Acornsix yaskawa sigma2 issue!

[supermaxcnc]

I need some help!! I just completed a acornsix with yaskawa sigma2 drives. I set up the drives according to tb297 which is close to sigma2 although mine are 16 bit encoder so i set dividing ratio to 32768 over 1024. I have perfect motion in jog mode and mdi commands i have confirmed commanded distance vs actual is perfect. But when i run the machine with. Program its making extremely out of round holes almost 40 thousands out. And the z axis is losing position and regularly 100 thousands lower after each cycle start very strange.. any insight appreciated

[supermaxcnc]

report attached

[tblough]

If the motor drives are not showing errors for list steps, then it is probably a noise issue. Try re-running your program with the spindle off.

[supermaxcnc]

i had feeling it could be noise... i will try thanks

[supermaxcnc]

you were correct it doesent lose Z height with spindle off .... so now what lol

[tblough]

Make sure your spindle motor wires are properly shielded. Separate the spindle wiring from control wires and if they have to cross, make sure it's at 90 degrees.

[supermaxcnc]

Well now i cant get any motion now at all theres no faults. The acorn is sending pulses and the yaskawa are indicating run mode but no motion. Nothing has changed.

[cnckeith]

i would review the parameters set in the yaskawa drives, what command mode do you have the sigma 2's in? if memory serves there are two step and direction modes

[cnckeith]

others have also used differential drivers for connecting Acorn/AcornSix to these drives and others like it to make use of the noise resistant differential step and direction signal.

https://shopcentroidcnc.com/shop/cnc-ex ... out-board/

[supermaxcnc]

They were already working i also did another machine last year with same drives and its still running fine .... the differential board seems like a reasonable idea. Although just more money!