Graham,

the motor controller is the original Gemini. I'm controlling the speed with dc derived from a V to F convertor chip (LM2197). The direction uses the original reversing contactor driven from 2 D2W202F solid-state relays.

I designed my own breakout board, which works fine, but I have found that some printer ports won't drive all the optos. I'm going to add some extra drivers to make it a bit more universal.

Thanks for the motor info. I thought it might be something like that from my measurements on the old unipolar drive. They don't even get warm at the moment, so I'll move it all up a notch.

Tony

LM2197? I cant find any reference to that on the web. Is that a valid number?

Graham.

LM2917N-8

A national device - got one in my hand.

Tony

thanks Tony,

Graham.

Tony,
You asked:-

"What state is your TCL in? How much rebuilding did you do? I've now replaced all the electronics except the Spindle motor & drive, the axis steppers & the PSU. Having just replaced the axis drivers with some from ARC-EURO, I'm having some fun trying to decide what current to set on the drives. The motors are the originals, one larger than the other, with no sensible ID. I've got them set to x 1.8A, z 2.1A at the moment, but I suspect they should be higher.
Spindle motor control with the Gemini Drive & solid state relays works fine."

I replaced the round steppers with square NEMA 23 2.5 Amp ones which are MotionKing 1.1 Nm. The drivers I used were 3 Amp 30 Volt £30.00. The BOB was CNC4PC C10.
This setup would run at 1.8 m/min for a G00 move but would stall if pushed any higher. In order to have some reserve power, I am now fitting 2 of Gecko's 203V's and a CNC4PC C11G  and the first impressions are realy good. I was able to push Mach3 up to 45KHz and have a surplus of torque, up from 0.3 Nm to 0.8 Nm at cutting feed rates, measured on the end of the ballscrew. The stepper is now running at 1350 rpm max, about 2.5m/min on a G00 move. I am still playing with this setup, so no final figures yet.

The original interlocked fwd/rev contactors are still fitted but I have not needed reverse yet, though I do have a small tapping head to try. My Gemini failed, so I replaced it with a SMC-00 from www.beel.ca. This drives the Lenze DC motor and provides plenty of cutting torque. The C11G will enable Mach to control the spindle speed and fwd/rev eventually.

Like Graham said, just push the amps up until the steppers run hot, then back off a bit.

Hope this helps,

Ian

Graham,

My "interesting" code would probably make Art cringe. He has provided all sorts of toys in Mach3 and I didn't use any! Not really worth it for simple, short runs.

Regards,

Ian

Ian,
thanks for the code - it all makes sense now. I've even run it and cut a part in PVC. I did have to alter it to suit my axes, however. My x gets more positive as the cross slide moves up - I think yours must be the other way round. I also altered line 100 to a G01 move. With my current motor setup the code takes 35 secs to run, which is not too bad I think.

Tony

Tony,

Well done! Have fun and keep us informed. Gecko's on the TCL in another thread.

Ian