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SmartBOB controllers and dedicated accessories / Can't get accurate spindle speed for both drive gears using 424 with 407
« on: December 09, 2018, 03:59:52 PM »
Hello,
I've got a Precision Matthews PM-940M CNC in the garage that I've been slowly getting to work with a PMDX 424 and 407. The original nMotion controller was pretty bad and didn't work with Mach4, so the 424+407 seemed like the right route. After some trial and error, I've got all the motors and limit switches running properly, but accurate spindle control still eludes me.
I' believe I have everything wired in correctly, and I can send M3 Sxxxx commands, and get the spindle running pretty close to the commanded speed, however, I can only get the speed accurate with the potentiometer for one of the two spindle gears. I wired in an optical sensor to the spindle for an Index signal on Input C, so Mach4 is reporting the spindle speed accurately. I assumed that the PWM output of the 407 would adjust based on the Index signal but that doesn't seem to be the case. Am I stuck with a spindle only calibrated for one gear? Or am I missing something or perhaps going about this the wrong way?
I'm attaching some pictures of what seems relevant. If anyone can offer any help or insight, I'd really appreciate it. I really like the SmartBOB hardware and software, and this is the only thing that I can't figure out.
If it's any help, the VFD is a Delta VFD015E21A.
Thanks!
Malcolm
I've got a Precision Matthews PM-940M CNC in the garage that I've been slowly getting to work with a PMDX 424 and 407. The original nMotion controller was pretty bad and didn't work with Mach4, so the 424+407 seemed like the right route. After some trial and error, I've got all the motors and limit switches running properly, but accurate spindle control still eludes me.
I' believe I have everything wired in correctly, and I can send M3 Sxxxx commands, and get the spindle running pretty close to the commanded speed, however, I can only get the speed accurate with the potentiometer for one of the two spindle gears. I wired in an optical sensor to the spindle for an Index signal on Input C, so Mach4 is reporting the spindle speed accurately. I assumed that the PWM output of the 407 would adjust based on the Index signal but that doesn't seem to be the case. Am I stuck with a spindle only calibrated for one gear? Or am I missing something or perhaps going about this the wrong way?
I'm attaching some pictures of what seems relevant. If anyone can offer any help or insight, I'd really appreciate it. I really like the SmartBOB hardware and software, and this is the only thing that I can't figure out.
If it's any help, the VFD is a Delta VFD015E21A.
Thanks!
Malcolm