# Looking for advice on a small (ish) mill



## Crutches56 (Feb 20, 2018)

Greetings everyone! I'm looking to buy a (relatively) small mill and lathe. I own and run a small atv/motorcycle repair shop. I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts. The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table). 

I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....) 

Thoughts?


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## tq60 (Feb 20, 2018)

Avoid a round column mill.

The work envelope is not so great and you are limited by spindle travel.



Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## 7milesup (Feb 20, 2018)

Take a look at Precision Matthews equipment.  http://www.precisionmatthews.com/  Better warranty than Grizzly and far better customer service, although Grizzly still isn't bad.

I agree with tq60, avoid a round column mill.


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## mikey (Feb 21, 2018)

Crutches56 said:


> I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.
> 
> ... I can probably only spend up to $1500 on a mill setup right now.
> 
> ...



In an ideal world, yes, avoid a round column mill. However, you have a budget of $1500 and your stated goals are not complex. 

Crutches, are you sure about the Jet? I know they make a JMD 15 and a JMD 18 and I suspect the mill in question is an 18. If so, it will weigh close to 400# without the stand and has a 3" diameter quill with 5" of travel so it is, in fact, a really good heavy duty drill press. It will flycut quite well and handle most any small motorcycle part. I own an RF-31 which is essentially the same machine and after upgrading the bearings, it has under 0.0001" of spindle run out. I know what this machine can do and other than the issues common with the round column mills, it is quite a capable machine. It may suffice and earn you enough money to upgrade to a knee mill at a later date and I would consider it. 

Depending on its condition and tooling, $950 may be high. I would take a dial test indicator and a magnetic stand and check the spindle run out. Run the machine on high speed for about 15 minutes and then check to see what kind of concentricity you can get out of the spindle. If it is the thousandths then that right there is your ammo to get the price down. If those spindle and drive sleeve bearings are stock then I would bet money the runout will be anywhere from 0.001 - 0.003" or more. Tell him that replacement bearings will run about $300.00 and the labor to install them will run close to $150.00. See if he'll take $500-600 instead. You never know. If he plays hardball then just walk away. If he bites then the cost for the drive sleeve bearings will be under $30.00 for the pair. The spindle bearing OEM replacements should be under $150, possibly much less. Angular contact bearings can be pricey but I did mine for about $100.00. Not too bad.

If you are not sure how to check concentricity then say so and we'll tell you how. I believe that in your situation the machine has to earn its keep and for your simple needs, that Jet mill drill would work just fine in my opinion.


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## Mitch Alsup (Feb 21, 2018)

Crutches56 said:


> I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.



Don't try to fly cut cylinder heads with a mill weighing less than 1000 pounds (and 2000 pounds is better).



> The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table).



I have the big brother of the 6*26 (as a 8*30 G0730) and love using it (although it's not a Bridgeport....)



> I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....)



Stay away from round column mill/drills.


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## Billh50 (Feb 21, 2018)

I don't know why people put down round column mills so much. Sometimes it is all one can afford or fit in the space they have. And if care is taken they will do the job for what the OP is looking to do. I know because that is the type of work I have done on a round column mill with no problems. The only time he will need a larger mill, that I can foresee, is for 4cylinder heads as they will be too long for the travel of the round column mills. As far as fly cutting he should only be taking minimal cuts just to clean the heads.


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## SSage (Feb 21, 2018)

Save up and buy a decent mill. I've seen huge Bridgeports go for a $1000. Just a pain to move and feed them 3ph.

The Precision Matthews Pm727m is priced good for a small gear head unit. I think it's around $1500 new, can't remember. I've been happy with mine, I got the DRO version with the stand. It's better than the Grizzly version imo. 

DROpros sells small mills too. With a low budget your better finding one used on Craigslist if you're familiar with the machines and can identify the boat anchors.


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## chips&more (Feb 21, 2018)

How long are the heads you are going to fly cut??? To properly make a fly cut pass you should start and stop with the cutter past the edges of the head. Sooooo, if you do the math. If you total the length of the head and diameter of the fly cutter. That is approximately the table travel you need. And don’t assume a 48” table travels 48”. It does not! It’s much less!!! Doing a 1 cylinder head may not be a problem on a mid-size mill? But I would carefully check out table travel first...Dave


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## stioc (Feb 21, 2018)

Amazing amounts of work has been done on the round-column mills since the 80s! there's a reason they're still sold and purchased today.  Most people that down them usually have no direct experience and simply repeat others giving the same (ill?) advice. But yes, by all means, if you have the funds and you don't care to learn how to keep the z-axis alignment when dealing with short and long tools (that's the biggest and perhaps the only complaint on these) which takes all of 30 secs if you know the technique then buy a square column mill. Otherwise, if you're getting a bunch of tooling etc they can be a great bargain...


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## stioc (Feb 22, 2018)

So I got curious to see what the round-column mills are going for in my area and while they're all over the map ($600-$1500+ depending on what they come with) I particularly found this ad very interesting so I took a screenshot of it to post here. Also on youtube look for user cuppajoe, google Rick Sparber - among others who have had these for many years and have done good work on them. I'm in the process of converting mine to CNC...hopefully soon, if I can just stay focused on one hobby at a time.


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## Crutches56 (Mar 15, 2018)

Wow thanks guys. I didn't get emails that I had any responses. This was really nice to come back to. I have a friend who taught me the basics of machining, who I found out has an old Bridgeport. He converted it to a full cnc system, but it's been sitting on a trailer for 4 years. He said every 4 months, he'd go WD40 it, and replace the tarps around it. He Wants to open up his own shop, but can't do it in the next several years, so he's been saving it. But he offered to let it live in my shop, so it has a purpose. I'd get a rotary phase converter to give it 3ph. But the table is pretty rusty. He said he doesnt blame me if I don't want to mess with it at all. But dang... I'd only be paying for Transportation costs, de-rusting and the converter. He mentioned we should convert it back to manual, but doesn't have the hardware. 

I need to be able to bore these atv cylinders! I've had 3 come into the shop in the last week that I've shipped off to get bored. And the shop called and let me know they had an accident, and ruined a cylinder. Ah! So they're paying to sleeve it, then re-bore it. What machines do you guys have that you're looking to sell?


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## ACHiPo (Mar 15, 2018)

Congrats!  Sounds like a plan!  Might want to go the VFD route rather than rotary converter as it gives you easy speed control.

Pics or it didn’t happen!


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## Crutches56 (Mar 15, 2018)

chips&more said:


> How long are the heads you are going to fly cut???
> 
> Most of the heads we would do are single cylinder, but I do quite a few RZRs as well. Those heads are maybe 10" across.
> 
> And ACHiPo, we had talked about going VFD, but he said you can only get something like 70-80 % of the capacity of the motor with those, as opposed to the rotary, you can get more. Thoughts? And here are pictures. What do you guys think? Worth it? How hard would it be to convert it back to manual?


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## JimDawson (Mar 15, 2018)

That looks like a project.    Never seen a BP like that before.  Has a different table and knee than I have ever seen.  Looks like an Ericson BT30 QC spindle.


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## ACHiPo (Mar 15, 2018)

Crutches56 said:


> Thoughts? And here are pictures. What do you guys think? Worth it? How hard would it be to convert it back to manual?


Well Crutches, I'd say you've got a bit more than a small mill there!  That thing is a beast!  If it runs and the axes move, it seems like it would be worth some TLC especially if you get to hang onto it for a while.  Nice score.

It's definitely massive enough to do heads (and V-8 blocks!).

Regarding the VFD that motor may be big enough to be problematic for a VFD, although if it isn't, I wouldn't be terribly concerned about losing 20% power.


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## P T Schram (Mar 15, 2018)

Looks like a Bridgeport Series II maybe

One of the few that are really worth what everybody goes nuts over

That is a much heavier machine than your typical vertical universal machine and will serve you well for your intended purpose. The "standard" Bridgeport mill is much too light IMO and tends to chatter, but not their bigger machines. There was a series of early NC mills that were about as rigid as one could imagine but being early NC, many were scrapped when the CNC became standard-I used to know where there were two, and I was offered one if I helped the owner convert the other to more modern electronics 

You've done well young Jedi, and I hope,for your sake it lives in your shop a good long time


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## JimDawson (Mar 15, 2018)

I don't think that mill was ever manual, and if it was converted, then someone went through a heck of a lot of work machining castings to install the round rails. That knee and saddle are nothing like anything I have ever seen on a BP, but looks like a factory instalation.   It could be operated manually simply by hanging some handwheels on the axes.



ACHiPo said:


> Regarding the VFD that motor may be big enough to be problematic for a VFD, although if it isn't, I wouldn't be terribly concerned about losing 20% power.



That looks like a standard 2HP BP spindle motor, but could be a 3HP.  In either case would be no problem for a VFD.  And no, you won't lose 20% power with a VFD, you will get full power with a better torque curve.  If you were using a static phase converter, then you would lose about 33% because the motor is only running on single phase


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## P T Schram (Mar 15, 2018)

JimDawson said:


> I don't think that mill was ever manual, and if it was converted, then someone went through a heck of a lot of work machining castings to install the round rails. That knee and saddle are nothing like anything I have ever seen on a BP, but looks like a factory instalation.   It could be operated manually simply by hanging some handwheels on the axes.


That is Bridgeport's first entre into the world of NC and I think you'll have a LOT more work trying to put handwheels on it than you'd expect and you'd be disappointed in the performance.

With new electronics it can be a Helluva machine


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## Crutches56 (Jun 10, 2019)

Alright guys, it's been a journey... I bought a rottler boring bar on ebay shortly after making this post last year. I've been boring atv cylinders with it, and it's worked, but I've needed a mill to do other things. So I bought a 50's round ram Bridgeport in ebay that had a J-head installed. Long story short: freight companies were a nightmare to deal with, and kept having logistic errors, which caused the seller to get mad, and repost it. So I lost it. Ill get my money back, but don't have the mill. I was telling this friend of mine about it, and he said. "well that Bridgeport is still sitting on the trailer. I'd like to not have to worry about it. It's yours. Take it for free. Clean it up and use it and it's yours."

So he said it's a Bridgeport series 1, that the company he worked for upgraded. It has full linear ball screws on the Y that are tight, can do 0.0005" well. He said we should ditch the cnc, convert it back to manual. They put a 54" table on it. 

So I'm going to go up (about 2 hours away) and we will see about getting it onto my trailer. So here's my questions:

Advice... What are the first things you want to say about it? (or about how much you hate me ) 

Where do I start? Soak it in wd40? Take the table off? 

Just sit and drool over it? 

Where can I source hand cranks for it? Besides ebay? 

Thanks! I'm excited for the journey.


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## matthewsx (Jun 11, 2019)

Well, the price is right.  If you have the space jump on it.

Don't know if I would bother converting it to manual, you'll get better cuts with the servo drives and providing they work it should cost a lot less than finding/fabing all the stuff to change it. The control and drivers have come way down in cost since that unit was built and LinuxCNC is free.

Disclaimer, I'm just getting started with CNC but I am a computer guy. I also used to own a small engine shop and did racing kart engines so I know what kind of work you're doing. I suspect a lot of folks think CNC is going to be too complicated, or the time to do a set-up will be a lot more than just putting their work in the vise and cranking away with it. Your buddy might be one of those, or he might really know why this particular machine would be better manual. However, I'm gonna bet it will take a lot less time, effort, and $$$ to update the electronics than to try and convert it to manual. Most people go the other way for a reason.

There are lots of folks on here and CNCZone that will be helpful and with a machine like that you can even ask questions on Practical Machinist. Off the top of my head you'll need a control board (I bought a 5 axis for $20), servo drivers, and an older PC besides cleaning it up of course. I would figure out what the servos are and get one driver to test them with first. Once you get it running you can use a pennant to control it without having to actually write a program for what you need to do.

BTW, there are much better ways to remove rust than WD40 but that table doesn't look too bad. Some scotch brite and mineral spirits might be all you need. 

Congrats on your score, keep in touch and if you're looking for a small engine dyno let me know.

Cheers,

John


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## ThinWoodsman (Jun 11, 2019)

Crutches56 said:


> Where can I source hand cranks for it? Besides ebay?


Eisen has them:
handle
  handwheel

Also, for the rust, paper towels soaked in evaporust and held in place with magnets make a great first pass. When the paper towel dries out, go in with the scotchbrite and mineral spirits.


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## richl (Jun 11, 2019)

Mcmaster is a good source for many things also. Might be something to bookmark. Nice "smallish" mill lol wish mine was that small


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## P T Schram (Jun 11, 2019)

Everything I said at first still stands.

Buy it, convert to modern CNC controls, etc and make chips.

I'm jealous over your Rottller, I recently got a Kwik-Way but haven't had a chance to get it fired up yet.


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## hman (Jun 11, 2019)

Regarding conversion to manual ... just remember that, unlike Acme lead screws, ball screws can be back-driven, often with relatively low force.  So be sure to lock down the unused axes when milling.  Otherwise, your table might start wandering all over the place unexpectedly.

Other than that minor caution - Congratulations!


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## Crutches56 (Jun 11, 2019)

P T Schram said:


> I'm jealous over your Rottller, I recently got a Kwik-Way but haven't had a chance to get it fired up yet.



That rottler was the first piece of machinery I bought (besides a forklift haha). It is awesome to use, and produces an amazing cylinder. But selling it will fund tooling/upgrades for this new BP. I had someone offer $1k for it on ebay. I counter offered at $1100, but they didn't accept it. I started to take it out of commission today so I can crate it up to ship it.


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## Crutches56 (Jun 13, 2019)

So I'm hoping to go up this weekend and get this thing somehow. When I'm actually near it, I'll take pics of all the motors and stuff and post. I signed for cnczone, but holy!! There's a lot of places to post. Didn't know where to start. General cnc? 

I'll post pics of what this thing is and maybe someone can point a finger in the general direction, then I'll research like crazy and probably start spending at that point too. Haha.


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## matthewsx (Jun 13, 2019)

Crutches56 said:


> So I'm hoping to go up this weekend and get this thing somehow. When I'm actually near it, I'll take pics of all the motors and stuff and post. I signed for cnczone, but holy!! There's a lot of places to post. Didn't know where to start. General cnc?
> 
> I'll post pics of what this thing is and maybe someone can point a finger in the general direction, then I'll research like crazy and probably start spending at that point too. Haha.



Take your time figuring out how to move it, if your buddy already has it on a trailer it might be worth putting new tires and bearings on his rather than trying to transfer it without the proper forklift or crane to pick it up. Chain & strap it down good and take the journey slow with lots of stops to make sure everything is tight. Also make sure the boards/skid underneath are in good shape, you don't want that giving out on the highway. Be EXTRA CAREFUL, that thing weighs more than either of you think

As for CNCZone you can post in the general area and the moderators will move your post if needed. Certainly the first post from someone getting a new machine is always welcome. Posts with pictures of moving stuff is even better. 

Cheers,

John


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## Crutches56 (Jun 13, 2019)

matthewsx said:


> Take your time figuring out how to move it, if your buddy already has it on a trailer it might be worth putting new tires and bearings on his rather than trying to transfer it without the proper forklift or crane to pick it up. Chain & strap it down good and take the journey slow with lots of stops to make sure everything is tight. Also make sure the boards/skid underneath are in good shape, you don't want that giving out on the highway. Be EXTRA CAREFUL, that thing weighs more than either of you think
> 
> As for CNCZone you can post in the general area and the moderators will move your post if needed. Certainly the first post from someone getting a new machine is always welcome. Posts with pictures of moving stuff is even better.
> 
> ...


Thanks for the advice! I'll hopefully have updates this week on what happens. I'll update.


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## Crutches56 (Jun 29, 2019)

So I came up today and saw the mill for the first time in person. She's gorgeous. Really rough around the edges.... But I can tell she's got sweet spirit. . Here are some current pics. The rust on the table is far less than I thought. I was curious enough to try and move things. The x axis motor has a shaft you can grab onto, and we were able to spin it and move the whole table way easy. Only moved it back and forth about 0.060" each way. I'll clean it good before I do too much. The knee won't go up or down. The crank spins almost a full turn then binds, so hopefully my gib isn't ultra stuck/broken. I didn't check anything else beyond that mechanically. The spindle had a spindle wizard built in, but I might try and convert that. Have to research that a bit. It came with an old desktop computer and a stand that bolts onto the machine to hold it all. I'll be converting to just a laptop. Haha. The control box on the back...... I need opinions. Do I try and get it to work, or do I just scrap that and replace it with something more current? I have pics of the whole machine, the main motor, the stepper motor tag (3 identical motors for X, Y, and Z (not knee, that's still manual, but I want to get a power feed). 

We're taking his beat up trailer about 5 miles to a equipment rental center tomorrow morning. I talked to them, they said for $50, I can use forklift to move it. So we'll lift it up (my buddy has moved a lot of machines over the years), we'll drive out from under it. Then back my trailer under it, and set it down and get her secure. 

Advice? Thoughts? I'll post more pics and Info as it comes.


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## matthewsx (Jun 29, 2019)

For moving make sure to rotate the head and block it against the table. Go slow and take it easy, more straps and chains than you think you need, others probably have more/better advice.

As for the control box, you will probably end up tearing it all out but it's worth trying it as-is to see what it'll do if you can get the correct power to it. There may be parts you can re-use so don't throw anything away of course. If it were mine I would make a comprehensive plan on what parts are needed and the required specs first. Then you can look for used/surplus pieces that are suitable, you will have plenty of time while you clean and inspect the mechanical aspect.

Looks like a beauty, take your time to get it right and you will have a machine that will last a lifetime and you won't outgrow

John


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## Crutches56 (Jun 29, 2019)

Well the mill has made the trek across the mountain. We got his trailer tires pumped up and drove to the rental center. And in less than 5 minutes had it lifted off his trailer. Drove his out from under it, and backed my trailer under it. Tied her down. Stopped twice over the mtn to check the straps. All went well. She's now in my "needs some love" shed at my shop. I'll finish those outer walls so it'll be more protected. I'll pick it up and drive it into the shop in the next month and start de-rusting her. I picked it up with my skidsteer at the shop and drove it right Into the shed. (just to ease worry, we had wood blocks under the ram ways to protect them from getting hurt.)


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## matthewsx (Jun 30, 2019)

Right on, I should have known you'd be wearing a utilikilt

You might want to give these guys a call and see if their kit will work for you.





__





						CNC Controller for Bridgeport V2XT DX-32 CNC retrofit controls for Knee mills.
					

CNC retrofits for Bridgeport Boss CNC knee mills, upgrade packages for older Bridgeport NC CNC milling machines.



					www.centroidcnc.com
				




Cheers,

John


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## Crutches56 (Jun 30, 2019)

matthewsx said:


> Right on, I should have known you'd be wearing a utilikilt



Haha that is my machinist buddy. He's a stud, he's the one who gave me the mill. Knee high boots and a utilikilt are what he wears everyday. And that insulated coat.... On a 98 degree summer day... 

I'm going to start cleaning this week and see what her condition is.


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## P T Schram (Jul 1, 2019)

You've done well Young Jedi!

I agree with everything above. Block it in place. As you can't move the knee, I cant very well tell you to run the knee up to support the head, but otherwise you're on your way.

W/R/T the electronics, etc, start learning yourself on CURRENT State-Of-The-Art controls. I'm not in much of a position to contribute much there, other than to say this should be one of the easier updates as you have everything there, now just need to interface to modern computer hardware/software.

Yeah, I'm a little jealous!


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## P T Schram (Jul 1, 2019)

matthewsx said:


> Right on, I should have known you'd be wearing a utilikilt
> 
> You might want to give these guys a call and see if their kit will work for you.
> 
> ...


I missed the kilt part! I LOVE my Workingman's Kilt, but I'm forbidden from wearing it in the shop, apparently it's too much like shorts and shorts are forbidden as well.

The Snap-On man at the shop shared that bit, my kilt was costume for Snap-On Franchisee Conferences. They might not have known my name, but everybody there knew who I was-LOL


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## Crutches56 (Jul 2, 2019)

I started messing with things tonight after family went to sleep. I live about a mile from my shop, so I can sneak down here quick. With the knee not moving, I pulled off the felt wiper cover, it's cracked: has been over tightened. And the wiper itself is dead. No surprise there. The flathead adjustment screw on the gib is SEIZED. I filled the hole with wd-40 and in about 7-8 seconds it's gone, so it's going somewhere, hopefully that's a good sign. I'm going to let it soak overnight, then in the morning, I'll put my hand impact driver on it for 1 hit and see what she says. I talked to my buddy and he seemed to have a memory that this was a 1 part machine, so he actually never moved the knee the whole time he ran it... So he said it's been probably 15 years since this knee has moved.

I chipped the metal chips out of the T-slots tonight (flat blade screw driver and a hammer)... They were packed. The t slots were completely full. Now those are out and I started cleaning the table a bit. It's in great shape. I'll clean it up a bit more tomorrow in the light and take pics.

I plugged in the computer that came with this thing, and it works! Hahaha. Didn't expect that. I plugged it into my flat-screen I use for my security cameras, and the dang thing works. I figured you guys would get a kick out of this. On the screen, the jogs work, and I loaded a program the shop ran, and it ran through all the numbers in their g-code. Haha. I'm just watching it sitting here laughing. When the mill can get the right power to it (it's in my forklift shed right now), I'll plug the computer in and see if this thing will move it. Check out this computer and the DOS program...


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## matthewsx (Jul 2, 2019)

Nice, I'd make an image of that hard drive right away. Also copy the program off to floppy disk, if the machine works as-is it will give you time to plan the conversion to modern stuff.

John


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## Crutches56 (Jul 2, 2019)

matthewsx said:


> Nice, I'd make an image of that hard drive right away. Also copy the program off to floppy disk



Agreed, however... Where am I going to find a floppy disc?! Haha. I haven't even seen one in the past 20 years... I bet my parents have some stashed on their basement...... Time to go digging.


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## matthewsx (Jul 2, 2019)

Crutches56 said:


> Agreed, however... Where am I going to find a floppy disc?! Haha. I haven't even seen one in the past 20 years... I bet my parents have some stashed on their basement...... Time to go digging.



So, as a network admin here's how I would handle this.

1. Remove hard drive from this machine and make an image using whatever cloning software you like. You'll need a machine that can handle old IDE disks though, should be one at a thrift store nearby.

2. While the disk is still attached to the machine you're cloning from also copy the CAM program/s to the local hard drive and/or USB.

3. Try to get it working on the machine you used for cloning the original drive, old PC's are cheap/free and it's likely the software will only work on something close to it's own era. Running on a virtual machine is possible but probably not likely given the need to interface directly to hardware.

I wouldn't spend a whole lot of time on this but it's probably worth a few hours to preserve the original stuff. Even if you never use it there may be important things there like offsets for backlash, etc.

Cheers,

John


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## north1 (Jul 2, 2019)

Nix the WD40 and use PB Blaster instead.  For this type of application it will do a much better job of penetrating, loosening and lubricating.


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## Crutches56 (Jul 2, 2019)

north1 said:


> Nix the WD40 and use PB Blaster instead.  For this type of application it will do a much better job of penetrating, loosening and lubricating.


Totally agree, I'm a huge fan of ob blaster and Kroil for this type of stuff, but I ran out last week in the shop, and wd was all I had. Should be getting more today. Always appreciate the help!


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## markba633csi (Jul 2, 2019)

Does that computer have USB ports? You could copy everything to a thumb drive
Mark


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## Crutches56 (Jul 2, 2019)

markba633csi said:


> Does that computer have USB ports? You could copy everything to a thumb drive
> Mark


I SO hoped that! This computer was made before USB was twinkle in Ajay Bhatt's eye...


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## matthewsx (Jul 2, 2019)

Crutches56 said:


> I SO hoped that! This computer was made before USB was twinkle in Ajay Bhatt's eye...


Yep, I figured as much. Write down or photograph any configuration pages you can get to in the DOS program, then figure out how to clone that drive.

Or, don't worry about it as you'll be retrofitting everything anyway

John


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## markba633csi (Jul 2, 2019)

Oh darn. I thought I spotted some on the front panel- rats


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## Crutches56 (Jul 3, 2019)

So Im pricing a full setup to completely update the electronics. Motors, drivers, control boards, power supplies etc... I'm a newb so if I come across as dumb.... I am. 

The motors on it are 2.1v 8amp motors with a holding torque of 840 Oz in. I'm looking at setups that have 1600 oz in of holding torque, with 5v at 6 (ish) amps. The motors themselves look smaller, but torque is torque. There is no reason those motors wouldn't do well right? If someone asked me that, I would say "absolutely they're fine", but where I'll be coughing up actual money, I want to be sure. Also I plan on removing one to check the what shaft these have so I can replace it correctly. 

This is the setup I'm thinking. Give me thoughts, opinions, disclaimers..... 

3 1600 oz in (possibly 1841 nema 34, price is similar)  stepper motors with drivers as a package deal. 6.2 amp 

3 Power supplies: 60v 8amp

6-axis USB ethernet control board compatible with. Mach 3

I want to get Mach 4, will it be compatible with that control board? I don't know why it wouldn't be. Just covering bases. 

Brett


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## matthewsx (Jul 3, 2019)

Crutches56 said:


> So Im pricing a full setup to completely update the electronics. Motors, drivers, control boards, power supplies etc... I'm a newb so if I come across as dumb.... I am.
> 
> The motors on it are 2.1v 8amp motors with a holding torque of 840 Oz in. I'm looking at setups that have 1600 oz in of holding torque, with 5v at 6 (ish) amps. The motors themselves look smaller, but torque is torque. There is no reason those motors wouldn't do well right? If someone asked me that, I would say "absolutely they're fine", but where I'll be coughing up actual money, I want to be sure. Also I plan on removing one to check the what shaft these have so I can replace it correctly.
> 
> ...



I'm far from an expert but why change the motors? I doubt Bridgeport undersized them from the factory and as you pointed out they are the most expensive piece. Also they're steppers already, right? So no advantage in changing to bigger steppers if you don't need the power to make your cuts. 

A new control board and drivers are going to make life easier but check the power supplies you already have, most of the modern stuff operates in a range of voltages so if the power supplies on the machine will work there's also no advantage to replacing them.

The exception would be if someone has already engineered a complete system that will bolt right up, then it might be worth replacing everything. However, with that fine old iron Bridgeport probably supplied some fine old electrical components as well. Getting pieces that are as high quality as what's on there could be prohibitively expensive. Taking the time to evaluate what you already have is just a matter of spending a few hours with a meter and a pencil.

As for the control board I can't really say without a part number. Lots of folks seem to be happy with the Mesa Electronics stuff, they're here in the states so I would give them a call. They've probably helped people with your exact mill and can steer you in the right direction with all the components they have.

Cheers,

John


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## Crutches56 (Jul 6, 2019)

Alright... Lots of good updates! It works! The cnc controls, motors, everything works..... I lifted the mill up again and built a tough pallet for it. 3/4 cdx plywood on top of a pallet built for concrete bag mix. Tough. Then strapped the mill to it. Now I can drive it in the shop when I want to work on it, and go put it in the shed when I need the space to do repairs (again, I run an atv/small engine shop). I'm building another building eventually to house this, and it'll have a permanent spot, but that won't be for probably 6 months. I put power to everything but the 3 phase motor, and it all works. I de-chipped the table. And got the knee unstuck tonight found out the key on the knee crank clutch is sheared, and the actual clutch is cracked. But we'll address that another time. Got the spindle un-stuck, and can move the table x and y full length... It's awesome! I think I'll do a pmdx-424 control board, and use the existing drivers....


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## matthewsx (Jul 6, 2019)

Great news!

Don't fix what's already working, if you can get away with just a new control board you're miles ahead in having a working machine.

John


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## Crutches56 (Jul 11, 2019)

So we have all the heavy rust off the table. But this is what I'm fighting now... I can't get the spindle nut off! I have a few questions if you guys know... 
A: what spindle is this? (my guess is bt30?) 
B: it's holding an ER chuck, and that comes off, but the main black nut (knurled) will not budge. 

It's been soaking in pb blaster, and I've put a spanner on it, put the spindle brake on and pulled. And hit the spanner, but without going nuts, I want to make sure I'm not missing anything. I've been in touch with kennametal, and they said it should have 3 locking screws and you do things with them st certain points to lock this thing, but all the threads don't have bolts. Just half full of dust and junk. They finally said "use force to unlock it".... 

Before I start going heavy duty trying to loosen it up, am I missing something simple? 

Brett


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## matthewsx (Jul 11, 2019)

Drawbar?


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## matthewsx (Jul 11, 2019)

See if you can get an exploded diagram, that will tell if you have a mechanical issue or just rust.


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## Crutches56 (Jul 11, 2019)

matthewsx said:


> Drawbar?


There is no drawbar in it. I can see inside from the top all the way to the bottom. Confused on what I have!


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## Crutches56 (Jul 11, 2019)

matthewsx said:


> See if you can get an exploded diagram, that will tell if you have a mechanical issue or just rust.


This machine has been so modified, I don't know what to look up. The cnc conversion, I learned, was done by the last company who owned this. They did all of it themselves (my buddy helped convert it, but he said he doesn't know what the spindle is)


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## Crutches56 (Jul 11, 2019)

Also..... Check out the table. Scotch brite, wd-40, and mineral spirits have done wonders (along with hours of elbow grease)


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## matthewsx (Jul 11, 2019)

Crutches56 said:


> This machine has been so modified, I don't know what to look up. The cnc conversion, I learned, was done by the last company who owned this. They did all of it themselves (my buddy helped convert it, but he said he doesn't know what the spindle is)



Well, if you have the capability to use ER tooling you could leave it be until you have a better idea of what it is and how to take it apart. I'm sure someone on here will recognize the system and speak up eventually.

John


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## Crutches56 (Jul 13, 2019)

Updates: 
Table is looking awesome. Mostly clear steel across the whole top. There is pitting and rust in the low spots, especially where they sent a drill into the table. 

I was there until 1am last night going over wires and my plan. They have line voltage coming in to a transformer, which then feeds a bridge rectifier, which then hits a big capacitor, which then feeds nice filtered DC to all 3 driver boards. It works perfect, I won't change a thing. 

They have their 3 phase coming in (I don't have 3 phase) that hits 2 big contactors wired in parallel, which then feeds 3 phase to a breaker, which then feeds 3 phase to the spindle motor. I'll feed 220 to my VFD, which will feed 3 phase to my motor. So those massive contactors will go bye bye and be replaced by a smaller setup for 220 single phase. 

Heres the best updates:
I purchased Mach 4 hobby, and downloaded fusion 360 and have been learning them. They're awesome. I took drafting in college for 2 years before going to motorcycle tech school so it was simple for me to pickup. Then I bought a PMDX-424 smart BOB USB control board. This will interface directly to my current driver boards and allow me to run this Bridgeport with my laptop. 

IIts all coming together!! Thanks for all your help with this. I'm up to around $1,200 total in what I've spent to get this thing going, but that includes a 6" mill vise I bought, the board, Mach 4, etc... Everything.


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## rwm (Jul 14, 2019)

Could you use the existing 3 phase breaker to interrupt the output of the VFD? What happens if you cycle the VFD power as you describe? Does it restart where it left off?
Robert


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## matthewsx (Jul 14, 2019)

rwm said:


> Could you use the existing 3 phase breaker to interrupt the output of the VFD? What happens if you cycle the VFD power as you describe? Does it restart where it left off?
> Robert


Generally no switches between a VFD and the load. It’s easy enough to manage VFD functions from the CNC control board.


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## Crutches56 (Jul 14, 2019)

matthewsx said:


> Generally no switches between a VFD and the load. It’s easy enough to manage VFD functions from the CNC control board.



Oh right, I didn't mention: from pmdx, I also got their 407 spindle control board, which plugs into the 424 board. This will be able to control spindle speed from Mach 4 (407 board manages the vfd). My boards should be here this week, and I will be able to start wiring them up. I could possibly be running a program within a week or so!


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## Crutches56 (Jul 16, 2019)

So I bought the correct spanner wrench from McMaster, and gave the nut 2 good smacks... The taper tooling came right out. I've read other posts about this Erickson Qc30 tool holders. I've read you can buy the nt30 holders from grizzly and modify the flange thickness to make them work with this quick change, but i don't have access to a lathe. So 2 questions:
1: Anyone have any good sources to find these tool holders besides eBay? 
2: Anyone have any used holders laying around they want to sell? (or trade for atv/motorcycle parts haha)


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## Crutches56 (Oct 3, 2019)

First off, Thank you for all your advice and help. Our atv shop got insane and I haven't had time to breathe until last week. I pulled the mill in and fixed a ton of the issues. I got the gib loosened up (the adjuster screw was broken) the knee unstuck, the vfd functioning, the spindle turning, the vise bolted on, and chips thrown! Then I went down last night, and wired my new pmdx control board to the existing stepper drivers, and hooked it to my laptop, and I am how controlling it with Mach 4. Im a long way from knowing Mach 4 super well, but I can at least manually run the mill through Mach 4. The broken gib screw... I put some weld bead on it to build it up, then welded a nut to it, then turned it out with a ratchet. No damage anywhere. Phew. I need to install limit switches for all axes, but right now, I can run whatever I want (with caution). I do have 1 problem, and I'm not sure if it's vfd related or vari speed related (in the head). When in high gear, If I don't turn the vari speed all the way up, I can grab the spindle with my hand and stall it. It has no torque. Drilling with a 3/8 bit through 1/8 steel stalls it. Also if I'm not at high speed, there is quite a bit of chatter/noise in the head. My buddy said it was rebuilt fairly recently before it came out of service though. But my vfd was set up by me, and I have no idea what I'm doing with that. (cheap chinese vfd with no instructions). I plan on buying a better one as I dropped this one and the case shattered. But it functions for now. Check out the pics and videos. Any comments, questions, advice is welcomed!


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## matthewsx (Oct 12, 2019)

Great to hear you got it going.

Smallish


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## Crutches56 (Nov 30, 2019)

So here's a small update. I have the Bridgeport strapped to a heavy duty pallet, and when I want to use it, I just pick it up with my skidsteer and drive it in my shop, then when I'm done, put it back in the shed. It's a totally unconventional way of owning a Bridgeport, but it works. We are expanding our atv shop, and adding 3200 sq ft, which will allow me to have a dedicated machine shop area (current shop is only 1200 sq ft). I also just bought a 15x50 turnmaster lathe that I'll be able to put in the new shop.

I'm brought the mill in several times, and have actually been been able to do a few jobs with it. Modifying intake flange bolt patterns to fit a different cylinder head was one. I have some interesting problems though. I think my Z axis motor is dying. If I take a cut with a facemill across a piece of steel, and leave the stock or stop my x axis feed, then move it, my z axis moves. Either up or down, no consistency. But it moves up or down 5-15 thou. It's odd, if I do a solid feed with x, the z doesn't move. But again, if I stop the feed, if moves, or leave the stock, and come back on, different height. Also, the z motor has a whiny screech when you put power to the cnc setup, so I'm sure it's dying.

Also, I'm sure I have problems in my head. (Bridgeport head). My head will always have problems. I can stall the spindle with a 0.050" depth of cut with pretty much any end mill. And the chatter and noise up top is horrible. When I have a solid spot for this thing to live, I'm going to break down the head and rebuild the whole thing. 

My lathe is missing its chucks. Anyone have a D1-6 mount chuck they want to sell? I've priced new ones, but figured I'd check here before I buy one. Looking for a 3 jaw and 4 jaw.


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