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Weird issue with motors going backwards randomly
« on: February 20, 2017, 10:25:08 PM »
Hey guys,
Need a little help.

So super simple coding screws up. Say machine coords are (Z0.0 X1.0) in midi I type (G01 Z-0.5 X-0.02) Z moves correctly but X goes neg but randomly jump back POS. Doesn't seem to be constant. If I press enter again after Z=-0.5 and X=.145 it doesn't move. It thinks it's at X-0.2 for some reason.

Any thoughts?.

I'll try and post up a video tonight

Offline kolias

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Re: Weird issue with motors going backwards randomly
« Reply #1 on: February 21, 2017, 01:06:46 AM »
Are the motor settings correct on the motor tuning and setup screen?

Normally in the MIDI I type G0 to test my axes, I don’t know what G01 is for

BTW if Z-0.5 is in inches, thats pretty deep to go into one pass
Nicolas
Re: Weird issue with motors going backwards randomly
« Reply #2 on: February 21, 2017, 04:38:29 AM »
The move is for vertical lathing.  G01 is a cutting move, speed is set with F feedrate. G00 is a rapid move, moves at machines highest speed or rapid speed setting. The problem isn't any setting, this thing have been up and running for 3 years. Only things I've changed are backlash.

This is a twitch tho. It goes in the neg direction, then the point it wiggs out what ever distance is left to designated coordinates it twitch's and goes POS.. so say I'm at X1.0 going to X-0.5 if it wiggs at X0.1 it'll go to X0.7 (0.1- -0.5= 0.6 + 0.1 = 0.7) super weird. Been doing it randomly for weeks but just tonight I tried to take a video and it was working fine.

Would still like to know what's going on. I know it'll happen again.

Also if you have ur machine set up right 0.5in deep is obtainable on aluminium. That's with using the correct and sharp bits at the proper feed rate. You have to of made the column solid. That reallllllllly improves rigidity. Chatter is the only thing that keeps you from deep cuts.

Thanks
« Last Edit: February 21, 2017, 04:45:01 AM by nissan20det »
Re: Weird issue with motors going backwards randomly
« Reply #3 on: February 24, 2017, 11:13:48 AM »
did you check to make sure that backlash comp is NOT enabled?
Re: Weird issue with motors going backwards randomly
« Reply #4 on: March 08, 2017, 03:33:11 PM »
hey guys having this problem again. I knew it would come up again. I re-posted but heres the link, I posted a video.
http://www.machsupport.com/forum/index.php/topic,34408.new.html#new

I doubt its backlash since it happens only wile going one direction, Its not in ballscrews, or any mechanical parts i can see. it has to be some electrical glitch. Need this piece cut today any help would be great