, and asked - exactly what kind of mill is this thing I can have?
And he said: "An old Webb.  CNC".
Until today - that is what I knew about it.

So this morning - I brewed myself a coffee and drove 1.5 hours to see a man about a mill...
Pictures above tell the rest of the story.
They restore helicopters - and had decided they needed it out of the way.
It had apparently sat in the corner of the shop for a decade.

So it just kinda fell to me - though as these things go - until its in the garage - you never know.
I'm thinking through what I could do to best suit my needs.
I'm hungry to have a working mill - that's where this whole thing started before I found myself in a parking lot with old helicopters.

Some options I'm pondering:
1.  Strip off the CNC.  Turn it in to a manual.  Hey - I got it for free!  Put on a DRO and an X axis feed.  Maybe put a potentiometer on the existing quill feed and use that as a power quill with no handle (cause I don't know how I would put on a handle.). Perhaps even tear it down, scrub it, paint it my favorite color of green, polish up the aluminum and steel bits.  Have a compact 4000lb garage manual milling machine.
2.  Put a battery in it, tell the computer where the parameters are (hey computer - they are over here!  everything is ok!) maybe even skip the  paint part, and figure out how to use it.
3.  Take it modern.  New servos motors, controller, some kinda screen, etc. etc.

Any thoughts on above?


----------



## JimDawson

I think any of the above would be viable options.  #2 would be the most difficult, but Webb is still in business, so maybe.

I would start by cleaning it up and painting your favorite color. 

Adding handwheels should be very easy.  You should be able to lash up a manual quill operator.  Add a DRO and you're almost making chips.  You may need to replace the VFD with one that will run on single phase (I'm assuming you don't have 3 phase in your garage) 

The existing servos are brushed DC servos with velocity drives, commanded by an analog +/- 0 to10V signal, an industry standard.  Compatible with many modern retrofit systems.  I still have the original brushed DC servos on my machine.  The servo drives on that machine have a 3 phase dc power supply, so a bit of modification would be needed there, not difficult and really only a few bucks (maybe $10?)  The nice thing about brushed DC motors is they are very compatible with manual operation via handwheels.

Looks like a fun project.


----------



## Papa Charlie

I am with Jim, you can make it whole again, or convert it to manual, or just clean it up, spend the least amount to make it somewhat functional. Once you have completed any of these, you have an operational mill. You may decide that you want to take a different path and at that time you could turn around and sell the fully operational mill and use that money, along with what ever else you want to add to that and get something else that at that time will fit your vision for the future. 

I see units that are in poor condition going for at least $1500 and up to $2500. So you could come out ahead regardless.

It just boils down to what you want to do. You now have options.


----------



## Charlieman22

All - thank you for the input.  Helpful all the way around.


extropic said:


> I thought you were instant about having a manual capability?


*Edit.  Missed this previously.
True - I have been all over the board - and you guys have been patient.
At the outset - I imagined myself spinning a handle with smooth action until the DRO says I have it perfect.
The usual challenge of reality then arose: you can have it quick, exactly as you like, or at a really good price.  Not all three.
So i'm trying to stay fluid and hoping a path will show the way - and with a bit of flexibility - find some magic in the end.
When this showed up - heavy/accurate/powerful/ and free... my mind went into overtime on how I could wrangle the asset into a solution.




JimDawson said:


> I think any of the above would be viable options.  #2 would be the most difficult, but Webb is still in business, so maybe.
> 
> I would start by cleaning it up and painting your favorite color.
> 
> Adding handwheels should be very easy.  You should be able to lash up a manual quill operator.  Add a DRO and you're almost making chips.  You may need to replace the VFD with one that will run on single phase (I'm assuming you don't have 3 phase in your garage)
> 
> The existing servos are brushed DC servos with velocity drives, commanded by an analog +/- 0 to10V signal, an industry standard.  Compatible with many modern retrofit systems.  I still have the original brushed DC servos on my machine.  The servo drives on that machine have a 3 phase dc power supply, so a bit of modification would be needed there, not difficult and really only a few bucks (maybe $10?)  The nice thing about brushed DC motors is they are very compatible with manual operation via handwheels.
> 
> Looks like a fun project.


Jim - 
There is some gold in there - and some surprises...
(Shucks!  I was just celebrating the fact it had a VFD that was going to make my life simple and save me some bucks!)

Suspect the first call from the guys giving it away would have been to Webb - so perhaps there is no real solution to #2 - which is what made it free.
Webb must get that call fairly often...
"You've lost your parameters?  Press 2 to hear us say no!"

*Ok couple specifics and a basic plan:*
- if I wanted cost effective retrofit system that would allow conversational programing and allowed perhaps a smaller box (that thing is killing me) - are there some off the shelf solutions you guys could point me at to browse?  Starting at zero here.
 - I've circled and numbered what I perceive to be components of the existing system - could someone help me with what would remain with a retrofit, what would go, and the basic nomenclature of the components so I can speak about this with a bit more knowledge?
 - would the VFD Jim suggested previously still apply or am I in a whole new realm with 5HP a motor?

*My present thinking:*
 - Get a VFD to power up the motor & use a power supply if I had to to test the DC motors separately (I have a 15V - 50amp one that might work?). Not sure how else I could tell them to spin?
 - Schematic of lower end below - first thought would be to tap the face of the Timing Belt Pulleys 13 to mount an adapter of some kind to a handle.  The shaft will be too short to give me access to the key (2) otherwise.
 - Schematic of head below - same treatment here with Timing Belt Pulley (14).  The cover was missing and I actually shot a picture of this today - (the somewhat rusty timing belt pulley pic below).  This would mean my quill would have a horizontal wheel which is weird - but if I put one on with a handle - perhaps it would be suitable/livable.
- If everything spun and moved - tear it down/ clean/ learn the machine a bit - perhaps even paint if I wanna get fancy.  This is gonna be a big job.
 - Then I could either reassemble with conversion kit - or hold on that - add a DRO - and try and make chips manually - depending on the (perceived) complexity and cost.

All - I am really starting at ground zero here - so if you have a few ideas or opinions - please fire them.
 - This thing is so damn dirty - would it be a crime of rust creation to hit it with a power washer before it was loaded up to knock off the thick stuff and leave it at the site I am taking it from?!
 - Handles!  I wouldn't even know where to start looking - which ones are best for shape - or if some are made with some kind of face mount rather than spline so I could just bolt them on the face of the drive pulleys.
Any and all brainstorming is absolutely welcome.
Feels like I have a path here to entering the world of mills/machining.
Thanks gents.
-CM


----------



## JimDawson

Giving it a bath before dragging it home would not be out of the question, especially if you have some Santa Annas blowing and about 2% humidity that day. I would take about a gallon of WD40 to spray it down after washing.

A very interesting design on the X axis drive.  The ballscrew is fixed to the saddle and the ball nut moves with the table.  Never seen that before.  Should make for a very robust system.

A manual Z axis is a little more challenging on this machine, but I'm always up for a good engineering challenge.  The goal would be to switch between a conventional manual lever and CNC, switchable with a mechanical lever.  I need to think about this one a bit.  That's the way mine works. Mine started out life as a manual only, but I can now switch between CNC and manual with a flip of a lever.

#1 Reversing contactor for spindle motor. Remove, not needed.  Has been replaced by the VFD
#2 Servo Drives. Keep, needs some slight modification to run on 120VAC single phase.  I'll explain the 120VAC later
#3 Main disconnect & fuses. Keep
#4 Supplementary protection (fuses). Keep
#5 240/120 VAC Control Transformer. Keep
#5A Small contactor. Coolant pump relay?
#6 Servo drive power transformer. Remove, not needed.
#7 Terminal strip. Keep, always useful.
#7A Small transformer at bottom. Not sure what it's for, need further information.
#8 Ice cube relays.  May be useful, depends on coil voltage.
#8A DC Power supply section for servo drives (behind the brown panel). See #2 above

You are going to basically rewire the entire panel.

New VFD.  I have this one on my 5HP air compressor running on single phase, no problems in about a year or so of use.


			https://www.amazon.com/Variable-Frequency-Controller-Converter-HUANYANG/dp/B077KSN4C5/ref=sr_1_11?dchild=1&keywords=10%2Bhp%2Bvfd&qid=1621649328&sr=8-11&th=1
		


Hand Wheels, these should be easy to attach to the existing timing pulley.
You will only forget to fold the handle one time when in CNC mode.   





						Amazon.com: uxcell a13110700ux0953 16 mm x 150 mm Inside Ripple Hand Wheel Black w Folding Revolving Handle : Industrial & Scientific
					

Buy uxcell a13110700ux0953 16 mm x 150 mm Inside Ripple Hand Wheel Black w Folding Revolving Handle: Hand Wheels - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



					www.amazon.com
				




I would go with magnetic scales for the DRO/encoder feedback to the CNC.  I buy direct from Ditron in China.  I'll get part numbers later.  Then comes the question: Spend $150 on a DRO display or jump straight into the CNC controller which is going to have the DRO display built in.  You would still be able to use it manually.

The CNC controller/computer hardware you can hold in one hand.  The only large thing is the monitor, a 27'' suits my old tired eyes very well.  Refer to my post #50 above for a complete CNC system.

Forget about conversational programming, it's really easier to draw it up and post the G code.  Or sometimes I just hand write the G code for really simple stuff.

What a fun project.


----------



## extropic

Charlieman22 said:


> snip>
> 
> True - I have been all over the board - and you guys have been patient.  snip>
> 
> All - I am really starting at ground zero here - so if you have a few ideas or opinions - please fire them.  snip>



First, I'll say that Jim is a perfect guy to guide you through the refurbishment of the WEBB, so you're in good hands.

However, saying "I have been all over the board" is, IMO, a minimalistic description.

Since you're a self described noob to machining and H-M, please reply with some description of your personal knowledge, skills and/or experience that you think will be applicable to hobby machining in general and machine rebuilding specifically.

Questions about "how can I . . ." are much easier to answer when we have some idea what the requester has to work with.

Also, the two projects (Bridgeport vs WEBB) are vastly different in magnitude. The $4500, full asking price, for the Bridgeport deal is going to seem REAL attractive well before you cut any chips with the WEBB.


----------



## Charlieman22

Now that response caused an outloud chuckle.
Twice.



JimDawson said:


> Giving it a bath before dragging it home would not be out of the question, especially if you have some Santa Annas blowing and about 2% humidity that day. I would take about a gallon of WD40 to spray it down after washing.


I will be judicious with the water - and generous with the WD.  Check.


JimDawson said:


> A very interesting design on the X axis drive. The ballscrew is fixed to the saddle and the ball nut moves with the table. Never seen that before. Should make for a very robust system.


Franken mill.  5 HP, 4K pounds, small footprint, ugly like no other.  Maybe we can find a nice angle to shoot a picture from - but have the sense I could stumble into something that cuts chips and is more forgiving of my ignorance than I deserve.  I'm in.


JimDawson said:


> A manual Z axis is a little more challenging on this machine, but I'm always up for a good engineering challenge. The goal would be to switch between a conventional manual lever and CNC, switchable with a mechanical lever. I need to think about this one a bit. That's the way mine works. Mine started out life as a manual only, but I can now switch between CNC and manual with a flip of a lever.


Goal now understood.  Will ponder as well as I disassemble.  Sometimes simple is best.


JimDawson said:


> You are going to basically rewire the entire panel.


Will finally learn.  Electrical will be the part I need the most hand holding on.
Unless its something else...  ¯\_(ツ)_/¯ 


JimDawson said:


> I would go with magnetic scales for the DRO/encoder feedback to the CNC. I buy direct from Ditron in China. I'll get part numbers later. Then comes the question: Spend $150 on a DRO display or jump straight into the CNC controller which is going to have the DRO display built in. You would still be able to use it manually.


Mill is free.  If we blow $150 on a DRO that becomes redundant down the road - it would still be a steel.  Let's just put one on.  I'll use it on my second mill someday   Point me in the right direction.



JimDawson said:


> The CNC controller/computer hardware you can hold in one hand. The only large thing is the monitor, a 27'' suits my old tired eyes very well. Refer to my post #50 above for a complete CNC system.


Large screen is highly preferred over Star Trek oscilloscope sized screen.  If I am going to take the time to actually clean and paint this beast, the least we can do is outfit it with a nice screen.  Tho I gotta say - 27" is pretty impressive from 3 feet!  



JimDawson said:


> Forget about conversational programming, it's really easier to draw it up and post the G code. Or sometimes I just hand write the G code for really simple stuff.


Now that surprised me.  I can barely operate BB code - but will keep an open mind.  



JimDawson said:


> The CNC controller/computer hardware you can hold in one hand. The only large thing is the monitor, a 27'' suits my old tired eyes very well. Refer to my post #50 above for a complete CNC system.


Ok - don't laugh.  When the term "Controller" is used - is it everything in the box #1-#8 or is it a physical component. (cringed when I typed that)


extropic said:


> Since you're a self described noob to machining and H-M, please reply with some description of your personal knowledge, skills and/or experience that you think will be applicable to hobby machining in general and machine rebuilding specifically.
> 
> Questions about "how can I . . ." are much easier to answer when we have some idea what the requester has to work with.


My experience with milling machines specifically - and machining itself - is razor thin.
I'm here to learn.
With a little luck - down the road - I'll be able to contribute in return.
As for machine rebuilding - Its a perfect apprenticeship in my view.
I'll learn a ton - and its a great place to start before I make the first chips fly - with good long term benefit.


----------



## JimDawson

Charlieman22 said:


> Ok - don't laugh. When the term "Controller" is used - is it everything in the box #1-#8 or is it a physical component. (cringed when I typed that)



You haven't looked in the top box yet, there is a reason that it is that large.  The lower electrical cabinet is just the heavy power handling stuff, not the control electronics.


----------



## Charlieman22

Ha! 
Forgot about that second box.
Which is hard to believe - because it's larger than the head of the machine itself.
Forest through the trees!

Ok - honkin big box with screen at front = controller and has computer in it.
Becomes much much smaller and is matched with much larger flat screen in upgrade.
Other box is basically power handling stuff.
Will ponder a lower profile solution - but most of the actual stuff in there is needed.

Ok - last of the day - 
	

		
			
		

		
	



What if I used "virtual" handles something like these?
Then could just mount on outside of timing belt housing as if they were physically connected.
Viable?
Nice to use?
Bad idea?
Would it fly?


----------



## JimDawson

Ditron DRO + Magnetic scales
1)D100-3V 3axis display
2)DMR200 1um read head, 4 required
3)MS200-3M (3 meters tape)
Factory direct from Ditron. sales@dcoee.com
http://www.dcoee.com/



Yes, those manual pulse generator hand wheels are a reasonably good solution, you just need to make sure you get the 6 terminal ones.  Might be the best solution to the manual quill problem.  The biggest problem is that they lack any tactile feedback when feeding so you can't really feel what you are doing like you can with a mechanical handwheel.  I do have one on my CNC lathe and sometimes do some simple turning with it because I have no manual cranks on that machine.


----------



## JimDawson

You are going to completely gut that top box.  Maybe reuse the push buttons.  There is actually enough room in the main electrical cabinet to stuff the computer hardware in there also and just use a monitor/keyboard mount in place of that big ugly box.  Maybe something like this





						Amazon.com : Mount-It! MI-7921 Sit-Stand Desk Mount Workstation, Height Adjustable Standing Desk, Ergonomic, Monitor, Laptop, and Keyboard Mount, 22, 23, 24, 27 Inch Monitors, Gas Spring Arm, C Clamp Base, Black : Office Products
					

Amazon.com : Mount-It! MI-7921 Sit-Stand Desk Mount Workstation, Height Adjustable Standing Desk, Ergonomic, Monitor, Laptop, and Keyboard Mount, 22, 23, 24, 27 Inch Monitors, Gas Spring Arm, C Clamp Base, Black : Office Products



					www.amazon.com


----------



## Charlieman22

JimDawson said:


> Ditron DRO + Magnetic scales
> 1)D100-3V 3axis display
> 2)DMR200 1um read head, 4 required
> 3)MS200-3M (3 meters tape)
> Factory direct from Ditron. sales@dcoee.com
> http://www.dcoee.com/



Vision for machine & components needed coming together - Like it!
Above list seams to have reading heads, tape , and DRO display.
Is there also some extruded track of some kind the tape is going to fit in?



JimDawson said:


> Yes, those manual pulse generator hand wheels are a reasonably good solution, you just need to make sure you get the 6 terminal ones.  Might be the best solution to the manual quill problem.  The biggest problem is that they lack any tactile feedback when feeding


Ah.  Ok.  Tactile much nicer.  Makes sense.
As I have no other cutting tools, perhaps I could start with a set of cheap digital ones - then mill my own adapters as a project - to allow connection of some hand wheels.
Note to self - beware of servo spun spinning hand wheels on fingers and mid section...


JimDawson said:


> There is actually enough room in the main electrical cabinet to stuff the computer hardware in there also and just use a monitor/keyboard mount in place of that big ugly box. Maybe something like this


This I like.  Would even consider optimizing placement & depth of the lower box once I figure out what will go in there.  Honkin' big control box at eye level may be functional - but just pure ugly to my eye currently.  Screen very nice.

Ok - quick recap to see if I have this right and for basic budgeting.
*For manual operation - (WITHOUT power feed using) but no CNC:*
1. Magnetic cales
2. Reader
3. DRO box
4. New VFD
5. Temporary digital dials or manual knobs if I can make them work
6. Single phase power supply(s?) for my servos

Above gets me in manual operation - I don't think it gives me power feed (for that I believe I will need a Controller?)

*To get to power feed and CNC functionality I would add:*
1.  CNC controller (can you give me an example? - I see prices ALL over the board here)
2.  Nice LCD screen
3.  Key board? (or can I go touch screen and do it all on screen?)

There is also the matter of tooling... Note this thing doesn't even have a chuck or collet holder on it.
That can come later...
Lemme know if I missed/misunderstood something.


----------



## JimDawson

Charlieman22 said:


> Vision for machine & components needed coming together - Like it!
> Above list seams to have reading heads, tape , and DRO display.
> Is there also some extruded track of some kind the tape is going to fit in?


No track needed.  You will need to build some aluminum rails for the quill and knee.  We'll get to that later.
Here is how mine is mounted on the X axis.





> Ok - quick recap to see if I have this right and for basic budgeting.
> *For manual operation - (WITHOUT power feed using) but no CNC:*


1. Magnetic scales Tape
2. Reader
3. DRO box
4. New VFD
5. Temporary digital dials or manual knobs if I can make them work
6. Single phase power supply(s?) for my servos

The digital hand wheel (Manual Pulse Generator) MPG would connect to the controller, there is no way to operate the existing servo motors/drives directly from the MPGs.  The existing servo drives are analog input devices.  The MPG would connect to an unused encoder input on the controller, and there would need to be some software on the controller to tell it what to do with the MPG input.



> *To get to power feed and CNC functionality I would add:*
> 1.  CNC controller (can you give me an example? - I see prices ALL over the board here)
> 2.  Nice LCD screen
> 3.  Key board? (or can I go touch screen and do it all on screen?)


I have been avoiding this subject until we had a better handle on what we had to work with.  CNC control systems range from virtually free to '' you can't afford it''.  There is a lot to concider before choosing a system, the axis drive motors partly dictate the controller.  Most modern axis drives are stepper or servo motors and drives, but these don't lend themselves to smooth manual operation thus the desire to use the existing brushed DC motors and drives if possible.

By definition, a servo system is a *closed loop *system.  The term *servo* does not define a motor type contrary to what the marketing types would have you believe.  Your home heating/AC system is a servo system, the loop is closed by the thermostat and you, _as the user_, define the comfort level _parameter_ by setting the thermostat.  Another common example of a servo system is your car.  You, _as the controller_, take various inputs from what is going on around you, process the data, and output the appropriate (we hope) actions to the steering, throttle, and brakes.  On a machine tool, the loop is closed by the encoder feedback to either the servo drive or the controller.

On the low end there is the *open loop* stepper stepper system, this is the most popular for many hobby uses because it's inexpensive.  In this case the controller sends out a pulse train and direction signal to the stepper drive but there is no feedback and the controller just assumes that the motor is doing what it is commanded to do.  But the controller has no idea what is actually happening.  Not the best for accurate work, but it does work pretty well.  Could be operated directly with the MPG handwheels without any CNC capability, I actually tested this out of curiosity.

As the sophistication goes up so does the cost, but you have a good budget for this project so cost, within reason, is not really a factor.  The only real requirement is that the system be compatible with the existing analog command input, and it is Closed Loop.  You will need a motion controller.  My personal favorite is Galil Motion Control products. These are industrial class motion controllers.  These can be purchased directly from Galil, or there is a lot of used Galil hardware on eBay.  I purchase from both depending on the application.  https://www.galil.com/

So, given the existing analog commanded hardware there are a few relatively inexpensive options:
Mach3/4 https://www.machsupport.com/
Dynomotion Kflop/Kanalog https://www.dynomotion.com/
Centroid All-in-One DC https://www.centroidcnc.com/centroid_diy/allin1dc_cnc_controller.html
CamSoft http://www.camsoftcorp.com/
My software (free)

Mach3/4 is a software motion controller/CNC.  Can be used with Galil or Dynomotion products
Dynomotion and Centroid both make their own motion controller boards, and provide the software with their products.
CamSoft uses Galil motion controllers as does my software.

Support on all of the above is pretty good.

Here is a screen shot of my current version running on my mill



There is no reason to make a decision on CNC software/controllers just yet.  But there is no practical way of using the machine manually without mechanically coupled handwheels.  You are going to want to have a keyboard and mouse.



> There is also the matter of tooling... Note this thing doesn't even have a chuck or collet holder on it.
> That can come later...
> Lemme know if I missed/misunderstood something.


Pretty sure that spindle is NMTB 40 (I think Cat 40 will also work in that spindle), you'll need to measure it.  It could be a 30, but with 5 hp most likely 40.  #40 tool holders are readily available on the used market, probably the most common holders and available in every configuration imaginable.

So something like this.  https://www.shars.com/nmtb-40-er32-er-collet-chuck-tool-holder


----------



## Firstram

Seems like you've done this before!


----------



## JimDawson

Firstram said:


> Seems like you've done this before!


Once or twice


----------



## Charlieman22

JimDawson said:


> Once or twice


Indeed



JimDawson said:


> No track needed. You will need to build some aluminum rails for the quill and knee. We'll get to that later.
> Here is how mine is mounted on the X axis.


Love how low profile this is.


JimDawson said:


> The digital hand wheel (Manual Pulse Generator) MPG would connect to the controller, there is no way to operate the existing servo motors/drives directly from the MPGs.


Struck me after I typed it.  Yup.  Gonna have to solve how to attach some handles to my belt timing cogs.


JimDawson said:


> but these don't lend themselves to smooth manual operation thus the desire to use the existing brushed DC motors and drives if possible.


I am all-in on this.  Felt like stars aligned a little when you mentioned that the DC motors are compatible with hand turning.  Not like I am running them 24/7.   Think its the right choice on this one - and of course - its already on there...


JimDawson said:


> You will need a motion controller. My personal favorite is Galil Motion Control products.


Quick look at Galil shows they have all sorts: single axis, multi axis, ethernet, ethercat, ether dog...  
Not quite able to navigate yet what's what.  May need just a bit more on hardware front needs.
Software combinations you listed make sense.

Two other factors that may or may not effect thinking.
 - I have cat6 run to my garage.
 - I prefer to use a Mac (the onion peals back its layers...)

Thanks for the run down Jim.
Components to operation starting to sink in.


----------



## Charlieman22

*edit - meant to mention/ask:

The guys that are giving me the machine said I would have to find a "post processor".
Specifically - they said: "What you need to really consider before you start to buy a controller is, can you get a post processor for the cad/cam software and controller" 

Can someone help me parse that?
I really didnt understand what they meant.


----------



## JimDawson

Charlieman22 said:


> Indeed
> 
> 
> Love how low profile this is.
> 
> Struck me after I typed it.  Yup.  Gonna have to solve how to attach some handles to my belt timing cogs.
> 
> I am all-in on this.  Felt like stars aligned a little when you mentioned that the DC motors are compatible with hand turning.  Not like I am running them 24/7.   Think its the right choice on this one - and of course - its already on there...
> 
> Quick look at Galil shows they have all sorts: single axis, multi axis, ethernet, ethercat, ether dog...
> Not quite able to navigate yet what's what.  May need just a bit more on hardware front needs.
> Software combinations you listed make sense.
> 
> Two other factors that may or may not effect thinking.
> - I have cat6 run to my garage.
> - I prefer to use a Mac (the onion peals back its layers...)
> 
> Thanks for the run down Jim.
> Components to operation starting to sink in.


Cat 6 in the garage is handy, but not a factor in any of this.

I'm not aware of any system that will run on a Mac, you will learn to love (or hate) Win10 (or perhaps Linux, there is at least one option there)



Charlieman22 said:


> *edit - meant to mention/ask:
> 
> The guys that are giving me the machine said I would have to find a "post processor".
> Specifically - they said: "What you need to really consider before you start to buy a controller is, can you get a post processor for the cad/cam software and controller"
> 
> Can someone help me parse that?
> I really didnt understand what they meant.



They were assuming that you would try to breathe life into that antique controller.

The post processor is the final step between the drawing and the generation of the G code to run the machine. It is a file that takes the tool paths generated by the CAM program and formats them into something the CNC software can understand.

Drawing>CAM>post process>G code.

The post processor is specific to the CNC software and CAM package.  Every system I listed above has post processors readily available for most CAM software packages.


----------



## spumco

This is getting pretty exciting!

Im reluctant to offer up control/drive suggestions as I dont want to overload the self-described Newbie, but I cant help myself.

None of the below is intended to contradict Jim's basic plan, but here's some food for thought:

1. LinuxCNC can handle analog +/-10v drives using card from Mesa. Encoder feedback to the Mesa as well.  So if you aren't emotionally capable of going with Windows, you have an option that allows you to keep existing motors and drives.

2. There are DC servo drives that take step & direction inputs.  That opens up other controller options - most of the ones you've probably been looking at on the internet. Some may take AC input, meaning you wouldnt have to get a bit ac-dc power supply to power the drives.

Both let you keep the dc servos for handwheel compatibility. Im not going to bother you with part numbers or details, but just know there are options that dont require a 100% gut-job if a reasonably priced Galil seems difficult to source.

Following with interest.


----------



## Charlieman22

spumco said:


> This is getting pretty exciting!
> 
> ...
> 
> Following with interest.


Spumco:  Thanks!
Welcome the additional info.
It's helpful for me to gain a broader understanding - which is growing leaps and bounds thanks to this thread/Jim's master class.


spumco said:


> 1. LinuxCNC can handle analog +/-10v drives using card from Mesa. Encoder feedback to the Mesa as well. So if you aren't emotionally capable of going with Windows, you have an option that allows you to keep existing motors and drives.


Appreciated.
Though I didnt mention - I run my Mac with both its operating system and a virtual machine - running... windows 10.
I do some 2D CAD and it handles it quite well.
First move would likely be to try running some of the suggested software to see if it's happy or not.
I use "parallels" and its been pretty stable with other CAD - so my gut feeling is - maybe!


spumco said:


> 2. There are DC servo drives that take step & direction inputs.  That opens up other controller options - most of the ones you've probably been looking at on the internet. Some may take AC input, meaning you wouldnt have to get a bit ac-dc power supply to power the drives.
> 
> Both let you keep the dc servos for handwheel compatibility. Im not going to bother you with part numbers or details,


Bother me!
Kidding aside - everyone has their own likes/preferences.
Jim's been holding a master class - but there have been times where he's had to just be prescriptive - because I either don't have the depth to understand the gives and takes of options - or even if I did - don't have the experience to know what I want yet.
Some other options would be interesting - expand the convo - and sharpen my understanding.
Gives me a chance to ask questions that might enlighten.

Side note:
One thing about entering a new realm.
When you first go in - you don't know who's who.
I mean - you may have a sense of who has depth of knowledge - but you don't know how your profile of needs/likes might match theirs.
That's tough - because it can be expensive to learn - and there are always options to do things well - but differently.
By the time you understand, you've bought your third controller, have a shelf of unused parts, and are swapping to a touch screen...
Just guessing other's have experienced this.

My point is - I welcome the discussion.
You guys are providing incredible learning and value to me.
And I am gonna need that to tackle this hunk of iron.
Fire away!


----------



## spumco

Charlieman22 said:


> Bother me!



You asked for it...  but I'd suggest considering a new 'build' thread once you start accumulating parts and have a fairly serious plan.  Otherwise your/our educational journey in this thread may muddy the waters with interesting tangents...

_Disclaimer: I'm not an expert, I don't know everything.  I'm a hobby guy who's been dabbling in this sort of stuff for a while._

Let's start with the basics like Jim did earlier; forgive me if I'm repeating anything.  To accomplish Computer Numerical Control you need:

*1.* A computer of some sort.  Anything from a single microchip to 'sky's the limit'.  Can be a PC, can be an custom embedded computer. Can be an Arduino, ESP32, whatever.
*1a.* In fact, there are very likely going to be multiple 'computers' in whatever system you build.  The Galil motion controller is a computer, the VFD for your spindle motor is a computer, and there will be another computer (PC) that acts as a user-interface between the Galil and you.
*1b.* To keep it simple, when I refer to a 'computer' I'm referring to the thing you interface directly with, can accept (more-or-less) human-readable commands, and is a very flexible consumer-grade thing. It wasn't built with a single purpose in mind, unlike a motion controller or VFD or 'smart' servo drive, but you can load CNC-dedicated software on it that is designed to communicate with the other computer-like devices in the system.

*2*. Software of some sort. You tell the software what you want and it does the heavy lifting number-crunching and signaling. Can be Windows software, software flashed to an Arduino, can be custom software for a custom computer. 10 million variations. Mach3, KmotionCNC, Jim's custom Galil stuff, UCCNC, Centroid, LinuxCNC, Mach4, the list goes on.

*3.* Stuff that moves in meat-space.  Motors, actuators, solenoids, air cylinders.

*4. *Things that drive those motors in response to signals from the computer.  Computers, as a rule, do not handle the volts/amps required to actuate big motors.  They need an intermediate device that can handle the electrical requirements of the meat-space motors and actuators.

*5.  *Sensors, switches, buttons, etc. Devices that tell the computer (or you) information about what's going on in the real world. The linear encoders Jim's suggested are in this category, as is the big red ESTOP button you're bound to install. Limit switches, pressure transducers, rotary encoders, all of your control buttons/switches. This is where things can get complicated - how much information do you and the computer need to safely accomplish your goals?

*6.* One or more devices that helps 'glue' those five things in to a working system. These can be an ethernet hub, a 'break out board', custom-built boards/devices that have lots of ways to connect the various bits together. All of the bits above usually have different voltages, signal types, signal speed, and amps, not to mention about 10 billion various electrical connector types. Browse through the Mouser or Digi-Key section for 'connectors' some day and you'll ask yourself why electrical component designers want to make the world insanely complicated.

The 'glue' device can be a separate item, or it may be built-in to the PC, motion controller, or other device.  Hobby-level stuff usually uses a separate glue device ("BOB") that the PC & motion controller connect to.  They then use the BOB to signal the drives and receive inputs from the various sensors/switches.  Think of a 3D printer 'board'.  It has a motion controller built-in, and sockets for multiple stepper drives, as well as places to connect limit switches, bed heaters, and other aux devices.  Everything plugs in to that board.  At the other end of the complexity scale, a BOB can be as simple as a board that connects to a PC's printer port and has terminals you can stick wires in.  No chips - just terminals directly connected to the PC.

Applying this to your servo drives... I'm aware of three _fundamental_ methods of commanding the drives to move the motors.  There may be others:

*1. *Digital input (step & direction, A leads B, CW/CCW pulse).  For S&D - an electrical pulse is sent to the drive, and the drive is pre-programmed to move the motor a certain amount per pulse.  A different signal is also sent to indicate the direction of rotation.  The other types of digital input are similar for this simplified explanation.  The thing to keep in mind is that the pulses do not carry information other than their simple presence/absence.  It's like morse code, but with dots and no dashes. The receiving device has to know what to do with the signals ahead of time.

*2.* Analog input (0-10v, +/-10v, 4-20ma, etc.).  In this case a voltage is sent to the drive that represents the amplitude of a command.
*2a.* For really 'dumb' drives - known as amplifiers - the signal represents some percentage of maximum amps the drive is capable of producing.  They just amplify the input signal.  Send it 0v, nothing happens.  Send it +10v and it responds with maximum amps to the motor.  There is no feedback between the motor and the amplifier.
*2.b* Other drives can do some figurin' and convert the analog signal to a speed value, torque value, or position.  Those drives require feedback - either on the motor itself or on the load - to achieve the commanded result.  These drives may be capable of also using digital inputs (see #1), either in addition to, or instead of, the analog signal.

*3. *Last is, for lack of a universal term, _Information_ input.  This very broad category includes anything where you are sending packets of information to a drive/amp that is pre-programmed to know what to do with the info.  Examples: MODBUS, Ethercat, CANbus, ASCII, ad naseum.  Instead of '_move the value of one pulse, do it again, do it again'_, you give the drive the equivalent of a sticky note that says "_Move to position XYZ, at A speed, using accel/decel value of B, and, by the way, report back when you're done and if anything went wrong."_
3a.  This category includes communication methods that are very fast as well as those that are rather slow.  And some drives/devices are capable of talking with each other to synchronize movement across multiple axis of motion; the 'master' computer just issues a "GO HERE" command and the bank of drives talk to each other and figure out how everybody has to respond to meet the target.
3b. This type of communication really cuts back on wiring and electrical complication (i.e. plug an ethernet cable in each drive and yer done), but it increases the complexity in the software/programming side.  You aren't worrying about voltage levels or signal types - you're worrying about communication protocols.
3c. In fact, you will be using this last input type: your PC will be talking to the Galil, Centroid, Kflop, etc. (motion controller) over some sort of communication bus.  Maybe even controlling the VFD through MODBUS, too.

Ok, back to your situation.  Your drives are "2a" really dumb amplifiers.  They take a -10v to +10v signal in, and move the motors using some ratio of output amps to input signal voltage.  -10v = full amps one direction, and vice-versa for +10v.

This method of input is very common in older and/or higher-end motion control systems, but is relatively rare in 'hobby-grade' systems.  Think of all the 3D printers, cheapo laser engravers, desktop paper printers, DIY robots... those are generally all driven with stepper motors whose drives require a digital input.  And the DIY or lower-end stuff that has AC servos also usually take a digital step & direction input.

I suspect the reason for this is that long ago when folks were starting the fiddle with DIY robotics, CNC, and motion control... they were using desktop PC's that were capable of outputting digital signals with no other hardware required.  Converting a computer's digital signal to a stable, precise analog signal isn't child's play _(don't look at the PWM signal, nothing to see here_), so using stepper motors and digital input stepper drives was fairly cheap and easy.  It still is, and if you design a system _fairly _well, it'll work _fairly_ well with stepper motors and no feedback to the computer or software driving the thing around.

*This is Mach3*, and every other CNC software/motion controller that doesn't have any feedback from the mechanism about what's going on. "GO HERE" and the PC & user just assume everything went well.

The next step up is to close the feedback to the drive.  The drive is smart(ish), and knows if the command isn't being followed properly.  This can be a motor encoder, and in some cases a load/position encoder.  If the motor isn't responding to the command properly, the drive can report a fault or - depending on many factors - try to 'catch up' by goosing the motor a bit, or slowing it down.  Whatever is appropriate.

Last step up in the food chain is to close the feedback to the actual motion controller, whether that's the PC or a dedicated device like the Galil or Kflop.  If the motion controller knows how all the motors/actuators are operating - in real time - it can adjust everything on the fly to achieve the precision required of the system.

*This is Jim's plan. * You will have a PC with some sort of CNC software. That software will, via an ethernet cable, tell the motion controller (Galil) what it wants done. The motion controller will then plan the 'trajectory' of all the axes, figure out how each motor or actuator must move, and output signals to the various drives to achieve the desired position of each axis, at the appropriate speed and acceleration/decel rate. The motion controller will be receiving precise location data continuously and it uses that to calculate/recalculate the signals being sent to the motors.

The PC software may get information back from the motion controller, but likely it will not.  The PC may be getting info from the various other sensors (limit switches, air pressure sensors, etc.) and uses that to issue/change commands to the motion controller.  This last part depends on the software, as well as what sensors and 'glue' device being used.

For your particular situation, here's a start - some DC servo drives I mentioned earlier:

https://www.machdrives.com/bra.aspx

http://shop.cncdrive.com/index.php?productID=509

https://www.copleycontrols.com/en/products/xel-230-18/

I'm not necessarily advocating those particular items, but they're examples of drives that can use a signal input type different than the ones you have and drive a brushed DC servo.

The first and third can take _both_ motor encoder and load encoder signals in... meaning the drives will correct for any position deviation due to mechanical backlash in the system. Nice, but if your motion controller is capable of receiving load encoder info, is it necessary?

The last one (Copley) is powered directly by AC line voltage, while the first two require DC to power them (need a transformer).  And the Copley Xenus can take multiple input types (digital, analog, information), drive multiple motor types (DC brushed or 3-phase brushless), and act as a stand-alone motion controller unconnected to anything else.
Unsurprisingly it's rather expensive.

That's enough for now.  Digest it, and while you're rummaging around on the internet looking at mysterious electrical devices and software see if you can mentally categorize what that 'thing' is and how it fits in to the big-picture I've outlined above.

-Ralph


----------



## spumco

Just spit-balling, but...



JimDawson said:


> #6 Servo drive power transformer. Remove, not needed.


I could be wrong, but it looks like a line reactor with the three coils.



JimDawson said:


> #5 240/120 VAC Control Transformer. Keep


I think this is the servo drive transformer.  I think that huge toroid feeds AC through the two black wires to #8, where it's rectified and smoothed with what looks like a gigantic cap to the right of the brown box.  That transformer must weigh 40lbs.



JimDawson said:


> #7A Small transformer at bottom. Not sure what it's for, need further information.


I think this is the 120vac control transformer.


----------



## Charlieman22

Ralph.
Excellent.
Very good of you to have taken the time to walk me through that.
Some great color added that is super helpful for my depth of understanding.
You probably also just saved Jim 45 minutes of his life he would never get back - typing additional explanations to me.
Which should cut down his investment in this to just "unreasonably large" rather than -  "you must be kidding me".
 

I literally got just to the end before you typed something I couldn't follow.


spumco said:


> I'm not necessarily advocating those particular items, but they're examples of drives that can use a signal input type different than the ones you have and drive a brushed DC servo.


when you say "signal input type different than the ones you have", which "ones" are you referring to?


----------



## JimDawson

spumco said:


> Just spit-balling, but...
> I could be wrong, but it looks like a line reactor with the three coils.



If you blow the picture up and turn it upside down you can read some of the data plate.  Looks like it is a delta-delta wired transformer with a 165V output.  Having said that, it could be a buck transformer.  The servo motors are rated at 172VDC.   But the voltage I can read on that device (165V) is a bit confusing because 165 * 1.414 = 233 VDC when rectified.  But there are multiple taps on that device and I can't read the data for them.




> I think this is the servo drive transformer.  I think that huge toroid feeds AC through the two black wires to #8, where it's rectified and smoothed with what looks like a gigantic cap to the right of the brown box.  That transformer must weigh 40lbs.



The wire color and numbers on that transformer don't match up with what I see going into the drive, which is fed with 3 black wires, labeled 14, 15, 16, same as the device above..  Best guess is this is computer power.



> I think this is the 120vac control transformer.



Maybe.


----------



## JimDawson

spumco said:


> You asked for it...  but I'd suggest considering a new 'build' thread once you start accumulating parts and have a fairly serious plan.  Otherwise your/our educational journey in this thread may muddy the waters with interesting tangents...
> 
> _Disclaimer: I'm not an expert, I don't know everything.  I'm a hobby guy who's been dabbling in this sort of stuff for a while._
> 
> Let's start with the basics like Jim did earlier; forgive me if I'm repeating anything.  To accomplish Computer Numerical Control you need:
> 
> *1.* A computer of some sort.  Anything from a single microchip to 'sky's the limit'.  Can be a PC, can be an custom embedded computer. Can be an Arduino, ESP32, whatever.
> *1a.* In fact, there are very likely going to be multiple 'computers' in whatever system you build.  The Galil motion controller is a computer, the VFD for your spindle motor is a computer, and there will be another computer (PC) that acts as a user-interface between the Galil and you.
> *1b.* To keep it simple, when I refer to a 'computer' I'm referring to the thing you interface directly with, can accept (more-or-less) human-readable commands, and is a very flexible consumer-grade thing. It wasn't built with a single purpose in mind, unlike a motion controller or VFD or 'smart' servo drive, but you can load CNC-dedicated software on it that is designed to communicate with the other computer-like devices in the system.
> 
> *2*. Software of some sort. You tell the software what you want and it does the heavy lifting number-crunching and signaling. Can be Windows software, software flashed to an Arduino, can be custom software for a custom computer. 10 million variations. Mach3, KmotionCNC, Jim's custom Galil stuff, UCCNC, Centroid, LinuxCNC, Mach4, the list goes on.
> 
> *3.* Stuff that moves in meat-space.  Motors, actuators, solenoids, air cylinders.
> 
> *4. *Things that drive those motors in response to signals from the computer.  Computers, as a rule, do not handle the volts/amps required to actuate big motors.  They need an intermediate device that can handle the electrical requirements of the meat-space motors and actuators.
> 
> *5.  *Sensors, switches, buttons, etc. Devices that tell the computer (or you) information about what's going on in the real world. The linear encoders Jim's suggested are in this category, as is the big red ESTOP button you're bound to install. Limit switches, pressure transducers, rotary encoders, all of your control buttons/switches. This is where things can get complicated - how much information do you and the computer need to safely accomplish your goals?
> 
> *6.* One or more devices that helps 'glue' those five things in to a working system. These can be an ethernet hub, a 'break out board', custom-built boards/devices that have lots of ways to connect the various bits together. All of the bits above usually have different voltages, signal types, signal speed, and amps, not to mention about 10 billion various electrical connector types. Browse through the Mouser or Digi-Key section for 'connectors' some day and you'll ask yourself why electrical component designers want to make the world insanely complicated.
> 
> The 'glue' device can be a separate item, or it may be built-in to the PC, motion controller, or other device.  Hobby-level stuff usually uses a separate glue device ("BOB") that the PC & motion controller connect to.  They then use the BOB to signal the drives and receive inputs from the various sensors/switches.  Think of a 3D printer 'board'.  It has a motion controller built-in, and sockets for multiple stepper drives, as well as places to connect limit switches, bed heaters, and other aux devices.  Everything plugs in to that board.  At the other end of the complexity scale, a BOB can be as simple as a board that connects to a PC's printer port and has terminals you can stick wires in.  No chips - just terminals directly connected to the PC.
> 
> Applying this to your servo drives... I'm aware of three _fundamental_ methods of commanding the drives to move the motors.  There may be others:
> 
> *1. *Digital input (step & direction, A leads B, CW/CCW pulse).  For S&D - an electrical pulse is sent to the drive, and the drive is pre-programmed to move the motor a certain amount per pulse.  A different signal is also sent to indicate the direction of rotation.  The other types of digital input are similar for this simplified explanation.  The thing to keep in mind is that the pulses do not carry information other than their simple presence/absence.  It's like morse code, but with dots and no dashes. The receiving device has to know what to do with the signals ahead of time.
> 
> *2.* Analog input (0-10v, +/-10v, 4-20ma, etc.).  In this case a voltage is sent to the drive that represents the amplitude of a command.
> *2a.* For really 'dumb' drives - known as amplifiers - the signal represents some percentage of maximum amps the drive is capable of producing.  They just amplify the input signal.  Send it 0v, nothing happens.  Send it +10v and it responds with maximum amps to the motor.  There is no feedback between the motor and the amplifier.
> *2.b* Other drives can do some figurin' and convert the analog signal to a speed value, torque value, or position.  Those drives require feedback - either on the motor itself or on the load - to achieve the commanded result.  These drives may be capable of also using digital inputs (see #1), either in addition to, or instead of, the analog signal.
> 
> *3. *Last is, for lack of a universal term, _Information_ input.  This very broad category includes anything where you are sending packets of information to a drive/amp that is pre-programmed to know what to do with the info.  Examples: MODBUS, Ethercat, CANbus, ASCII, ad naseum.  Instead of '_move the value of one pulse, do it again, do it again'_, you give the drive the equivalent of a sticky note that says "_Move to position XYZ, at A speed, using accel/decel value of B, and, by the way, report back when you're done and if anything went wrong."_
> 3a.  This category includes communication methods that are very fast as well as those that are rather slow.  And some drives/devices are capable of talking with each other to synchronize movement across multiple axis of motion; the 'master' computer just issues a "GO HERE" command and the bank of drives talk to each other and figure out how everybody has to respond to meet the target.
> 3b. This type of communication really cuts back on wiring and electrical complication (i.e. plug an ethernet cable in each drive and yer done), but it increases the complexity in the software/programming side.  You aren't worrying about voltage levels or signal types - you're worrying about communication protocols.
> 3c. In fact, you will be using this last input type: your PC will be talking to the Galil, Centroid, Kflop, etc. (motion controller) over some sort of communication bus.  Maybe even controlling the VFD through MODBUS, too.
> 
> Ok, back to your situation.  Your drives are "2a" really dumb amplifiers.  They take a -10v to +10v signal in, and move the motors using some ratio of output amps to input signal voltage.  -10v = full amps one direction, and vice-versa for +10v.
> 
> This method of input is very common in older and/or higher-end motion control systems, but is relatively rare in 'hobby-grade' systems.  Think of all the 3D printers, cheapo laser engravers, desktop paper printers, DIY robots... those are generally all driven with stepper motors whose drives require a digital input.  And the DIY or lower-end stuff that has AC servos also usually take a digital step & direction input.
> 
> I suspect the reason for this is that long ago when folks were starting the fiddle with DIY robotics, CNC, and motion control... they were using desktop PC's that were capable of outputting digital signals with no other hardware required.  Converting a computer's digital signal to a stable, precise analog signal isn't child's play _(don't look at the PWM signal, nothing to see here_), so using stepper motors and digital input stepper drives was fairly cheap and easy.  It still is, and if you design a system _fairly _well, it'll work _fairly_ well with stepper motors and no feedback to the computer or software driving the thing around.
> 
> *This is Mach3*, and every other CNC software/motion controller that doesn't have any feedback from the mechanism about what's going on. "GO HERE" and the PC & user just assume everything went well.
> 
> The next step up is to close the feedback to the drive.  The drive is smart(ish), and knows if the command isn't being followed properly.  This can be a motor encoder, and in some cases a load/position encoder.  If the motor isn't responding to the command properly, the drive can report a fault or - depending on many factors - try to 'catch up' by goosing the motor a bit, or slowing it down.  Whatever is appropriate.
> 
> Last step up in the food chain is to close the feedback to the actual motion controller, whether that's the PC or a dedicated device like the Galil or Kflop.  If the motion controller knows how all the motors/actuators are operating - in real time - it can adjust everything on the fly to achieve the precision required of the system.
> 
> *This is Jim's plan. * You will have a PC with some sort of CNC software. That software will, via an ethernet cable, tell the motion controller (Galil) what it wants done. The motion controller will then plan the 'trajectory' of all the axes, figure out how each motor or actuator must move, and output signals to the various drives to achieve the desired position of each axis, at the appropriate speed and acceleration/decel rate. The motion controller will be receiving precise location data continuously and it uses that to calculate/recalculate the signals being sent to the motors.
> 
> The PC software may get information back from the motion controller, but likely it will not.  The PC may be getting info from the various other sensors (limit switches, air pressure sensors, etc.) and uses that to issue/change commands to the motion controller.  This last part depends on the software, as well as what sensors and 'glue' device being used.
> 
> For your particular situation, here's a start - some DC servo drives I mentioned earlier:
> 
> https://www.machdrives.com/bra.aspx
> 
> http://shop.cncdrive.com/index.php?productID=509
> 
> https://www.copleycontrols.com/en/products/xel-230-18/
> 
> I'm not necessarily advocating those particular items, but they're examples of drives that can use a signal input type different than the ones you have and drive a brushed DC servo.
> 
> The first and third can take _both_ motor encoder and load encoder signals in... meaning the drives will correct for any position deviation due to mechanical backlash in the system. Nice, but if your motion controller is capable of receiving load encoder info, is it necessary?
> 
> The last one (Copley) is powered directly by AC line voltage, while the first two require DC to power them (need a transformer).  And the Copley Xenus can take multiple input types (digital, analog, information), drive multiple motor types (DC brushed or 3-phase brushless), and act as a stand-alone motion controller unconnected to anything else.
> Unsurprisingly it's rather expensive.
> 
> That's enough for now.  Digest it, and while you're rummaging around on the internet looking at mysterious electrical devices and software see if you can mentally categorize what that 'thing' is and how it fits in to the big-picture I've outlined above.
> 
> -Ralph



Really nice writeup Ralph, great explanations.


----------



## spumco

Charlieman22 said:


> when you say "signal input type different than the ones you have", which "ones" are you referring to?



The drives in the Webb take analog signal.  -10vdc to +10vdc = full output (amps) one direction to the other direction.

Two of the drives I linked to take a digital input (step and direction) signal.  Low-voltage pulses, and the drive is programmed to move the motor a certain amount per pulse.

The last drive can accept analog signals just like yours, digital signals (many variations), and can also be controlled via the 'information input' type of signal.


----------



## spumco

JimDawson said:


> The wire color and numbers on that transformer don't match up with what I see going into the drive, which is fed with 3 black wires, labeled 14, 15, 16, same as the device above.. Best guess is this is computer power.



Ah-hah!

I just spotted the third wire going in to the brown box mostly hidden behind the big "8".  Good catch.



JimDawson said:


> Best guess is this is computer power.


I feel dumb now.  I guess that thing is old enough to need a big honkin' power supply for the CRT monitor and power-hungry old-school computer.


----------



## Charlieman22

Ok - fist a little house cleaning.
Plan is to start a new thread as I move to the more general build.
Does it go in "all about machine restoration & way scraping", or "General..."?
Either way - hope you guys will come along for the ride when I move.
Watching videos of guys taking apart machines that are half the weight.
I'm in for some work...

Now - back to this pre-planning/ base of understanding thread:
Lemme see if I have this right - and clarify a few things at the end.

Jim proposed closed loop.  I like.
Basic components - tho some may be all in one:
My servos - brushed DC
Magnetic readers - 4 of them*
These feed back to a BOB
Servo drives* that can run my DC servos (plugged in to BOB) - this is the Galil unit or Copeley or the like
PC that is part of the machine itself - could be built in to BOB but think this would be separate board
Screen and keyboard
Some interface buttons/control panel of some kind
A VFD
Perhaps some DC power supplies
Main disconnect & fuses 
Software to run the machine
Software to create the parts on my existing computer

So simple!  Why didnt you guys just say so?  

Ok - now a couple questions/ clarifications so I can get some idea of budget for above:
1.  When I first posted the pic of the box with numbers on sections - #2 was Servo Drives.("need some slight modification").  Would the  Galil or Copeley mean these would get tossed rather than kept? (did this plan change?)
2.  Jim noted 4 magnetic readers.  Are we going to put the DRO on the quill feed as well as the Z?  
3.  When I look at the Galil or Copeley style servo drives - am I going to be shopping for 1 for all my servos or 1 for each servo? (and is that then 3 or 4 if one each?)
4.  Jim - would I be using a BOB?  If yes - could you flag an example so I get a sense of cost.
5.  For phase I: manual operation, Is the VFD basically going to be wired directly to feed power to my spindle motor and DRO - all other stuff in the box will be dormant in this phase?  This goes to how much stuff I might rip off to start with.

With above - I can get a sense of Phase I and Phase II major component costs/ configurations.
Can't wait to pick this thing up!
-CM


----------



## spumco

Charlieman22 said:


> Servo drives* that can run my DC servos (plugged in to BOB) - this is the Galil unit or Copeley or the like



The servo drives stay, with some slight modification according to Jim.  Those are outside my ken, so you'll have to rely on Jim for details.

The remainder of the setup will depend on exactly which Galil you get, or other motion controller.  Maybe a diagram will help.

Green arrows are information or signals.  Red is power.




The "maybe" depends on what voltage the magnetic scales (encoders) use.  The 24vdc also depends on what various sensors you use, and what the Galil needs.  In this case I've drawn the motion controller/BOB as one 'box', but depending on what motion controller you use it may be a separate device.

All three of the devices I linked to earlier fall in to the "SERVO DRIVE" category, not the motion controller or BOB category.  I confused you when I stated that the Copley can act as all three... it can, but not in your case.


----------



## spumco

Charlieman22 said:


> Is the VFD basically going to be wired directly to feed power to my spindle motor


Yes.  The VFD gets wired to line power in and the motor regardless of who controlls it - you (manual) or the Galil (CNC).  So power for the VFD looks like:

AC in > master disconnect switch > fuse/breaker > contactor > VFD > motor

Once you have that, you can turn the spindle motor on/off to your heart's content with no CNC stuff around.  When you do the CNC stuff, you simply add some wires to the VFD and program it to respond to those wires instead of the VFD's keypad.


----------



## spumco

Charlieman22 said:


> With above - I can get a sense of Phase I and Phase II major component costs/ configurations.


You'll get a sense of how much it costs when you're finished.  Not before.


----------



## Charlieman22

spumco said:


> All three of the devices I linked to earlier fall in to the "SERVO DRIVE" category, not the motion controller or BOB category.


So these would be a config that would require addition of a BOB - where the Galil would be an all in one, and a single Galil like the 4140 would be the motion control for all of my servos.  
Looks like Galil holds tight distribution rules.
I'll contact to get pricing info.

Ralf - For one's falling into Servo Drive category - requiring BOB - would I need 1 Drive per servo or does 1 Drive box handle multiple servos also?  That part still a bit fuzzy for me.


spumco said:


> Maybe a diagram will help.
> 
> Green arrows are information or signals. Red is power.


Thanks - yes.


spumco said:


> AC in > master disconnect switch > fuse/breaker > contactor > VFD > motor


Got it!  Thanks!  This is the stripped down version.  My inclination is to consider finding a smaller box to put on the side or back to keep things tidy until I figure out how I will configure the entire thing.  


Charlieman22 said:


> 1. When I first posted the pic of the box with numbers on sections - #2 was Servo Drives.("need some slight modification"). Would the Galil or Copeley mean these would get tossed rather than kept? (did this plan change?)


Not that it's make or break - but still curious about this.  Jim - did your thinking about best config for me evolve making these obsolete?

Lotta time put in by you guys on this.
I'm now armed and unquestionably dangerous - most likely to myself.
I will craft my build thread.
Current working title:  Beauty in The Beast.
 
-CM


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## JimDawson

Ralph's description/diagram above is beautiful. Shows all of the components required to make a professional CNC system and how they interact with each other.

So the plan at this point:
Closed loop system, loop closed at the controller, no real point in discussing the other options.
The brain of the system is the motion controller.  This could be Galil, Dynomotion, Centroid, or Mesa.
PC running the CNC software and providing the user interface.  In this case would be connected to the controller via Ethernet or USB cable.
One drive required for each axis motor (3), compatible drives currently exist in the machine.  Ignore the fact that Galil does have optional built in servo drives available.  
Position feedback devices (encoders) can be linear or rotary.  Recommend linear magnetic. One for each powered axis (X, Y, Z (quill)), plus the knee. (4)
Appropriate power supplies to run everything.

If you are going to go with a Galil, a DMC-4040 4 axis unit from eBay would be my choice.  The last DMC-4040 I bought was $112, retail price is $2295 for the base unit from Galil.  A fully loaded DMC-4040 with 4 built in 160V, 750W drives is $3530.  Stay away from the 41x3 units.

Just a bit of clarification, a BOB is just simply a *B*reak *O*ut *B*oard, something to connect wires to (normally with screw terminals), since it would be difficult to solder wires directly to the controller chip.  The controller manufactures bring out the connections on the controller board to some type of plug connectors or screw terminals.  Galil for instance uses D-sub connectors on their units, there are many options available to break those out to screw terminals.

An example: https://www.amazon.com/D-SUB-Terminal-Breakout-Connector-Screws/dp/B0779WGQN4


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## Charlieman22

Well - it's appropriate that Jim made the final post in this - for the time being.
And an excellent last bit of info it is.
Thank you.



JimDawson said:


> If you are going to go with a Galil, a DMC-4040 4 axis unit from eBay would be my choice. The last DMC-4040 I bought was $112, retail price is $2295 for the base unit from Galil. A fully loaded DMC-4040 with 4 built in 160V, 750W drives is $3530. Stay away from the 41x3 units.


I will set alerts to let me know if one pops up while I work on the physical machine in the mean time.  Let's see if a 4040 shows up.  This is my target.

New thread on the heavy lifting and rehab of the physical machine starts here:








						Beauty in The Beast: Webb 5BVK Barn Find/Conversion
					

New to forum & machining generally. Working on two stroke motors drove my initial interest to learn. Started searching for a Bridgeport... Next thing I knew - I was standing outside a barn, 2 hours from my house, looking at a 4K lb non working CNC Webb knee mill.  More about how I got there and...




					www.hobby-machinist.com
				




Thanks to all who helped me get launched to this point.
Come join the group helping or throwing tomatoes at me over at the other post!


-CM


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## spumco

JimDawson said:


> Ralph's description/diagram above is beautiful.


[blush]

To expand on Jim's description of the BOB...  remember that the diagram I drew identifies various _functions_ - not just specific components.  In some systems those functions are combined in to a single device; in others the functions are split up.  I drew that one as it was as close as I could get to a Galil-based system (not having used one before).

The big dividing point (in my mind) is what device is planning the trajectory of each axis?  The 'thing' that does the trajectory planning is not always as I've drawn it; the lines blur depending on what software or hardware you're using.  That's why I labeled the Galil as 'motion controller', with the BOB function as a sub-set within the box.

Here's a different example with LInuxCNC and a Mesa setup for analog servos.  LinuxCNC is the trajectory planner/motion controller, but the main Mesa board is more than just a breakout board.  It takes commands from the PC and generates very precise signals to the drives, as well as acting as a 'hub' for other components (like encoders, general sensors, etc.)



Last is the most simplistic system.  PC with Mach3, connected to the various stuff through a 'dumb' break out board like Jim described:



This one has no feedback from the drives to Mach3.  Mach3 has no idea what's going on, except for the various limit switches and similar.   No encoders, no analog servo drives.  Just stepper motors.

There are many, many different configurations than the three I've drawn out for you, but hopefully you get the gist of general architecture.

-Ralph


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