retrofit on EMCO PC turn 55

yesterday the last half were blank. Now they are there. Must be something to do with Windows7!
Sorry for the non issue.
cs

I received some questions based on this topic and I would like to address them here because I'm sure people here will have valuable input.
Here is a copy of the email....

Hi-
I'm looking around for a CNC lathe, and considering a used PC Turn 55. (For
example
www.ebay.com/itm/2000-Maier-EMCO-PC-TURN...&hash=item3cc6e1ca64)
I have some experience with lathes (~300 hours) and excellent technology
skills (I helped design a computer at the chip level, for example), but I
have absolutely no experience with modern CNC machines.

2 questions
1) What do you get out of a retrofit vs the original software? (I have no
idea what the original software does.)

2) How is it going? If you feel like the project is converging, I'm pretty
sure I could follow in your footsteps.

I finished this project a long time ago so parts of it may be a bit hazy. I do have a fair number of pictures that might help.

I did a retrofit because I didn't have any of the original Emco software and frankly didn't care to learn about it or the antiquated PC associated with it. I would also bet the original software does not have the features of LInuxCNC. I was familiar with LinuxCNC and it works well for me. I also wanted to use the emoc tool turret and I could find examples of other turrets that I figured I could adapt. That is a topic covered in another thread.

My conversion consisted of gutting all the old electronics including the odd 5 wire stepper motors. I used some nice stepper motors from Keling that work very well. I used a Gecko G540 for the control even though it has two drives that I don't need (it was still the cheapest solution). I reused the existing 24V power supply because it was adequate and I needed 24VDC for the turret motor. I used a Teco VFD from dealers electric and interfaced it to the G540 for spindle speed control. I removed the big red box on the back and scrapped it (I did save the yellow plate and cut it to size to make a bottom for the grey part of the cabinet. I put all the new electronics in the back of the grey cabinet.

My system requires 2 parallel ports in order to have enough I/O for the spindle encoder and tool turret.

If you do decide to convert a PC Turn55 we can address the conversion in stages.

I noticed that the current version (the Concept Turn 55) lists 52mm as the maximum turning diameter in spite of a 65mm center height. Is the PCTurn 55 indeed limited to such a small size?

It looks like I will be doing the conversion. The one I bought is missing the PC and the card (though it has the software.)

What kind of motors did you get, and did the slot right in where the old ones were?

What did you do about the turret?

Roughly how much would it cost if you did it again (you don't have to be exact.)

that looks a nice machine that andy even supplys a molex connecter and sata hdds from (the 12volt input) no need for a psu at all just a nice compact 12v din rail psu

I didn't even try to use ANY of the existing electronics. I just didn't think it was worth the effort and I didn't have sufficient documentation to try it.

I bought Kelinginc KL23256-21-8B steppers. They are physically the same size as the original motors but I'm pretty sure they have significantly more torque. OEM max speed is 30 IPM but I run the new motors at double that and they will even go tripple but I don't think that is a good idea for a number of reasons. Also keep in mind the original motors are 5 wire motors and you may have trouble finding drives to run them. Another piece of important info is the original motors are NOT NEMA motors. The shaft is smaller and the mounting holes are spaced differently. I had to modify the mounting plates and drill out the pulleys to fit on the new motor shaft.

These motors in bipolar parallel are a VERY good match to a Gecko G540. I used the G540 because it is cheap and works very well. It has the VFD interface built in that you will need to control a new VFD to run the existing 3 phase spindle motor. Kelinginc has a excellent price on them as well.

I used the original 24 VDC power supply because I needed 24 VDC for the turret. I was a little concerned that 24 volts might not be enough for high speed stepping but it worked out fine.

The only items I had to buy were:
2 steppers at $30 each
1 G540 at $240
1 GE TECO VFD at $120 (from dealers electric ). I used a 1 HP FM50 with 120V input 240V 3 phase output.

I am using an old PC with 2 parallel ports. the second port is needed for the turret.

When I did my conversion, I was misinformed that the 5 wire motors were oddballs and not compatible with gecko drives.

I do not know the EMCO driver interface. I read in another forum that they are step/direction drives but EMCO refused to release any info on products they currently support. Frankly I didn't think it was worth the time to reverse engineer electronics hardware that is almost 20 years old anyway. What are you going to do when one of the old drives fail? Either pay a lot to replace it with more old hardware or do an upgrade. I chose to gut all the old hardware and install a G540. In the process, I remove the entire red cabinet on the back of the lathe and installed the G540 and old transformer in the lathe cabinet. I have less than 500 dollars invested for 2 steppers, a G540 and a VFD.

I wrote a component to control the tool turret. Most of the discussion is in another thread. I can post the code in that thread when jrkeat gets to that point in his conversion.

chuck

So I shouldn't have trouble running the original motors, as long as I don't mind the original slower speed?

As far as the computer is concerened, what are the constraints? For example, could I use on of my laptops and just buy a pair of USB-> DB25 parallel adapters? It has been 10 years since I used any version of Lunux, and at the time it was pretty finicky about hardware compatibility--I'm not sure if this has changed or not. I'm also not sure if come components meet real-time demands, while other don't.