Finally succeeded to replace NOVOSUN with traditional LPT breakout board and find older computer with LPT.
Now index works OK and rpm in MACH3 are stable.
So, I have used threading wizard and try to cut threads.
Threading starts, but only few mm moving is smooth and then starts to vibrate. Also return is not smooth.
Next pass starts also smooth, but starts to vibrate after few mm.
It's strange that speed- feed rate in MACH3 shows 0,75mm but programmed pitch is 1,5 mm
Also this feed rate varies from 0,72 - 0,78 - it's not stable - rpm in MACH 3 is stable and doesn’t change during threading.
Also cut thread has ~0,75 pitch.
Pulley ratio is set to 1.
What could be the problem? Any idea?
Thanks