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When you say you can remove motors and retune to start point of gecko 320 instructions are you leaving everthing else intact IE Cables, Breakout Board
Servo Drives remain mounted etc...?
Jeff...
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I'm new to CNC conversion. I'm converting a Grizzly X3 bench mill
to CNC and am having trouble getting my servo drives tuned in so they
have enough torque. Peak torque is 1125 oz-in and constant torque is
235 oz-in. Power supply is 72vdc @ 20amps peak. Got bigger motors because I didn't want to be underpowered. Motors run fine when bench testing. I can install coupler and squeeze with my hand with motors running in both directions and torque is not an issue. Motors would twist my hand off if my grip were stronger. I've blown 2 power supplies and 1 gecko 320 and 1 encoder. Big thanks to kellinginc for replacement parts. I'm not an electrician by any means but I had replaced gecko 320 with new new encoder checked wiring and rechecked and check again. Servos were mounted on mill on X and Y everything ran smooth I had .0001 repeatability within 3 inch move and with longer G0 commands. I adjusted gibs to get slop out of table. Still everything worked grate. I copied a new machmill.xml file into mach3 for
C11G board and rerouted computer monitor cable, keyboard cable, and mouse cable. Now servos run rough. they will whine as if looking for a line on encoder wheel no torque now and motors will start and stop osillating and vibrating wildly moving on own. I've tried everything from swopping motors to different pin assignments in mach3.
Nothing works. I can't recrate what was working before. Old saying is true "If it ain't broke don't fix it." I can remove motors and retune to start point of gecko 320 instructions. Lots of torque both directions. Remount motors and poof nothing. Project is turning into a big money pit with lots of wasted time.
Any help would be appreciated.
When you say you can remove motors and retune to start point of gecko 320 instructions are you leaving everthing else intact IE Cables, Breakout Board
Servo Drives remain mounted etc...?
Jeff...
Drives stay in control box. Motors are back on bench set limit to 1/4 of full set gain to 0 of full and damp to 1/4 of full then increase as required to obtain good torque. Would running earth ground to frame help with noise? motor + and - are running side by side with encoder cable. Thinking about seperating them and move computer and all the rest to other side of shop and see if that helps. Had advice about noise making servos think they are getting command to move and should seperate encoder cable and motor leads.
Still think I'm getting interference thru frame of mill but don't know how to stop. Motors go back south when mounted to machine. Maybe need a resistor here or capacitor there. All this is still new to me. Been toolmaker for 30 years and used manual machines. CNC looked good for way to do some extra work on the side for after retirement day in a few years.
How long are the encoder cables and are they shielded?
How did two power supply's go bad?
encoders are standard length shielded plugin type i guess 6' ordered from kellinginc.net. connecting wires while power supply on to X axis gecko shorted main supply leads in and blew copper off supply circuit board. gecko was shorted across main dcv power leads found out the hard way when same thing happened when turned on new power supply. fireworks smoke lights dim. learned the hard way to use meter to check for short and most important never connect anything when power supply is on like i said i'm no electrician.
If it ain't broke don't fix itOriginally Posted by handsmfg
From what I understand in your original post:
Things were working fine, and then you rerouted (cleaned up) all your wires, and then you had erratic operation in your motors.
This sounds to me like if you bound up a bunch of wires, you may be getting interference from one set of wires into another set. Try moving the wires apart and re-test.
I later read that you might have a ground issue through your mill, but didnt quite understand that part.
Regards,
Eric
From you second post, it sounds like something is getting shorted to the mill, or its some sort of ground problem. Perhaps try a heavy frame ground wire from the motors to the mill, or even to the controller box too. Maybe one of the cables has a short in it? Did you try the mounting the motors one at a time?
Eric
The reroute was computer monitor wire keyboard wire and mouse wire. I put them on a cart so I could get closer to the mill. I think I got the motors to move ok one last time before I overwrote the mach3mill.xml file in mach3 and then everything went south. I'll try the grounding advice and see what happens. Thanks for post.
I'm an Eric too.
Thank you for all who posted. I seperated the encoder wire and motor leads.
I also ran a heavy gage wire from frame to my earth ground. Motors were still running eratic. On the C11G you could see the output lights wigging on and off losing siginal i guess. I set frequency of C11G to 60000. That seemed to stablize things less eractic movement. Rebooted computer and started Mach3
did a coulpe of jogs on X and Y. Everything worked ok tried to turn on spindle but wouldn't work. Remembered that analog signal to speed board only works at 25000. Reset back to 25000. Servos run smooth and won't bind or stop. Massive torque now. Got late and didn't have time to tune X and Y in with indicator. I have a 2 axis CNC VMC now. Now comes the cool patrt of being able to CNC my Z axis motor mount. Again much thanks for all who posted and for the expert advice.
Eric.
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