# CNC daydreaming



## rabler (Oct 21, 2021)

I'm daydreaming of building a small CNC mill some day.  And probably a plasma cutter too, although I could see myself buying one of those, possibly even used.  But the CNC mill is likely first.

This would be at least a year down the road before actually doing.  I've got a new shop that's schedule to get framed up in January, and it'll keep me busy for quite a few months (and keep my budget slim) as I'll need to finish it out with insulation, electric, etc.   So in part I'm just killing time daydreaming until they start building the shop. 

I'm inclined toward starting with something like a PM-940V (that's my current thought), hardened ways, get the Arizona Video ball screws and servo motors, then build it up myself from there.  I've read a few threads discussing that.  I'm fairly comfortable with messing with electronics.  I will probably go with linuxcnc.  I'm an old Unix/linux hack going back to the early 80's.  I have looked at Centroid Acorn too.  I'm still kicking around options so none of this is set in stone.  I've looked at Tormach, and while the DIY aproach isn't all that much cheaper, I'm just more inclined to do it myself.

I don't currently use any CAD environment for my hobby work.  There was a time in my professional career many years ago where I was heavy into AutoCad, hell I've even done a bit of VLSI layout.  But the pendulum swing on retirement was to get away from working in front of a monitor. 

Right now one of my biggest challenges is internet bandwidth.  I'm using HughesNet satellite service.  This means YouTube, while a good resource, is pretty much out of the questions (except if I have insomnia, 2am - 8am doesn't count against the usual quota).  It also hampers using any internet CAD tools, like Fusion360.  I have a deposit in with Starlink, so hopefully that situation improves some in the very near future.

So what are some good learning resources for doing a CNC mill conversion?  What advice do those of you with hands on experience doing this wish you would have heard before starting?


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## Ulma Doctor (Oct 22, 2021)

i too, am seriously considering the jump to CNC- or at least jumping into the unknown as far as learning about programming.
i have seen a few videos and i have a basic grasp of what is happening while the program is carried out
3D printing has already happened on my end,
i imagine reductive g-code may be generated by similar programs to the additive slicer g-code

i'm looking at GRBL control cnc mini routers as a starting point , but i'm not sure if the really cheap ones are a waste of time or to get a more advanced starting unit


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## Karl_T (Oct 22, 2021)

I have refit a half dozen mills and lathes over the years...

IF you have the room, by far the best deal is a dead CNC mill. The iron is nearly always just fine or only needing minor work. Should be able to find one for far less than you would spend any other way. For example, my son has a beautiful Tree knee mill with servos - $2K.  You need to kick the weeds but several of these dead CNC mills are around.


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## ArmyDoc (Oct 22, 2021)

Wow.  The similarities between you and me are scarily similar. Are you sure your not me from some kind of alternate universe?

Good luck with the shop.  I started my shop last year.  It can be a slow process and life frequently gets in the way, but it's very exciting. What size shop are you building?

What machines do you have now?  My understanding is sometimes even if you go with a kit, the parts can nee refinement.  

What size machine do you want/need?  Travels, particularly z axis can be limiting on smaller machines.  

For CAD, I had been using fusion 360, but they've limited it unless you shell out for the whole price..  I'm looking at solid works for maker's ($100) or free advertising now. 

Have you looked into starling? Put my $100 deposit down,  but God knows when they'll actually deliver... they say it's going out of beta this month.

Good luck and keep us posted!


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## ArmyDoc (Oct 22, 2021)

ArmyDoc said:


> For CAD, I had been using fusion 360, but they've limited it unless you shell out for the whole price..  I'm looking at solid works for maker's ($100) or free advertising now.



Your post prompted me to quit thinking about it and do something.  So, thanks!  

I just ordered (well, started the process anyhow) solidworks student edition, which is available to military veterans for $20/year.  It's available on a DVD rather than download which is critical for me because of internet access issues.  Uploaded my DD214 and they should get back to me in the next two days with a link to place the order/make mayment.


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## matthewsx (Oct 22, 2021)

We've seen your lathe....

I can't imagine anything less than a full size VMC would be suitable in the new shop you're building. Haas, Fadal, Mazak, etc.

I have a small CNC mill/drill project and I suspect that once you buy a new PM machine and get all the pieces to convert it you will be very close to, or exceeding the price of a full blown VMC. Decent used one can be had which need updated controllers. knee (Bridgeport) type often go for even less $$.

@JimDawson has been an awesome resource for folks on here doing retrofits.

Just make sure when you order power for the new shop you get a lot....

John


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## rabler (Oct 22, 2021)

ArmyDoc said:


> Wow.  The similarities between you and me are scarily similar. Are you sure your not me from some kind of alternate universe?
> 
> Good luck with the shop.  I started my shop last year.  It can be a slow process and life frequently gets in the way, but it's very exciting. What size shop are you building?
> 
> ...


Well, I did live in Georgia for quite a few years.
40x56x12 shop for the machining and fab/welding.  The woodworking stuff (quite a bit) will stay in the current 30x30 shop, along with my electrical stuff and my wife's refinishing bench.  All the machines I have now are full manual, a 26x50 Monarch lathe, a K&T 3K vertical mill are the big 3phase machines currently over at the garage by the barns, a Grizzly G757Z mill and Monarch CK (12x30) lathe are single phase currently in the woodshop.  I have two surface grinders, both of which need to be rebuilt before use.

I think I can still get an academic license to solidworks.  If that's the case I will jump on that.

Starling?  Do you mean SpaceX's starlink?  If so, yes I'm on the waitinglist.



matthewsx said:


> I have a small CNC mill/drill project and I suspect that once you buy a new PM machine and get all the pieces to convert it you will be very close to, or exceeding the price of a full blown VMC. Decent used one can be had which need updated controllers. knee (Bridgeport) type often go for even less $$.
> 
> @JimDawson has been an awesome resource for folks on here doing retrofits.
> 
> Just make sure when you order power for the new shop you get a lot....



I hadn't thought of the updating approach.  A retrofit would be something I could certianly do.

As far as power, the house currently has a 200A feed which includes the woodshop.  There is a separate 200A feed for the barns which is a major reason the RPC, K&T & big Monarch are over there.  The new shop will initially be a 200A feed off the house service disconnet, but I'm setting it up so that it would be relatively easy to put in a 400A service split to 200A for the house and woodshop, and another 200A feed to the metalshop.


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## rabler (Oct 22, 2021)

Here is my thread on building a new shop.


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## matthewsx (Oct 22, 2021)

It has been said on here before, "you can't add iron"

Given the space, and your background I think you'll be well served looking for a used but decent condition industrial machine. I think what happens is a shop will put something into production only to have technology or demand change on them and they'll end up with an "orphan" machine. When you're busy making money it doesn't make sense to retrofit old stuff, just get something else and keep the parts rolling out.

Since you have time on your side do some research, figure out power requirements and what machines are good candidates for a retrofit, and start your search. 

For inspiration:









						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
				




John


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## JimDawson (Oct 22, 2021)

rabler said:


> So what are some good learning resources for doing a CNC mill conversion? What advice do those of you with hands on experience doing this wish you would have heard before starting?


There are some good threads on Hobby Machinist and CNC Zone of machine conversions.  Mostly small equipment.

But I'm another vote for starting with a commercial built CNC machine.  All of the expensive and hard mechanical work is already done and all you have to do is hang the new controller/motors of your choice on the machine and press go to make parts.

Personally if I only had one mill in the shop it would be a BP or clone knee mill with both manual and CNC capability.  These machines pop up on eBay and Craigslist occasionally, normally around mid-80's vintage.  Nothing wrong with getting a 35 year old machine if it is in reasonably good mechanical shape.  For more serious production work, you need a VMC with auto tool changer.  These can be found, with dead controllers, for scrap price or less.  I saw one for free the other day.  Normally if the old machines are lubricated properly through their life, they just don't wear out.  My 35 year old Hardinge CNC lathe runs every day and will hold +/- 0.0002'' all day long.


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## rabler (Oct 22, 2021)

JimDawson said:


> But I'm another vote for starting with a commercial built CNC machine. All of the expensive and hard mechanical work is already done and all you have to do is hang the new controller/motors of your choice on the machine and press go to make parts.
> 
> Personally if I only had one mill in the shop it would be a BP or clone knee mill with both manual and CNC capability. These machines pop up on eBay and Craigslist occasionally, normally around mid-80's vintage. Nothing wrong with getting a 35 year old machine if it is in reasonably good mechanical shape. For more serious production work, you need a VMC with auto tool changer. These can be found, with dead controllers, for scrap price or less. I saw one for free the other day. Normally if the old machines are lubricated properly through their life, they just don't wear out. My 35 year old Hardinge CNC lathe runs every day and will hold +/- 0.0002'' all day long.



Good input from everyone!  Glad I posted this, kind of felt like it was a aimless thread but I'm getting some great ideas.  Thanks you everyone!!

I've certainly seen VMCs go for fairly cheap recently at auction.  Chicago and much of Ohio are within range and I have a 10 ton trailer.
I'm strictly a hobbyist, and have no desire toward production.  But I already have a couple machines that are in the 4-5 ton size range, so big is not out of the question.   I don't foresee getting rid of my manual equipment, so I'd lean toward a dedicated CNC machine rather than a mixed machine.

How much different is it to take a commercial VMC and rebuild the electronic than building around a knee mill?  Any things to particularly look for or look out for on either one?  Or particular models to look for or avoid?    All the pictures of VMC's look like cabinets, so I really have no idea how similar or different they are from manual machines.


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## Karl_T (Oct 22, 2021)

The big question here is do you want a tool changer?  For a first timer, making this work can be quite the challenge. And its not going to happen with the inexpensive hobby controls unless you are a wizard with interfacing a PLC.

The cabinet is just an enclosure for flood coolant and chips to not get out in the room. Nice if you got the space.

My two cents you won't go wrong with a good heavy duty knee mill with dead control. Look for box ways and taper 30 or taper 40 tooling - this is WAY MORE RIGID than an R8 dovetail way machine. These should come with an air or hydraulic tool release, makes hand tool changes real quick.

I wore out my excello with these features and then rebuild a Vectrax. there is a thread on this website for the rebuild.


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## JimDawson (Oct 22, 2021)

rabler said:


> How much different is it to take a commercial VMC and rebuild the electronic than building around a knee mill? Any things to particularly look for or look out for on either one? Or particular models to look for or avoid? All the pictures of VMC's look like cabinets, so I really have no idea how similar or different they are from manual machines.



There is really very little difference from the controls end.  Just a bit more wiring for the additional hardware.  They normally come equipped with an automatic tool changer (ATC).  16''x20'' and 20''x40'' are common sizes in the smaller machines (<10K lbs.)  Normal spindle power for the smaller machines is 7.5 to 10 HP, with maximum spindle speeds in the 5K to 10K RPM range. 

EDIT:  I should note here that an ATC does not mean that you have to use it, you can also do manual tool changes with a button push to release and install the tool in the spindle.

There is a huge difference in the VMC machine frame compared to a knee mill.  The VMCs are bed mills, a much more robust arrangement.  All of the Z axis movement on the column.  These machines are engineered and built for heavy production use.


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## Reddinr (Oct 22, 2021)

Does Solidworks "Maker / 3dexperience" version include a way to post process for making g-code?  Their marketing videos are frustratingly slim on information about what you get and what you don't

Thanks, R


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## rabler (Oct 22, 2021)

Karl_T said:


> My two cents you won't go wrong with a good heavy duty knee mill with dead control. Look for box ways and taper 30 or taper 40 tooling - this is WAY MORE RIGID than an R8 dovetail way machine.


I don't know what "dead control" means?  I have a K&T 3K, that for it's age is in pretty good condition in terms of table/bed wear.  




JimDawson said:


> There is a huge difference in the VMC machine frame compared to a knee mill. The VMCs are bed mills, a much more robust arrangement. All of the Z axis movement on the column. These machines are engineered and built for heavy production use.



I think rebuilding the electronics in a VMC is going to be the plan.  Now I just need to find which models are of an appropriate size.  Some of them are ridiculously large.  The 7.5-10 HP range fits my power/weight budget.  I'm pretty sure I'll have room in the new shop, even with thoughts of a few other toys.  I think the ATC is something I could start with not using and then eventually incorporate into the electronics.


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## coherent (Oct 22, 2021)

rabler said:


> I'm daydreaming of building a small CNC mill some day.  And probably a plasma cutter too, although I could see myself buying one of those, possibly even used.  But the CNC mill is likely first.
> 
> This would be at least a year down the road before actually doing.  I've got a new shop that's schedule to get framed up in January, and it'll keep me busy for quite a few months (and keep my budget slim) as I'll need to finish it out with insulation, electric, etc.   So in part I'm just killing time daydreaming until they start building the shop.
> 
> ...



I'm not sure what your internet speed has to with wanting to get into CNC but maybe I missed something. If you haven't yet, check into Starlink internet and see if it's available in your area yet. I'm also in a limited options rural location and the best I could get was 15mb or less from Suddenlink (which is the worst ISP and customer service imaginable) . Signed up for Starlink and now average 150-200mb down, 15-25mb up and no monthly limits for 99 a month. Best move I ever made.

It sounds like you are on the right track decision wise as far and getting a CNC mill.
I started in CNC nearly 20 years ago. Things have come a long long way for the budget and "do it yourselfer". Read, read and read some more. Lots of online information. The more you read, the more it will all come together for you. Once you actually get into a build and then use the machine a bit, most of the mystique will go away and it's all pretty simple. If you want a CNC mill, first find a model that lots of others have converted (sounds like you already have) and and buy a new or used mill in the size and price range you want. You'll learn much much more than buying a new cnc mill or a  machine that someone else has converted. I think the CAD CAM side of stuff has the biggest learning curve, but there is no reason you can't start on that now and be ahead of the learning curve before you actually have a machine.  I've build a number of machines including CNC Laser cutters, CNC mills, CNC routers and 3 or 4 CNC Plasma cutters and other than some minor hardware and cut file programming differences CNC is CNC no matter the machine.  I have a couple of 3d printers and they do differ in software and CAD modeling to some extent but most general techinques and CAD/CAM skills are the same. 
If you can find a fellow forum member or a neighbor who has a CNC router, mill or plasma cutter a little time watching or having them explain and use the machine will go a long way toward simplifying things and helping you decide on the route you want to take and machine you want for your purposes. Tons of videos out there on specific machines and conversions.
Good luck!


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## rabler (Oct 22, 2021)

coherent said:


> I'm not sure what your internet speed has to with wanting to get into CNC but maybe I missed something. If you haven't yet, check into Starlink internet and see if it's available in your area yet. I'm also in a limited options rural location and the best I could get was 15mb or less from Suddenlink (which is the worst ISP and customer service imaginable) . Signed up for Starlink and now average 150-200mb down, 15-25mb up and no monthly limits for 99 a month. Best move I ever made.



Glad to hear that you're getting good performance from Starlink.  As I mentioned earlier I'm on the waiting list.  HughesNet limits you to some minimal data per month at a fairly modest bandwdith, it makes streaming any internet video prohibitive.  The hobbyist version of Fusion360 uses cloud storage, so slow internet makes it somewhat clumsy.


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## JimDawson (Oct 22, 2021)

rabler said:


> I don't know what "dead control" means?



I think Karl means a CNC knee mill with a broken computer.  A rather common problem with old machines.  The mechanics of the machine far outlives the old computers (or even the new computers).  I expect my machines will still be mechanically functional 100 years from now, but the computers will be long dead.


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## rabler (Oct 22, 2021)

JimDawson said:


> I think Karl means a CNC knee mill with a broken computer.  A rather common problem with old machines.  The mechanics of the machine far outlives the old computers (or even the new computers).  I expect my machines will still be mechanically functional 100 years from now, but the computers will be long dead.


That makes sense.  Karl, pardon me being a bit slow.


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## Karl_T (Oct 23, 2021)

Say Jim, what control would you suggest for the OP?  My Camsoft and your custom controls are a bit over the top for a first timer.  Mach used to be suggested, sounds like that one is not so much any more. linux CNC?? Centroid??  I really have not kept up here.

I do like those DMM servos you turned me on to. They come with a step driver for the low end controls. After ALL YOUR HELP, getting +/- 10 volt  analog servo mode going, they are wonderful. But I do not know a control to suggest that can use this. My .02 putting low end stepper control on a VMC is just wrong.

Rabler  - you should know stepper controls do NOT take feedback from the servos. They just issue commands and expect the machine did it right. I put this concept on rebuilds in the 90s. After ruining only the high dollar parts, I went out and found a servo control with position feedback. My opinion - stepper control is for low end hobby use only. maybe I am a snob. But its a well earned opinion.


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## rabler (Oct 23, 2021)

Karl_T said:


> Rabler  - you should know stepper controls do NOT take feedback from the servos. They just issue commands and expect the machine did it right. I put this concept on rebuilds in the 90s. After ruining only the high dollar parts, I went out and found a servo control with position feedback. My opinion - stepper control is for low end hobby use only. maybe I am a snob. But its a well earned opinion.


I'm aware that steppers can miss a step if overloaded, and that this can cause real problems.  I'm aware that servo motors are considered the solution, but I'm not sure which software solutions are able to take advantage of this, or if it is handled in the hardware servo driver.  Some learning to do.


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## rabler (Oct 23, 2021)

I spent an hour this morning skimming Charlieman22's thread.
I have an oscilloscope, DVM, and a Keysight 3 channel DC supply, so the basics for testing.  
At this rate I'm going to end up with a VMC before I have a shop to put it in


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## JimDawson (Oct 23, 2021)

Karl_T said:


> Say Jim, what control would you suggest for the OP? My Camsoft and your custom controls are a bit over the top for a first timer. Mach used to be suggested, sounds like that one is not so much any more. linux CNC?? Centroid?? I really have not kept up here.


@rabler suggested he would like to use LinuxCNC since he has experience with Linux.  Mesa or Galil products are compatible with LinuxCNC and both have +/- 10V analog control capability.  There may be others also.



Karl_T said:


> I do like those DMM servos you turned me on to. They come with a step driver for the low end controls. After ALL YOUR HELP, getting +/- 10 volt analog servo mode going, they are wonderful. But I do not know a control to suggest that can use this.



I have been happy with my DMM servos, they have been running my lathe for the last 3 years, running almost every day.  I did just replace my spindle motor with a 7.5kW Delta (Automation Direct SureServo2) servo motor to have full C axis capability.  Very happy with the Delta system also.


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## JimDawson (Oct 23, 2021)

rabler said:


> I'm aware that servo motors are considered the solution, but I'm not sure which software solutions are able to take advantage of this, or if it is handled in the hardware servo driver.



The servo loop can be closed at the drive or at the controller level.  All modern servo motors have a built in encoder that is connected to the drive.  The drives also have an encoder output that can be connected to the controller.

Normally if the loop is closed at the drive, the system is commanded by step & direction signals just like a stepper system.  The drive does its best to move the motors to the commanded position.  This works very well.

Closing the loop at the controller is done by connecting either the drive encoder output or an external encoder to the controller and commanding the drive with a +/- 10V analog signal.  My preferred method of doing this is to use a magnetic encoder attached to the load (table) and connect that to the controller.  This automatically compensates for any backlash (within reason) and any ball screw error.

Basically any software solution can use one or either of the above systems, just depends on your preferred software.

It may be possible the use the existing servo motors and drives on any VMC you choose to buy.  Just depends on the installed hardware, and what documentation is available for that hardware.


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## Karl_T (Oct 23, 2021)

JimDawson said:


> @rabler suggested he would like to use LinuxCNC since he has experience with Linux.  Mesa or Galil products are compatible with LinuxCNC and both have +/- 10V analog control capability.  There may be others also.
> 
> 
> 
> I have been happy with my DMM servos, they have been running my lathe for the last 3 years, running almost every day.  I did just replace my spindle motor with a 7.5kW Delta (Automation Direct SureServo2) servo motor to have full C axis capability.  Very happy with the Delta system also.




Rabler, The Galil card is a SUPER DUTY real time controller. If LinuxCNC works well with it, that would be a top end solution. Both Jim and i are sold on using the Galil products for machine control.


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## rabler (Oct 23, 2021)

Karl_T said:


> Rabler, The Galil card is a SUPER DUTY real time controller. If LinuxCNC works well with it, that would be a top end solution. Both Jim and i are sold on using the Galil products for machine control.


Yes, I saw that mentioned in Charlieman22's thread and caught that Jim said it was compatible with linuxcnc.  I also found threads on the linuxcnc site showing it was supported.

While a far cry from completely understanding it, at this point I'm comfortable enough with the linuxcnc->galil interface and C library support that I'm going to focus on VMC specs and prices to see what makes sense in terms of a physical machine.  



JimDawson said:


> It may be possible the use the existing servo motors and drives on any VMC you choose to buy. Just depends on the installed hardware, and what documentation is available for that hardware.



It would be nice to reuse the existing servo and drives as they're not cheap.  Anything I should look for or avoid in this department?  I'm browsing VMCs to get a feel for cost, weight, power requirements, size, and capabilities to see what makes sense to me personally.


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## rabler (Oct 23, 2021)

Since the spindles run on a VFD, is it reasonable to use an appropriately oversized VFD to run one directly off single phase 220V?  Looks like the rest of the electronics is mostly a matter of AC->DC conversion, that's easy enough to manage on single phase?   I would imagine the servo's need  a bit of amperage.

I have a 20HP RPC and am not opposed to upgrading that, but am not sure there is a need.


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## JimDawson (Oct 23, 2021)

rabler said:


> It would be nice to reuse the existing servo and drives as they're not cheap. Anything I should look for or avoid in this department? I'm browsing VMCs to get a feel for cost, weight, power requirements, size, and capabilities to see what makes sense to me personally.



The existing controls would not be a deciding factor for me. Overall mechanical condition is much more important.  

Post 1987 Fanuc red cap motors/drives are basically not compatible with anything but a Fanuc controller.  The Fanuc yellow cap (DC) motors/drives may be compatible with other controls.  Most other controls use more conventional servo motor control.  Availability of documentation for the existing motors/drives is also important.


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## JimDawson (Oct 23, 2021)

rabler said:


> Since the spindles run on a VFD, is it reasonable to use an appropriately oversized VFD to run one directly off single phase 220V?  Looks like the rest of the electronics is mostly a matter of AC->DC conversion, that's easy enough to manage on single phase?   I would imagine the servo's need  a bit of amperage.
> 
> I have a 20HP RPC and am not opposed to upgrading that, but am not sure there is a need.



The existing spindle MAY run off of a VFD if it is not a servo spindle (the line between a VFD and a servo drive is a little blurry today).  While it is possible to oversize a VFD and run it off of a single phase supply, since you already have a substantial RPC, I see no reason to do that.  If the installed spindle motor is a more or less standard 3 phase induction motor, then it would run fine on a VFD.  If the installed axis drives are brushed DC motors, then running those on single phase is no problem.  If they are AC servos, then most likely would need 3 phase.  New axis drives could most likely be run on single phase.

Just to put this in perspective let's take the case of my lathe.  7.5kW (10HP) servo spindle, four 1.8kW servo axis drives, one 2HP hydraulic pump, and other misc. hardware all happily running on a 15HP RPC.  Prior to upgrading my 7.5kW Fanuc spindle motor, I was running it off of a VFD.  Interesting enough, my power usage actually went down after replacing the original spindle motor with the servo system.


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## Karl_T (Oct 23, 2021)

Yep, just look at the color of the fanuc servos, red=bad, yellow=good. 

I agree with Jim, machine condition is FAR more important.


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## rabler (Oct 23, 2021)

Looked at a Tree 750 VMC tonight just a few miles down the road.  Probably bigger than I need, but it helps bring it together in my mind.


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## ArmyDoc (Jan 2, 2022)

Any updates on this?


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## rabler (Jan 18, 2022)

ArmyDoc said:


> Any updates on this?


Sorry, missed your comment until just now.  I'm working on building a new shop: https://www.hobby-machinist.com/thr...uildings-expansion-building-on-a-grade.91117/

Contractor is suppose to start "By the end of January" (Jan 3 was the original tentative start date).  Until I get the additional square footage, I don't have room for the tools I already have much less a decent sized VMC.   Just today I was working on building out the new meter panel to upgrade the power feed to 400A for the house, so I'll basically have a 200A service to the house and a 200A service to the new shop.  To run a VMC I may have to also upgrade my RPC, currently using a 20HP on a WNY panel.  Looking at adding another 10HP or 20HP idler and making that one a pony start to avoid the horrendous inrush on starting a large RPC necessary to feed a VMC and still allow other things to be going on in the shop.


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## rabler (Oct 6, 2022)

Almost a year later.  Shop is almost done.  Still need to put in the NG heater and the flu on the wood stove.  Heat pump mini-splits will suffice for mild fall weather.

Went to visit another hobbyist that is looking to get into building some things as a sideline revenue stream.  He went from CNC'ing a PM-30V to buying a new Okuma M560-V, a monster 18,000 lb VMC.  Impressive what he can turn out, but certainly not what I'd consider a hobbyist budget given the 6 figure cost of the machine, before shipping and rigging and ....  

Still like the plan of retrofitting an older VMC with newer electronics/controller.  I do think something with an ATC is in the cards even if it isn't a day one feature.


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## Karl_T (Oct 6, 2022)

If you are going to refit a pro size machine with an ATC, I'd strongly suggest Camsoft.  I have done half dozen refits with this software over the years. Very similar to the custom software way that Jim Dawson goes. I'd suggest you use him for all the servo and drive selection

This is quite a huge project the first time - steep learning curve here.

karl


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## rabler (Oct 6, 2022)

Karl_T said:


> If you are going to refit a pro size machine with an ATC, I'd strongly suggest Camsoft.  I have done half dozen refits with this software over the years. Very similar to the custom software way that Jim Dawson goes. I'd suggest you use him for all the servo and drive selection
> 
> This is quite a huge project the first time - steep learning curve here.
> 
> karl


I’ll add camsoft to my list of things to dig into.


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## rabler (Oct 14, 2022)

Made a deal on that Tree 750 VMC.  Next need to haul it the 3-4 miles from its current residence to my shop.


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## Boswell (Oct 14, 2022)

rabler said:


> Made a deal on that Tree 750 VMC.


OMG, that is a BEAST


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## rabler (Oct 14, 2022)

Boswell said:


> OMG, that is a BEAST


It will fit right in with my huge surface plate, 25" swing lathe, and WWII K&T 3k mill.   They all weigh about 4-5 tons each.


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## rabler (Oct 16, 2022)

The NT 4.0 based Siemens acramatic 2100 controller on this machine has lost it's nvram battery so the BIOS is shot.   Current owner tried  troubleshooting it but I think he made more of a mess of it.  Windows NT gives me heartburn  

 I've taken a dive into looking at LinuxCNC, and am pretty well set on that route.  May not be the right route in general but I have a predilection for open source software, and have years of experience messing with embedded Linux, realtime extensions (for software radio, but same concept) , C programming, and even some kernel hacking.   VHDL programming for the MESA FPGAs would be a bit of a stretch but probably not necessary.  So rebuilding the controller is rather tantalizing, as I'll then know the guts of the machine inside out.  Unfortunately MESA cards are unobtainium right now given the chip shortage.   But it'll probably be a month before I even get the machine moved.


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## Karl_T (Oct 16, 2022)

Say, i did a search for Mesa cards just for grins. I see their I/O card does 8 out 16 in and is out of stack. You'd need more than one to do a tool changer.

I have used adlink's PCIe 7296 cards on several machines. It does a total of 96 I/O configurable in blocks of 24 to either input or output. This card has a linux driver, maybe work for you???









						PCIe-7248/7296 | Digital I/O | ADLINK
					

Digital I/O,96/48-CH Opto-22 Compatible PCI Express Digital I/O Cards




					www.adlinktech.com


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## rabler (Oct 18, 2022)

Karl_T said:


> Say, i did a search for Mesa cards just for grins. I see their I/O card does 8 out 16 in and is out of stack. You'd need more than one to do a tool changer.
> 
> I have used adlink's PCIe 7296 cards on several machines. It does a total of 96 I/O configurable in blocks of 24 to either input or output. This card has a linux driver, maybe work for you???
> 
> ...


Hey Karl,

The Mesa configuration that I'm looking at is the 6i25 PCIe card with the 7176 breakout card.  That configuration costs about $240 when available.  Of course when not available price is meaningless.  But that combo has seventeen 5 volt I/O pins on the 6i25, plus: The 7I76 is a step/dir oriented breakout with 5 axis of buffered step/dir outputs, one spindle encoder input, one isolated 0-10V analog spindle speed plus isolated direction and enable outputs, one RS-422 expansion port, 32 isolated 5-32V inputs and 16 isolated 5-32V 300 mA outputs.  Looks like the Yaskawa servos lean heavily on 10 volt differential signaling for digital, and 10volt analog for the spindle, so this looks like a good match if the servos are configured for step/dir operation.

LinuxCNC's general philosophy is to run a lot of things in software and uses a real-time kernel loop to handle most things.  In the original parallel port implementation this was heavily dependent on system latency and corresponding jitter, so a lot of tuning/tweaking the PC config to get low latency was critical.  The MESA cards use an FPGA on the card to handle _some_ of the timing, at least at the pulse timing level, which seems to be a significant improvement.  A bit of browsing on the LinuxCNC forum doesn't show any special support for the ADLINK card so I think it would end up as a fancy parallel port implementation, with the end result being that the VMC would possibly run slower and/or have more trouble doing smooth operations such as circlular operations.  If all that's correct I'm willing to wait a few months to see if the Mesa cards are available.

I believe the Galil controllers are a full motion controller, so they take the front end out of the timing loop to a much larger extent. 

At least that's my naive understanding of all of this, perhaps I'm missing something?


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## Karl_T (Oct 18, 2022)

Sounds like you have good plan, looks pretty cost effective assuming it all works well.

The galil, adlink, Camsoft route would be quite a bit more expensive. Yes, the Galil card does all the real time motion control. Especially the current 18X6 cards are incredibly fast - way beyond the needs of most mere mortals. I have always used the older 18X0 cards - cheap on ebay and still much  beyond my needs.

if you have the time keep us posted on your progress here. I'd like to learn more about Linux CNC control.


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## rabler (Oct 18, 2022)

Karl_T said:


> Sounds like you have good plan, looks pretty cost effective assuming it all works well.
> 
> The galil, adlink, Camsoft route would be quite a bit more expensive. Yes, the Galil card does all the real time motion control. Especially the current 18X6 cards are incredibly fast - way beyond the needs of most mere mortals. I have always used the older 18X0 cards - cheap on ebay and still much  beyond my needs.
> 
> if you have the time keep us posted on your progress here. I'd like to learn more about Linux CNC control.


Gladly keep this thread updated.  So far I’ve pulled an old quad core PC off my misc boat anchors stack, stripped out the fancy graphics card, and got linuxcnc installed on a 500Gb SSD. Initially got 25usec in the jitter tests.  Some BIOS tweaks: hyperthreading,virtualization off, sound card and fan control off, jitter down to 21usec.  Adding another pair of memory sticks should help so I ordered two.  Shouldn’t be critical if I can get a Mesa card.  The Mesa card is essentially a big FPGA sitting between the linux PC and the I/O lines, so it can send and decode quadrature signals, turn output pairs into differential or independent outputs, etc.

I also ordered a bigger toe jack to help move the VMC. Everything else is playing until I get it moved.


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## WobblyHand (Oct 19, 2022)

Out of curiosity, what does the jitter test do?  Is this the time jitter writing to some port?  21us sounds like a lot, is this with a RT kernel?

It's no replacement for an FPGA, but a 600 MHz Teensy 4.x (standard clock rate) has no issue doing software quadrature encoder (interrupt driven) reading at 400 KHz, (2.5us) the HW quadrature encoder is much faster.  This 2.5us rate is with the rest of my ELS code running.  Very simple development, IMHO.  Might not be suitable for your application, though.


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## rabler (Oct 19, 2022)

WobblyHand said:


> Out of curiosity, what does the jitter test do?  Is this the time jitter writing to some port?  21us sounds like a lot, is this with a RT kernel?
> 
> It's no replacement for an FPGA, but a 600 MHz Teensy 4.x (standard clock rate) has no issue doing software quadrature encoder (interrupt driven) reading at 400 KHz, (2.5us) the HW quadrature encoder is much faster.  This 2.5us rate is with the rest of my ELS code running.  Very simple development, IMHO.  Might not be suitable for your application, though.


Yes, I've thought of that.  GRBL is an arduino project that implements G-code, it would be the easiest approach to using an embedded microcontroller.  Putting that on a Nano would be an easy, open source software approach.  Still need some sort of computer in front of the microcontroller to run a GUI and feed it G-code, but no more worries about real-time.    It is really just controlling 3 leadscrews verses the 1 your ELS is doing.

Since the existing servos are all 10v differential signaling, any solution is going to require some I/O hardware.

Linuxcnc requires a real-time kernel, and for simplicity the standard Linuxcnc download is a full debian install with the RT kernel.  The jitter test sets up a periodic interrupt and then measures the *worst case* variation from the nominal period.  That worst case is a function of other interrupts that may be occuring on the system.  The real time kernel can only really control linux timing, some timing associated with multiprocessors, fans/cooling, etc are handled by the BIOS and outside of the rt kernels control.  21us is considered OK, not great (10-15us) but not bad (>30us).   Getting good worst-case jitter has been the challenge in using Raspberry PI based controllers.  Most full-computer CPUs are optimized for performance around human timeframes, where 1ms response is more than sufficient. There are some hacks to completely remove cpu cores from the standard multiprocess scheduling (isolcpus) that may help more.

LinuxCNC appears to me much fuller featured.  It implements a broader range of G-codes, and has significant graphics visualization tools.  The FPGA based hardware card is already set up with voltage drivers for high voltage controls and differential signaling, in addition to the timing.  Availability of hardware is a real challenge given the current chip-shortage issues, whatever approach you take.

There are versions of the FPGA card that connect via ethernet.  An intriguing and popular linuxcnc configuration is to use an RPI4 with one of those cards.  The FPGA card is directly connected w/o a switch for best performance.


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## WobblyHand (Oct 19, 2022)

GRBL, I believe, has been ported to the Teensy, which to me, makes it a much more viable system.  The Teensy 4.x is a pretty darn good microcontroller.  32 bit ARM M7, which normally runs at 600 MHz vs whatever a Nano is.  The Teensy can flip bits in a couple nanoseconds.  Beats the pants off an Uno/Nano!

Although PJRC went through a tight stretch for a bit, Teensy 4.1 is available for it's normal price.  It also has built in ethernet (10/100 Mbit) should you desire to remotely control it that way.  $31.50 with ethernet, although you need to buy a magjack kit for $3.90.  My experience this platform has been quite favorable.  Could use an RPI4 (if you have one!) for the GUI front end and let the Teensy 4.1 do the real time control.

https://www.pjrc.com/store/teensy41.html for more info.  I have no financial ties or interest in PJRC whatsoever, just a happy user of Teensy4.1.  For a comparison of the performance of microcontrollers, check out the CoreMark scores on that page.  Won't directly translate into performance, but it give you an idea of the _orders of magnitude difference_ between the controllers.


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## rabler (Oct 19, 2022)

Yeah, the AVR processors used in the basic Ardiuno kits are slow and pretty limited.  There really are a ton of solutions out there.  Trying to figure out which one is "best" is not a trivial exercise.  Arduino is optimized for *cheap*, after all "Arduino" is really a development environment not a microcontroller.  Lots of options, PICO, AVR, esp32, teensy, beaglebone (Although I have had real problems with TI stuff), etc.  Of course really high performance would come with using one of the FPGAs that include an ARM core on-chip. 

I do actually have an unused RPI4, which I bought as a future home automation server for the workshop, but haven't gotten around to.  I have more projects than hours in a day, no different than most people here!


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## rabler (Oct 23, 2022)

Here's a summary of this weekend in pictures.  About 9 hours of pretty intense work with skates, cribbing, toe jacks, pry bars, etc.  Note the weekend ends with the VMC still sitting on the rollback ramp in front of the door of my shop.  About 5pm today I started getting tired to the point where I was thinking "I just want to be done with this".  That is not a safe mindset for moving multi-ton machinery.  The rollback belongs to the seller.  We chained it to the tractor to keep it from rolling downhill on the rather steep shop entrance.   He was fine leaving it parked there overnight, or for a couple weeks, whatever works out.  Nice to work with people who are easy to work with.

The frame underneath the mill is about 3' wide left/right/ and about 6' front to back.  I made the call to put it on the rollback facing rearward to give it the widest stance while being winched up.   It was only about 3 miles to move it, all on back roads.  Trip was made at about 15 MPH.  I was originally planning on renting a tilt deck equipment trailer to haul it but the fellow selling this offered to put it on the rollback given the short trip.  I gave him an extra $100 today for his time and effort, a pittance in today's economy, but that was the cash I had on hand.


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## extropic (Oct 23, 2022)

That's an amazing trifecta.

A decent VMC (I trust your judgement) within your budget, only a few miles away and the seller lets you borrow his rollback.

That has to qualify for a


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## rabler (Oct 23, 2022)

While the rollback has a leg several feet behind the rear axle that lowers to the ground, that requires extending and tilting the bed somewhat.  There was a point in this process where the front wheels of the rollback started dancing sideways, close to lifting the front end.  Probably could not have come up far as the tractor chain wouldn’t allow that, but illustrates that you have to keep watching everything and not be under or near anything that could shift.  We spotted that happening and re-strategized by use of some cribbing.


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## matthewsx (Oct 24, 2022)

rabler said:


> Here's a summary of this weekend in pictures.  About 9 hours of pretty intense work with skates, cribbing, toe jacks, pry bars, etc.  Note the weekend ends with the VMC still sitting on the rollback ramp in front of the door of my shop.  About 5pm today I started getting tired to the point where I was thinking "I just want to be done with this".  That is not a safe mindset for moving multi-ton machinery.  The rollback belongs to the seller.  We chained it to the tractor to keep it from rolling downhill on the rather steep shop entrance.   He was fine leaving it parked there overnight, or for a couple weeks, whatever works out.  Nice to work with people who are easy to work with.
> 
> The frame underneath the mill is about 3' wide left/right/ and about 6' front to back.  I made the call to put it on the rollback facing rearward to give it the widest stance while being winched up.   It was only about 3 miles to move it, all on back roads.  Trip was made at about 15 MPH.  I was originally planning on renting a tilt deck equipment trailer to haul it but the fellow selling this offered to put it on the rollback given the short trip.  I gave him an extra $100 today for his time and effort, a pittance in today's economy, but that was the cash I had on hand.
> View attachment 424442
> ...





matthewsx said:


> We've seen your lathe....
> 
> I can't imagine anything less than a full size VMC would be suitable in the new shop you're building. Haas, Fadal, Mazak, etc.
> 
> ...


Love it when people listen to my totally reasonable advice....

Congratulations, looking forward to seeing it commissioned and put into use 

John


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## matthewsx (Oct 24, 2022)

rabler said:


> Hey Karl,
> 
> The Mesa configuration that I'm looking at is the 6i25 PCIe card with the 7176 breakout card.  That configuration costs about $240 when available.  Of course when not available price is meaningless.  But that combo has seventeen 5 volt I/O pins on the 6i25, plus: The 7I76 is a step/dir oriented breakout with 5 axis of buffered step/dir outputs, one spindle encoder input, one isolated 0-10V analog spindle speed plus isolated direction and enable outputs, one RS-422 expansion port, 32 isolated 5-32V inputs and 16 isolated 5-32V 300 mA outputs.  Looks like the Yaskawa servos lean heavily on 10 volt differential signaling for digital, and 10volt analog for the spindle, so this looks like a good match if the servos are configured for step/dir operation.
> 
> ...


I have a Mesa 7i96 that's I bought a few years back for my CNC mill/drill project thats just been languising in a project box. Think it's about time to resurrect my interest in CNC with my new job and all.

John


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## rabler (Oct 26, 2022)

Lost a couple days to a nasty cold (maybe covid?).  Gravity wasn’t enough to slide/roll it off.  We pulled the skates out for transporting, and I wasn’t willing to get under the downhill side to jack and put in skates, so two skates under the high side.  I drilled some holes in the concrete and set three anchors bolts into a shop-made anchor plate.  Makes it fairly easy to pull from a safe distance, with the rollback winch still attached to prevent runaway.  Only moved it another 4-5 feet today before the remains of whatever sickness won for the day.


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## extropic (Oct 27, 2022)

Very nice. and safe progress on the unload.

I hope you feel 100% soon.


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## BGHansen (Oct 27, 2022)

rabler said:


> Lost a couple days to a nasty cold (maybe covid?).  Gravity wasn’t enough to slide/roll it off.  We pulled the skates out for transporting, and I wasn’t willing to get under the downhill side to jack and put in skates, so two skates under the high side.  I drilled some holes in the concrete and set three anchors bolts into a shop-made anchor plate.  Makes it fairly easy to pull from a safe distance, with the rollback winch still attached to prevent runaway.  Only moved it another 4-5 feet today before the remains of whatever sickness won for the day.


I'm sure your wife more than supports your cautious and safe approach!  I've done some pretty stupid things that could have ended very badly.  Unfortunately, my wife was the witness to one of them; she doesn't let me forget it!  

Bruce


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## matthewsx (Oct 27, 2022)

You


rabler said:


> Lost a couple days to a nasty cold (maybe covid?).  Gravity wasn’t enough to slide/roll it off.  We pulled the skates out for transporting, and I wasn’t willing to get under the downhill side to jack and put in skates, so two skates under the high side.  I drilled some holes in the concrete and set three anchors bolts into a shop-made anchor plate.  Makes it fairly easy to pull from a safe distance, with the rollback winch still attached to prevent runaway.  Only moved it another 4-5 feet today before the remains of whatever sickness won for the day.
> View attachment 424795


You’ll get it done. Stay safe, stay healthy. 

John


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## rabler (Oct 27, 2022)

> @matthewsx said: You’ll get it done. Stay safe, stay healthy.



Still a bit off at the tail end of whatever was ailing me, but well on the mend.  Mill is off the rollback, inside the door of the shop, with the door closed.  It still needs to make the trip across the shop to it's resting place near the rear of the shop with the other large machines, but I can do that without the worry of rain and humidity in the shop.  Now that it is sitting on solid concrete rather than tilted precariously on a rollback deck, I can put the third skate under it to make it relatively easy to roll.  And the previous owner can have his rollback truck back.

Any good post (even a few sithy posts)  needs a picture, so here's a bit of a closer view of the floor plate, come-along, and chain.   The orange fiberglass stick is convienent for sliding things under the mill while keeping body parts at a somewhat safer distance.  The rod in the bottom right almost out of frame is handy for turning the skates, their angle needs to be tweaked every few feet.


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## rabler (Oct 27, 2022)

BGHansen said:


> I'm sure your wife more than supports your cautious and safe approach!  I've done some pretty stupid things that could have ended very badly.  Unfortunately, my wife was the witness to one of them; she doesn't let me forget it!
> 
> Bruce


My wife is often my co-conspirator in stupid things, although between the two of us we usually manage to avoid the least safe of those.   I'd be in trouble without her!


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## rabler (Oct 31, 2022)

The VMC has finally reached its intended destination, and is off the skates and back on the leveling feet.  The chip tray on the right side is a little tight with the wall but it does come out.  That's not going to be an issue for a while.  I left plenty of room around back to work on the electronics.  For now it is on the project list. First thing is to move my big granite CMM table/surface plate back into position.  Then  I'll need to run conduit w/ 3Φ to it to even test the old controller.  I probably could boot that with just 220/110 if I wanted to jury rig something.  I'll need to enhance my RPC to actually fully power this thing.  I have a 20HP idler right now, probably will add a second idler, either 10 or 15HP, and stage them.

I did get a full image backup of the hard drive of the Acramatic 2100 controller, and I can loopback mount that on my linux box to check out the files.  That was an 80GB hard drive apparently installed in 4/2004.  The original drive was a 1.6GB hard drive, which had bad sectors, but I also backed up/recovered all but 8kB of that drive, those sectors wouldn't read.  But at least I have copies of those.  I'm not totally set on converting it to LinuxCNC if I can get the original controller working.  It even has an ethernet card, almost certainly 10Mb since it has a BNC jack on it for thinnet in addition to an RJ-45 port.  Of course a truly brave sole could try to install an old 32 bit Linux on the original controller, but linuxcnc drivers for the existing cards would be a challenge.  I have not been able to find documentation on the internals of a Siemens Acramatic Controller, although I have not tried exhaustively.

Anyhow, I think it looks appropriate with the other 5000lb+ machines, modern technology offset by the little hand crank drill press on the divider wall.  For now I'm back to scraping in my straight edge and working on the 12" rotary table automation.


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## matthewsx (Oct 31, 2022)

rabler said:


> The VMC has finally reached its intended destination, and is off the skates and back on the leveling feet.  The chip tray on the right side is a little tight with the wall but it does come out.  That's not going to be an issue for a while.  I left plenty of room around back to work on the electronics.  For now it is on the project list. First thing is to move my big granite CMM table/surface plate back into position.  Then  I'll need to run conduit w/ 3Φ to it to even test the old controller.  I probably could boot that with just 220/110 if I wanted to jury rig something.  I'll need to enhance my RPC to actually fully power this thing.  I have a 20HP idler right now, probably will add a second idler, either 10 or 15HP, and stage them.
> 
> I did get a full image backup of the hard drive of the Acramatic 2100 controller, and I can loopback mount that on my linux box to check out the files.  That was an 80GB hard drive apparently installed in 4/2004.  The original drive was a 1.6GB hard drive, which had bad sectors, but I also backed up/recovered all but 8kB of that drive, those sectors wouldn't read.  But at least I have copies of those.  I'm not totally set on converting it to LinuxCNC if I can get the original controller working.  It even has an ethernet card, almost certainly 10Mb since it has a BNC jack on it for thinnet in addition to an RJ-45 port.  Of course a truly brave sole could try to install an old 32 bit Linux on the original controller, but linuxcnc drivers for the existing cards would be a challenge.  I have not been able to find documentation on the internals of a Siemens Acramatic Controller, although I have not tried exhaustively.
> 
> ...


Looking good


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## rabler (Oct 31, 2022)

matthewsx said:


> Looking good


Thanks.  I would have held off a bit longer but it seems to be a pretty good project candidate and it was close, relatively easy to move.  The previous owner had it in a small commercial space that he's looking to sell after buying a home in the country that has suitable space, so he was ready to sell it.  He had found a deal on a newer used Haas that is in running condition.  Nice guy, professional machinist but likes tinkering on his own too.  Just doesn't have enough electronics background to really dig into troubleshooting older machines.


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