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Motor drive pulses
« on: December 13, 2013, 08:38:36 AM »
New to Mach3, but not machines and electronics
My old Mini-mill steppers need 4 milli second drive pulses, but Mach3 defaults to 15 micro seconds, and motors do not respond.
Port and pin numbers are set up correctly, verified by LED break-out plug and oscilloscope.
Is there a software/set-up fix to lengthen the pulses?

Offline Chaoticone

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Re: Motor drive pulses
« Reply #1 on: December 13, 2013, 08:48:36 AM »
Enable sherline 1/2 pulse mode in Config. ports and pins, port setup. I think that will fix you up.

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Re: Motor drive pulses
« Reply #2 on: December 13, 2013, 10:05:50 AM »
Thanks Brett. That made the pulses 40 micro seconds, will test on the mill later (not near the machine now)
Re: Motor drive pulses
« Reply #3 on: December 17, 2013, 10:36:08 AM »
Brett, the motor pulses are still too short (40 micro seconds, which extend out to 1 milli second on the control board). If there are no other software settings, then I suppose I will have abandon Mach3 or else get into the electronics and do a hardware mod on the control board. ???
Re: Motor drive pulses
« Reply #4 on: January 23, 2014, 12:53:48 PM »
Ended up modifying the original old Minitech controller by adding a small circuit board with 3 monostable pulse generators to lengthen the 40 micro-second motor pulses to 4 milli seconds. Used a conventional circuit configuration with 555 IC timer ICs. Worked just fine.  All parts are available at Radio Shack, or your favorite supplier.
 The original circuit board seems to be the same as made by Minitech, but I have no original diagrams to go by. However, I have made a drawing of the whole controller, including the added monstables. If you would like a copy, email me at AG4ZA@ARRL.net for an electronic copy.