Emco Compact6 CNC lathe.

[mu38&Bg#]

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

 

[flyinghospital]

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

 

[mu38&Bg#]

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

 

[mu38&Bg#]

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.

 

[flyinghospital]

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 .

 

[mu38&Bg#]

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.

 

[rcfreak177]

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.

 

[mu38&Bg#]

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

 

[mu38&Bg#]

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

 

[mu38&Bg#]

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

 

[coopertje]

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

Have dun regards Jeroen

 

[slowtwitch]

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

 

[Penprophet]

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

 

[mu38&Bg#]

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

 

[LatheMaster]

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 .

 

[RonGinger]

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.

 

[slowtwitch]

Great info, Greg...thanks

 

[OldRon]

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

 

[mu38&Bg#]

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

 

[OldRon]

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