Orac Stepper Motor Current Limit

[XJ5373]

Hi,
Just finishing off a conversion putting Mach3 onto an old Orac using Gecko drives and a CNC4PC breakout board.
What should the current limit be set to for the X and Z stepper motor drives? I see that the original electronics had 7.5A fuses in the lines between the torroidal transformer and the bridge rectifier but this seems rather high??

Thanks

Ian

[Andycnc]

Your original drives (CD20) would be 3amp. You may get a bit more cutting force and acheive higher feed rates with higher currents but this puts extra stress on the machine.

I'd keep to sensible traverse rates of perhaps 1000mm/min max I wouldn't go much above 4 amps drive.

My best guess would be that the fuses were over-rated to cope with short term transients (which can also occur at power-on).

[XJ5373]

Thanks vey much for this reply - 4 Amps it is then.

Now to get the tool changer working....

Ian