# Emco Compact6 CNC lathe.



## mu38&Bg# (Nov 19, 2011)

I had been looking for one of these small Emco machines for a few months. They aren't too common, but turn up here and there. I was lucky enough to find one close to home last week on craigslist. The price was right and it didn't have a control which was perfect. After digging into it it looks like it had a fairly rough life. I am going to have to come up with a chuck for it. I was told it had some kind of manual collet chuck being activated by an air cylinder. The motor is a 380VDC shunt type, 6000RPM max. I'll have to replace it with an AC motor and VFD I still have to figure out if it's OK to run a 3600RPM motor at 6000RPM by increasing the frequency. I was fairly set on servo motors with Gecko drives, but am reconsidering. There are 5phase steppers in the machine and 5 phase drivers can be found. The biggest problem with this project will be getting the turret working. I'll be using EMC for control.

Greg


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## flyinghospital (Nov 21, 2011)

Hi Gary , 
if your using EMC then the toolchanger is quite easy to convert , their are 2 versions of the emco toolchanger , one using a dc motor and the other a stepper 
but either way , it's not too bad . 

i can help once you get to that stage if needed 

Dave


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## mu38&Bg# (Nov 21, 2011)

That sounds good. The guys on the Emco yahoo group made it sound like an impossible task. This is the earlier turret. The later turret is round, but I didn't know they changed motors at some point. This one does have the brush motor, but if one or the other is easier to implement that will be the deciding factor.

I did get all the cover panels removed. I'll have to get the bed casting off the frame to get this into my basement shop, then the fun starts. I did learn that running a motor at higher frequency is OK and just need to sort out what I can find, fit, and afford.

The Z axis ball screw has what seems like quite a bit of clearance. Are these preloaded originally?

Greg


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## mu38&Bg# (Dec 5, 2011)

Progress has been slow with this. I did find an IEC100 frame induction motor and with help from Ken I, decided that would be the best way to go. I already had a open loop vector drive that I just pulled from my manual lathe after finding a $45 AB Poweflex 4 drive for it. I decided not to use the steppers, and have some dc servo motors on the way. Finding chucks for this machine has proven to be difficult. I'll probably end up with a 4" Bison 5C chuck initially.

Virtually everything is off the machine now. This machine is a mess, covered in grime and chips. It came out of a shop not school like most of these. Documentation I found online appears to say that the ballscrews are preloaded, but I haven't looked closely at their condition yet.

Dave, any help would be appreciated. It will be a little while before I get to the turret, but am hoping to be close to operational by the end of the year.


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## flyinghospital (Dec 8, 2011)

your going with dc servo motors , how are you going to drive them ? , what about shaft encoders etc 
how are you giving positional info back to emc etc . 

toolchanger is not a major problem , iv'e just posted a toolchanger component on the linuxemc forum 
for the dc motor type , it's quoted for Denford Orac , but the emco is Identical i believe .


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## mu38&Bg# (Dec 8, 2011)

I'm going to start with Geckos and DC servos with encoders. I'm waiting for the servo to come in to very their specs, but they claimed to have 5000ct encoders. I already had the Geckos otherwise I may have done something different. I have a small mill using this setup and it has worked very well for me for years. By my math operating specs should be virtually identical to the original for speed, but with 0.001mm resolution. The only question is how much following error the Geckos will actually have in use. I jumped the gun and bought the stepper Mesa board for use with the Gecko's otherwise I might have tried to use EMC2 for feedback with simple servo drives. It looks like that is a much more expensive option though. I do have the original axis motors, but need to test them. The only reason I decided against Vexta 5 phase stepper drives is that I read they are low voltage so speed would be low.


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## rcfreak177 (Dec 16, 2011)

Hi Greg, 

Nice find, I too am looking for a similar machine. Emco, Denford, Harrison, or Boxford cnc lathe with an auto tool changer for a refit project. It seems that they are as rare as hens teeth here in Australia. I have been searching in the USA and UK as well.
Good luck withe the project at hand and if you do happen to see a similar type of machine for sale PLEASE let me know.

Cheers Baz.


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## mu38&Bg# (Dec 17, 2011)

It seems the Denford Orac, Hercules Compulathe, and Boxford are much more common in Australia than in the US. In the US the Emco are much more common.

The servos arrived and they do have 5000 count encoders with what seems to be two sets of outputs. I think they'll have plenty of torque for the job at hand and the EMC setup should exceed factory rapid traverse speeds. I'm testing PCs for EMC. I had good results with an old Dell GX-150 933MHz on my mill and have another I'll be using as long as the Mesa card plays nicely. I'm still sorting out getting the lathe cleaned before bring it in the house.

I've had no luck sourcing the TOS chuck I want. The only contact I found in the US is dragging their feet with a quote, and I got no response from TOS or a vendor in Germany.

Greg


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## mu38&Bg# (Jan 23, 2012)

I've managed to track down the lever actuated 5C chuck I wanted. The lathe is stripped down to the frame and awaiting some bright idea on how to clean it in the cold weather. I found a local machine rebuilder, but have not called asking for a quote. I might still drag it over to my father's and pressure wash the frame and bed casting outside in the cold, I just don't think that will get it clean. The grease on it is tenuous and barely washes off with any soap I have in the house.

I finally got a response from a tool vendor in Germany for the TOS chuck. Not cheap at something like 450USD with shipping, etc., for a 4" chuck, but they are supposed to be very accurate and with soft jaws it will probably be worth it.

The carriage and turret are in the shop ready to be cleaned and looked over.

Greg


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## mu38&Bg# (Jan 27, 2012)

We had a very mild winter day so I gathered the parts and hauled them over to my parent's house to pressure wash. The sludge stuck on this machine was tenuous. The detergent for the power washer didn't even touch it. I'm sure the balmy 39°F temperature didn't help. I ended up using a spray bottle and a half of Zep heavy duty citrus degreaser and scrubbing with a brush, all parts at least twice, blasting away the grime with the pressure washer in between. Now, I have some mostly clean parts sitting in the garage. I wiped the ways of the bed casting dry and sprayed them with Corrosion-X.

All of the screws I took out are covered in the same slime. Normally, I put them in the ultrasonic cleaner which does wonders for screws and hardware. However, the detergent I use in it did have much effect on some parts I already tried washing. I'll have to soak them in the degreaser first.

Tomorrow, I hope I get a chance to get over to the hardware store and pick up some lumber to put together a base for the machine. Then we'll have some pictures of the rebuild. I have a new spindle motor and drive, axis servos, gecko drives, Mesa Cards. I think I'm ready to go except for small stuff like limit switches and wiring.





Greg


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## coopertje (Feb 1, 2012)

Just discovered another Emco here. Nice work Greg :bow:

Have dun regards Jeroen


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## slowtwitch (Jul 25, 2012)

Hello, I have an Emco 120p, which is a twin to your lathe..just the colors are different I have converted it to all new modern electronics and installed new stepper motors and an AC 4hp motor for the spindle. 

Being a complete newbie at cnc, I never really found out what type of ball screws are in the machine. To find the tpi, I just turned the gear and counted how many turns it took to move 1 inch.

What are the specs on the ball screws??? Turns per?? How many starts??? 

I'm also kind of undecided on what my microstepping should be with this machine. Someone once told me that these machines do not like ipm's over 20. I don't know if that true or not. Hence, I currently set at 1/2. It runs, but , I don't think it's optimum for this lathe...maybe I'm wrong.

pete


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## Penprophet (Aug 12, 2012)

I got one today-   Do you have any advice on converting to modern electronics as mine does not have the controller.  Any suggestions who might have a copy of the manual??

Thanks.,

Mark


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## mu38&Bg# (Sep 4, 2012)

I found these two new posts here today. The ball screws are 5mm pitch reduced 2/1 from the motor. The specs claimed 1 micron resolution but this simply isn't true. 1/2 stepping with the original 5 phase steppers produces 2.5 micron resolution. If you install 2 phase steppers you'd have to run 5 microsteps to get 2.5 micron resolution and 280Ncm torque steppers to get similar axis thrust. The manuals spec the machines at 1200mm/minute (47ipm) rapids and that's probably fast enough for such a small machine. This thread gets into some info on microstepping. http://www.homemodelenginemachinist.com/f38/my-cnc-questions-thread-keep-eye-one-18074/

There is a yahoo usergroup for these machines both in their original form and conversions. My project has been lagging, but finally I have some need to get this machine running very soon. I did source the lever action manual 5C chuck that some of these machines were equipped with, but still have no jaw chuck. I should have bid on a couple 4" air chucks on Ebay that I let slide. The TOS chuck is still planned for a chuck with machinable jaws. If I run into a good deal on decent regular 3 jaw I might start with that. Most of my parts will probably use the collet chuck.

As far as converting, basically there is Mach or EMC2. Both have some options for getting the turret working. I think the best way to go with some sort of multi function breakout board as some of these amchines can support a variety of automated features, lube, air chucks, air tailstocks, etc.

Greg


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## LatheMaster (Sep 9, 2012)

Havent seen one of those machines in a long time . Had one in college back around 1989 . Small duty work but fun to learn on . Im thinking of converting a Grizzly lathe sometime in the future . I did a LMS mill a couple years ago . Look forward to your build . I have mach 3 for my mill . It works pretty good . I was told EMC2 had to be run on linux . Is this true . Heard its much better software .


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## RonGinger (Sep 9, 2012)

> I have mach 3 for my mill . It works pretty good . I was told EMC2 had  to be run on linux . Is this true . Heard its much better software .



Yes, EMC, now called LinuxCNC will only run on linux. 

As to better than Mach that is a topic of great discussion, about as useful as what I call a 'blonde vs redhead' question, one you are never likely to get an absolute answer for. In fact, both are highly capable systems, and I have never found a case where one will work and the other will not. 

I happen to use Mach and think its much simpler to use and setup than LinuxCNC, but thats probably because I have used Mach on several machines and have for several years. I found EMC way more trouble to setup than I was willing to deal with.


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## slowtwitch (Sep 10, 2012)

Great info, Greg...thanks


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## OldRon (Oct 17, 2012)

dieselpilot said:


> I did source the lever action manual 5C chuck that some of these machines were equipped with, but still have no jaw chuck. I should have bid on a couple 4" air chucks on Ebay that I let slide. The TOS chuck is still planned for a chuck with machinable jaws. If I run into a good deal on decent regular 3 jaw I might start with that. Most of my parts will probably use the collet chuck.


 
Hello,

I have an EMCO Compact 6P-CNC that has the pneumatic chuck. I purchased the machine to use for preparing the ends of ball screws. The pneumatic chuck does not have a through bore plus the 'through spindle' actuator draw bar is solid. That does not allow for long stock to be machined. The OEM pneumatic collet chuck has the same limitations. 

When time permits I will be removing the pneumatic chuck and actuator. Would you be interested in purchasing the components?

OldRon


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## mu38&Bg# (Oct 17, 2012)

Yes, I'm interested. What make is that chuck?

I just finished making room in my shop for this machine. I started a sketch for a base to put it on as I have none. Hopefully soon this process will continue.

Greg


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## OldRon (Oct 17, 2012)

dieselpilot said:


> Yes, I'm interested. What make is that chuck?


 
All of the components are original EMCO equpment. I tried to PM you first but you are not accepting mail so I made a public offering. Another person has expressed interest in purchasing the pneumatic chucking system so at this time you are #2.

OldRon


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## mu38&Bg# (Oct 17, 2012)

Oh well. 80 minutes too late I guess.

Greg


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## mu38&Bg# (May 14, 2013)

The Compact 6 CNC project is alive again. Today, I stripped the spindle and while the bearings are in decent shape, there was a lot or debris inside the spindle housing. I may replace the bearings while I have it apart, but I still have to pull the outer races from the casting.

Greg


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## DICKEYBIRD (May 14, 2013)

Greg I'm glad you've found the time to get back on the Emco & the time to document it as well!  I really like reading you posts.  Please keep it going.  What CAM do you plan to use?

Selfish guy that I am, I'm sad you're going with LinuxCNC as I chose Mach3 for my ORAC retrofit and would've learned a ton from you as you slapped Mach3 into shape.  It's all a struggle for me.

I have mine working but it's still early days. At the moment I'm hooking up a tach-generator as I have a 3/4 hp Baldor DC motor with a KBMM-125R controller (does reversing & dynamic braking)  KB says with a 7V/1000 rpm tach-gen I'll get 1% speed control over a 50:1 speed range.  I'm also struggling trying to get my head around setting up the tool table in Mach.  I have no ATC but will have 2 QCTP's and hope to be able to manually switch between 6 or 8 tools without having to re-reference each one.

I've bookmarked your site am really looking forward to see your progress!


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## mu38&Bg# (May 14, 2013)

I did tear down the spindle this afternoon. I'm glad I did as there was crap in there and the nose bearing probably wouldn't have made it much longer before failing.

CAM for lathe? Probably none, unless I get some complex parts to run. My old man has been hand coding lathes for 25 years. I do actually own a license for bob(crap)cad with lathe, but I've not used it. I happen to bump into a guy at NAMES last year who did a Compact5 CNC with a toolchanger who is local, so that will be a great help. I chose an AC induction motor with VFD as mentioned above. I do think this will work OK, but I don't know how deceleration will turn out. The AB VFD on my Clausing will stumble if I lower the speed too quickly. I haven't looked into the spindle encoder very closely yet. I do intend to do better than just one pulse per rev.

I did also track down a 4" 3 jaw Microcentric air chuck and tube for a grand total of 120USD. So, I'm glad I didn't rush and order that TOS chuck. Ebay yields great finds if you're patient.

I still have the bed and carriage of what was a central machinery 3 in 1, that was going to be my CNC lathe project. I was planning on QCTP for that. I still haven't figured out how to do manual tool change on the mill with LinuxCNC (actually still running the old EMC2.2xx). I just make separate programs. I did see a nice manual tool change program for Mach on youtube recently. I'll have to revisit the Linux CNC forums, it would save me some time. Tool table in LinuxCNC seems easy and I use it for radius compensation for thread milling.

It seems like tooling alone will be a fortune. I'm buying external holders when I find them cheap enough, boring bars seem expensive and lefties uncommon on Ebay, and have 3 ER16 collet holders already.

BTW, Some of the first parts I hope to run will be Cox related.

Greg


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## mu38&Bg# (May 14, 2013)

I hope I remember how all the sheet metal goes together. I didn't expect to let this sit for a whole year!


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## DICKEYBIRD (May 15, 2013)

dieselpilot said:


> BTW, Some of the first parts I hope to run will be Cox related.


Ahh, my sordid past comes up again.

Funny, I got my 1st machine tool in 2005 and the Cox engine/model airplane obsession fizzled out in less than 6 months.  I got the lathe to make a few Cox widgets but never did.  I still have it all stashed away in boxes.  My oldest grandson is getting old enough now that I should drag out some stuff & teach him to fly before long.

On the CAM side I've been using the Mach wizards for simple stuff but recently got really lucky and one of the Mach support forum gurus made me a killer deal on Dolphin v10 with the lathe dongle.  It's very powerful and will do all I'll ever need.  The Mach post processor is going to need some tweaking to play nice with my lathe once I get through screwing around with it.  Fortunately, the seller will help with that as there's no way I can do it.

It'll be really slick for you being able to use a spindle encoder with LinuxCNC when you start threading.  As you know, I'm stuck with 1 pulse per rev with Mach.  That's why I'm adding the tach generator to help stabilize the spindle speed.  I'm not even going to try threading until that's working.


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## mu38&Bg# (May 16, 2013)

Whether or not you'll be able to get away without hand coding depends on the precision required of the parts and the accuracy of the machine. My father gets jobs with CAM generated programs from the front office where the ±.0002" tolerance is much less than the bow worn into the ways and the backlash(after compensation) on the 15 year old lathe he runs. The CAM software can't account for the machine character. They program theoretical feeds to keep production high, but reality is often different. So he has to tweak the code by hand to take into account tapers and such to make the parts to print. The company doesn't keep up the equipment as much as you'd they they should to produce parts to the tolerance they quote for customers. In our little machines we'll have to settle for whatever the machine makes as I doubt the resolution will be there to fix a taper of a few tenths. I use my machines for prototyping work so I may be more critical. I'm sure maintaining spindle speed will improve threads in Mach. As you can see from my site I mess with rc engines quite a bit. Going to fly my diesel four stroke this morning.

The spindle bearings turn out to be standard off the shelf, even used as wheels bearing in some cars.

Greg


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## DICKEYBIRD (May 16, 2013)

dieselpilot said:


> As you can see from my site I mess with rc engines quite a bit.


Oh yeah, I've been lurking & admiring your work for years.  Very enlightening & interesting stuff you do.  I have some r/c day-dreams I hope to get around to at some point.

I've done some code tweaks as well on my other little cobbled up CNC lathe/mill and been known to "adjust" things with a file, emery cloth or whatever's necessary to make things fit.


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## kvom (May 16, 2013)

When I was learning lathe programming using a Haas, we could use the G7x canned procedures, so hand programming was relatively simple.  mach3 turn doesn't support these canned procedures, so multi-pass roughing isn't easy to code.  I've used CamBam for lathe for some simple parts.  However, it supports only turning.


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## DICKEYBIRD (May 16, 2013)

kvom said:


> mach3 turn doesn't support these canned procedures, so multi-pass roughing isn't easy to code.


Hmmm, have you used the wizards lately?  Maybe they've changed them??  I just ran a couple simple parts with a turned down spigot on the end of a shaft with a blended fillet and it worked great.  You tell it a finishing cut depth, roughing depth, fillet radius (and of course X/Y start/end coordinates and the other required info) press enter and whammo, instant G-code that rough cuts down to the finish point, switches feedrate and makes the finish cut beautifully.  I've used several other wizards in the past that worked well too.


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## kvom (May 16, 2013)

Never tried any wizards.  Thanks for the heads-up.


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## DICKEYBIRD (May 16, 2013)

You're welcome.

Mach comes with a quite a few useful lathe wizards and there are some more available free on the forum.  NFS has even more but they get $50 for a license.


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## mu38&Bg# (May 16, 2013)

Some careful searching in Ebay netted bearings with slightly better precision than standard at a very fair price. I'll move on to cleaning the turret or carriage while I wait for bearings.

Greg


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## DICKEYBIRD (Jul 13, 2013)

Hi Greg; making any progress?

I ran across this post from Sam (skunkworks) where he got his C5 working with Linux without replacing any hardware. Pretty smart fellow.  http://bbs.homeshopmachinist.net/th...-interface-with-linuxcnc-(no-interface-mods-)

Guys that can do that type of thing amaze me.


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## mu38&Bg# (Jul 13, 2013)

All the parts are clean and waiting to be reassembled. I purchased new bearings for the ball screws. I put myself in a corner by making a mistake during reassembly of the spindle. There is a part which needed to be put on the spindle before the bearing. Needless to say, I got ahead of myself and remembered the part just after the bearing cooled to the point I couldn't move it. The bearing sits near a shoulder and there is only a 0.8mm gap. I borrowed a bearing splitter which was too small. I tried to rent a bigger one, but the rental places didn't have them(they stopped offering them). I took it to transmission shop and nothing. Finally, I made something last week and got the bearing off, but have been busy with work. Slowly but surely.

That's nice work on that conversion. I was looking at something else he did recently.

Greg


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## DICKEYBIRD (Jul 13, 2013)

You gotta get that puppy up & running Greg so you can play with it!

I've made some more progress lately on my ORAC retro & cut my 1st CNC threads today.;D  16x1.5 mm in nasty hardware store CRS and the die screwed right on with hardly any effort on the 1st try.  What a feeling!

Gotta get some 'real' threading inserts and a holder when I get some hobby cash but it feels great to watch the magic happen with just a cheap-o brazed tool.  Of course if memory serves you've done thread milling so it wouldn't be as exciting to you to do CNC lathe threading.


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## mu38&Bg# (Nov 12, 2013)

This project isn't dead yet. I've been very busy with work and recovering from hernia surgery. I really should get all the enclosure parts picked up off the garage floor and so I can put the other car in. I also found a small piece broken off of the bearing cover on the spindle housing. It's part of the weep slot of the labyrinth seal. It's probably not a big deal, but I do have to decide if I'll make another before reassembly. Doing it later means a complete tear down to where it is now.

Greg


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## mu38&Bg# (Apr 25, 2014)

I guess I should post an update. I'm in the process of reassembling. The spindle is done and mounted. The new spindle motor is mounted. Turret is disassembled, and partly cleaned. I'm trying to decide what to do about the putrid yellow. I'm not sure if a rattle can paint will hold up to coolants. I might check with a place in town to see what it would cost to blast and paint the sheet metal. Some photos are on my Emco Compact 6 page.


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## mu38&Bg# (Nov 24, 2014)

Progress has been slow. I have cleaned and reballed the ball screws and reassembled the Z axis. I also made a print for the "old style" turret plate (disc) for somebody who had a machine without one.


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## rcfreak177 (Nov 25, 2014)

dieselpilot said:


> I'm trying to decide what to do about the putrid yellow. I'm not sure if a rattle can paint will hold up to coolants. I might check with a place in town to see what it would cost to blast and paint the sheet metal.



I went with sandblasting and powder coating, came up like new and cheap as well. I think from memory it 100 bucks for the lot.


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## mu38&Bg# (Dec 12, 2014)

If I want to get this up and running before spring I'd have to take it somewhere for paint. It's going to cost more than 100 dollars though. I might have to buy gibs for the X axis, but I'll try lapping what I have now. ~62USD each isn't too bad. I did find a Rohm jaw chuck, but now I'll have to come up with an actuator. I got a 5C adapter with it, but it doesn't fit my machine. It must be for the larger spindles. I'm thinking about building the pneumatic cylinder. The section view in the parts list looks simple enough, but it would still be a lot of work.

Greg


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