Got it running, but I have noisy steppers on XY&Z

[mjindustry]

Hello people. I recently purchased a used PRT. Got it set up and it is running, but the steppers make grinding and chattery type movements. It seems like it happens in the same rail locations. For instance it will run smooth for a few inches...then chatter...then smooth again. so on and so on. It will pretty much do this all of the time. It doesn't sound very pretty at all. It happens on the X and Y...even a little bit on the Z.

Here is a google video of exactly what it does...
http://video.google.com/videoplay?docid=-5203539522706250134&hl=en

It's a 2006 model PRT Standard 48*96. Version 3.5.4 control

[Buckeye Don]

Jason it sounds like the stepper motors are losing steps. How many inches per sec. are you trying to move it? Another thing to check is to make sure the motors are not pulled too tight against the rails. On my older PRT I didn't have a smooth cut and had problems with losing steps until I loosened up the springs holding the motors. After the springs are taught only tighten another 2 or 3 turns. Hope this helps.
Don

[myxpykalix]

It sounds and looks like you have something binding. Have you inspected the rails and pinions for wear? I wouldn't run it till i get the problem resolved. It sounds like you are tearing something up the more you run it.

Take all your motors loose and inspect the pinion gears then give it a move command. If it makes the same noise then that tells you it is a gear inside the stepper motor.

If it does not make that noise then remount your motors and move it again while watching each motor and take a marker and mark on your pinion rail where it makes the noise and inspect the rail at that point.

[myxpykalix]

after rewatching your video it looks like the gears on both the X and Y and making the same noise. The chance that all your motors are bad is slimmer than maybe an installation error.

Did you see this unit working before you bought it? I have only put one unit together so i don't have that much experience but i don't think there is a difference in gearing between motors, there no left or right side, front or back.

[mjindustry]

Thanks for the help guys. Don I loosened up the springs to the steppers, gave them about three turns and now it all runs smooth!


I had them all cranked down to the max, not good apparently.

[Buckeye Don]

Great, glad to hear you've got it going.