Emco PC turn 55 upgrade..

Hi Guys,
finally got the time and space to start work on this project more seriously. The lathe I have is the 'emco pc turn 55'. This machine is unfortunatley quite different from the 'emco compact 5'. I have opened the machine up and am posting pictures in the hope that someone may find them useful or choose to pass comment. The machine actually appears to be quite well made for what it is. Data connection from the old controlling pc is via a serial cable. I am thinking that is simply used to transfer G-code (GE Fanuc series style) file to the machine which stores this and does its thing. As far as I am aware it is all working however the pc is from around 1998 and I can't bear to mess about with it (the old crt was binned as I found it to depressing to look at). The machine was demoed to me and I remember it being with a windows dos prompt. Much better if I can drive it with LinuxCNC.

So here goes - Step one - get rid of the old electronics and start new? - is any of it useful?

cheers, J

Step one - get rid of the old electronics and start new?

All depends how much money you have to throw at it.

If I were you I would try to do what skunkworks did with the Emco 5.
The trouble with Emco is that they are all proprietary boards, 4 phase unipolar steppers etc.
If you don't use their drivers and motors, you pretty much strip out everything and start again, with all the associated cost.

I did something similar with a Boxford lathe, located the step / dir connections, limits, home switches etc and wired up to a BOB and drove from Linuxcnc. That was more straight forward because they were bipolar motors, but Linuxcnc can drive unipolars and I would be amazed if the settings skunkworks ended on do not work with yours.

If you cannot do that, all you have spent out on is a BOB you may need anyway.

Second choice, I also would go for powerfull steppers with a high voltage PSU and drivers over small servos.
Less cost and complexity and probably better suited to the machine.

Try contacting Sam directly, I am sure he will help if your stuff looks similar to his

regards

Hi Arceye!
Unfortunately the boards are completely different. The motors are 5 phase.
Think i might have to swap them and the controller boards out!

Any recommendations for good brand nema 23 stepper motors that i can drive
With (is it?) the mesa card combo?

Thanks, J

Mech wrote:

Hi Arceye!
Unfortunately the boards are completely different. The motors are 5 phase.
Think i might have to swap them and the controller boards out!

Any recommendations for good brand nema 23 stepper motors that i can drive
With (is it?) the mesa card combo?

Thanks, J

Due to patent/licensing issues, only a couple companies were permitted to make
5-phase motors and drives. That would be Berger-Lahr and Oriental Motor/Vexta.
See if there are some super Vexta driver boards in there. These can usually
be configured to take step/dir, although some versions only take step up/step down
pulses. A simple device can convert step/dir to step up/step down if needed.
5 phase steppers are actually QUITE amazing, and outperform most 2-phase
stepper motors by quite a bit, both in power vs. speed and in much less
resonance trouble.

Jon

Hi Jon,
thanks for the info. I did a bit more reading and you are quite right. The 5-phase steppers should work well. Seems a shame to swap them out. I also looked more at the control boards in the machine. It is all quite well made but emco specific. There are a couple of programmable memory chips on the stepper driver board, the main control board has 3 or 4 xylinx chips on it and their is a vfd board for the motor and encoder - much more sophisticated than the emc compact 5 machine boards and all driven with emco logic, it would take some work to reverse engineer this although I am sure it is possible. Communication with the pc is via an RS422 pci card which communicates with the winnc software. I called the emco company and there is a software 'upgrade' available. When I get this info for interest I will post it up. The other alternative if I was to keep the existing motors would be to purchase Berger Lahr d450 stepper driver cards (I or 2, I have not examined this in detail) I am thinking I could use these to communicate with the steppers and hook them into the mesa card - however they are not cheap....

I wait for emco to come back to me with the software upgrade price - that will be the first step in the decision process and hopefully of use to someone else.

cheers! J

[quote="james-mech" post=43914The other alternative if I was to keep the existing motors would be to purchase Berger Lahr d450 stepper driver cards (I or 2, I have not examined this in detail) I am thinking I could use these to communicate with the steppers and hook them into the mesa card - however they are not cheap....
[/quote]
You can often find Vexta 5-phase stepper drivers on eBay for about $20, last time I looked
(which was a while ago).

Jon

You can find the 5 phase steppers, sure, but not the 5 phase driver cards..

james-mech wrote:

You can find the 5 phase steppers, sure, but not the 5 phase driver cards..

I typed "vexta driver" on eBay and got 884 items. I saw a number of the smaller drives in the
$25 - 40 range.

You will not find any Berger-Lahr stuff, they licensed the patents to Oriental Motor and
stopped producing under their own name, I think.

Jon

Hi Jon,
you are right - thanks. Quite a few possibles there on that search.

Am I right in thinking I can plug one of the vexta drivers into a mesa card combo and go from there?

As a 'for your information' for anybody who comes into the same situation ie wishing to use an older emco PC turn 55 with a modern version of windows and upto date winnc software emco came back to me today after I contacted them. They only want 1900 euros to provide me with a new main controller card that will hook up to windows xp and onwards. Oh and they want 1000 euros to come and plug it in... - not recommended to plug it in yourself, lol... - how reasonable of them!

Looks like that option is out!

thanks, J