Emcoturn 120P

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rcfreak177

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"YAAAAAAY

I found and purchased an Emco cnc lathe.

I managed to find this unit on Ebay, I do not know if it works or not yet and still have to arrange freight to get it from the USA to Perth Australia. If the unit is not working I will either repair it or convert it to function on the Mach 3 platform. The current operating system is Emcotronic T1. All in all I have a quality solid base to begin with.

Accessories include the operators and maintenance manuals, Pneumatic collet chuck and tail stock. Coolant tank. I will have to fit 3 phase power to my workshop as the rotary phase converter is not included .

I have a lot to learn about this type of machine but am sure I will figure it out.
Once I have the machine in my possession and tested I will post an update.

enco120p1.jpg



enco120p.jpg



Emcoturret.jpg


Emcocolletchuck.jpg


Cheers Baz.



 
I saw that listing. Are you able to get 380V 3 phase power? The transformer sold with these machines in the US took 220V 3 phase to 380V and had several taps so you could balance the phases and get the exact voltage required. The original control is very picky about input voltage.

I'm ready to start putting my Emco back together.

Greg
 
G,day Greg,

I plan on getting a 415V 3 phase power supply to my workshop and was planning on using a 415V to 380V stepdown transformer between the supply and machine. I still have to source one.

I have been following the build on your machine very closely, I cant believe how well the machine guards cleaned up, It is looking good so far. I see you are using servo motor with encoders, from what I have read up on servo's are very smooth running and much quieter than steppers.

Baz.
 
I understand the 220 to 380 transformers are very expensive here. So, if you find one without, you just retrofit. I hope you can somehow test it before spending on a transformer or converter.
 
Hi Baz,

Congratulations on your purchase! Its a great lathe, I have a 120 too and I love every bit of it. Mine came from a technical school and was hardly used. The paint inside near the 3 jaw chuck is hardly scratched. I purchased mine without the T1 control unit and main motor. This unit might work but is outdated. You can only transfer the CNC code over a serial link or program it directly in the T1. I prefer to have it on Mach3 for example.

Since I just had the mechanics as a start I purchase 2 Berger lahr 5 phase stepper drives, a 2.2KW AC motor and a Flux-vector frequency converter. The performance is more then enough using the original stepper motors, speed is nice but the dove tails are not designed for very high speeds. Therefor servo motors do not make so much sense to use on these kinds of machines, they are optimal for machines having linear guides. Total conversion costs were about 750,- euros in components.
Emco did something smart with there stepper construction. On the spindles for X and Z axis there are induction switches and indexing plates. They were able to detect missing pulses in case of a stepper stall. I did not dig into this in detail but I am thinking of designing some interface to detect missing pulses, in principle it just takes a digital counter, feed the program pulse to up count and the machine pulse to the downcount pin. Stop the machine when the counter value exceeds a preset value.

If you are interested I can post some pics from my conversion, I do not want to "take" your post.

Regards Jeroen
 
Hi Jeroen,

I am not sure if I will need a 230v to 380v three phase step up transformer yet.
I have 415v three phase power and may need a step down transformer to 380v.
Do you know the maximum input voltage for one of these machines?

I understand the system is very outdated but for some crazy reason it appeals to me and was hoping to get it working.

I guess if it is too much of a challenge I will take the same route as you have and retrofit it. I have a few spare electrical parts from previous cnc conversion I have done on my mill and China import lathe which both run Mach3.

I would love to see some pics of you'r machine, Please do upload them.

Cheers Baz.
 
Hi Baz,

The machines are designed for 380V. However, in Europe we are increasing the voltage step by step to have 10% more. Many machines will run on the higher voltage, however its not healthy in my opinion. This will wear much quicker when running on a higher voltage. I have never seen the original electronics of the 120, but knowing Emco the main transformer in the machine must have different connections. The standard is 380V and the are most likely pins with or the text +10%, +15% or with the voltages written down. The conversion is nothing more then swapping the wire from one pin to another and you are save. I had the same issue on my Harrison trainer recently and did above.

In my opinion its is better to convert the machine straight away. The electronics are at least 20 - 25 years old and every day that they keep working you should consider yourself lucky. When it brakes down its difficult to locate the error and finding the spare parts will be complicated and most of all expensive! In the end you will convert it anyway, so why spend the time in learning the T1 when it is just temporary?? But as said, this is just my personal opinion, everybody should do whats best for them.

Below some pics (hope its not too much :-[ )

Machine shortly after arrival in the shop

IMG_2349.jpg


IMG_2350.jpg


Mounting the new 2.2KW AC motor. The shaft of the motor was too small, I made a sleve and new spline

IMG_2355.jpg


IMG_2374.jpg


IMG_2376.jpg


A look inside the turret. The operation is quite simple, it rotates freely in one direction and it has a mechanical lock in the other. The trick with locking is to use a PWM current limiter to not burn the motor (24VDC).

IMG_2347.jpg


New electronics to control the 120

IMG_2340.jpg


IMG_2341.jpg


IMG_2342.jpg


IMG_2357.jpg


IMG_2351.jpg


Main spindle encoder and interfacing it to a PC. Replaced the original disk with one having just one slot. OH on the connector is the high lightswitch, OL is the lower one.

IMG_2371.jpg


IMG_2372.jpg


IMG_2474.jpg


Added a 15" touchscreen

IMG_2382.jpg


IMG_2383.jpg


I do not have pictures of the machine finished, however I have a movie of the machine up and running (sorry for the poor video quality..)

[ame=http://www.youtube.com/watch?v=ME8128i2Yp0]http://www.youtube.com/watch?v=ME8128i2Yp0[/ame]

Hope above helps a bit and if something is not clear let me know.

Regards Jeroen
 
Very nice, I probably will take the advice you give, Thank you.

I have to go away to work for 3 weeks, leaving in about 8 hours from now.

I will chat to you again when I get back. Thanks again.

Baz.
 
Ok. send me a PM when you are back, I do not keep track of all the posts overhere, very but to much to follow all!

Have a safe trip!

Regards Jeroen
 
The only thing I know about power for these machines is what I read online. Many people have issues with the quality of power and the spindle control. It will error is the power is not within spec. Some people could only run their machines when the neighborhood wasn't too loaded, or they had to move the transformer taps on a regular basis to get the machine running. There are still quite a few of these running on the original control, but most get put out to pasture when the quote comes for replacement spindle or servo drives boards.

I'm doing essentially what Jeroen did with a new 3ph motor. I picked a IEC 100 motor so the shaft and mounting would be the same. I would have just kept the steppers if I didn't have the Gecko servo drives already and I already have experience with the Geckos and servos. Mine will be a little faster , maybe 1800mm/min rapid, but I'll have 1 micron resolution if that makes any difference (the original spec says 1 micron, but working out the math on the motor, reduction, and ballscrew it's 2.5 microns). 5 phase stepper drives are not common but can be found mainly from Vexta. If you replace the motors with 2 phase steppers, you'll have to do 5 step microstepping and size motors for 280Ncm to achieve the same resolution and torque as the original, but rapid speed will be reduced unless your computer runs pretty fast.

I'm hoping to use the original spindle encoder to have rigid tapping.
 
Makes sense to me Greg. Related to the original encoder, it did not work with Mach3 in my case, the ref slot was too small giving problems at higher rpms (max 4000). With the new disk it works very well and it is easy to make.

Just out of curiosity, how do you achieve an accuracy of 1 micron? I think that the backlash in the spindels is much more then this. For me a repeatability within 0.01mm is more then acceptable for CNC, therefor having a stepper resolution of 2.5 micron is more then sufficient.

Regards Jeroen
 
Not accuracy, but resolution. My servo motors have 5000 count encoders, but I'll be multiplying steps by 2 to keep the speed up so will see 2500 counts per rev. I don't know if it will be of any benefit. The machines are said to be accurate, but I'm not sure how accurate. I intend to use mine for some production work, so adding a small tool offset, I'd like to know that the machine could actually respond. It can be helpful when trying to remove tapers in parts due to worn ways. My ballscrews feel OK, but I'd replace them if they turn out to be a problem. I know were talking miniscule amounts here, but I was surprised to find that Emco claimed 1 micron resolution when the hardware was actually only capable of 2.5 micron. I have 2 micron resolution on my little CNC mill and would rather see more when using tiny tools. I've not made anything that needed it, though. I'm going with EMC2 and Mesa cards, but I'm unsure yet whether the spindle encoder will be provide too much data.

Greg
 
Greg, I re-read your post and you are absolutely right. One can never have too much resolution, in that case the final accuracy is determined by the weakest chain. I cannot help you with exact figures on accuracy, all I know is that mine repeats within 0.01mm when making 20 pieces after each other. I state within 0.01 because thats the accuracy of my caliper but in fact all 20 pieces where identical. I do not have any backlash compensation enabled. These machines are constructed very well and accurate made. They also were not very cheap!

If you have the autolubrication pump on the machine, let it grease the guides every 10 minutes. I believe better a bit too much the too little.

Good luck with your machine, looking forward to your progress.

Regards Jeroen
 
Hi guys, ive just purchased a emcoturn 120 lathe and need some help??? i have it in my unit and i only have single phase power and the machine is 3 phase. Can anyone tell me what i can do to get this up and running??? ive been told of converters but dont know what ones to buy also generators. Please can someone let me know what i need to purchase as i really need this machine to be running.

Thanks in advance

kaine
 
I only know what I've read online. Practicalmachinist.com has a few threads and a couple regular posters that use these machines. It's possible to run it from a phase converter, but it has to be a very high quality unit. The machine is not tolerant of phase voltage imbalance as I understand it.

Being stuck with single phase myself, I didn't even consider the original control as an option.

Greg
 
I second Greg. It will be a lot of work to convert the machine to single phase, all transformers, coolant pump motor, lubrication pump motor etc are 3 phase.....

Not possible to get a 3 phase connection? The machine is worth the trouble of that!!

Regards Jeroen
 
"WAITING WAITING STILL WAITING"

Not long to go now, I have been tracking the ship my lathe is on (OOCL Atlanta) It is now in China.
Due into Perth Australia on 5/4/12, Then a week or so to clear customs.

I can't wait

Baz.
 
I know what you mean Baz although my lathe purchase isn't coming from as far away as yours!

I'm on pins & needles waiting to get my "new" Denford ORAC CNC shipped from the Detroit area to my shop in Collierville, TN...a mere 750 miles or so. I'm way past ready to start on it. It's a little feller, 8x16 based on an EMCO Compact 8. It's just the bed, carriage, spindle, ballscrews, motor mounts and base and is a low-time machine from a school. Perfect for my hodge-podge of parts waiting to go on it. ;D

My manual lathe is a middle 80's Compact 8 clone so all my chucks & tooling will fit perfectly. I got lucky! I'll start a thread on it when it gets a bit further along.
 
Excellent I am looking forward to the thread.

I have done a bit of research on the Denford Orac, from what people are saying out there they seem to be a very solid and good quality machine and are quite sought after.

Please do keep us posted with lots of pictures once you get under way.

Cheers Baz.
 
Yipeee!

My Emco lathe has arrived in Fremantle Port Australia, 3 ships later and several countries it made it all the way from Euclid Ohio, USA.

Now I have to wait for around 2 weeks for customs clearance and unpacking of the sea container then I will be able to pick it up, I can't wait. ;D

Baz.
 

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