Y Axis Binding and I could use your help

Y Axis is binding. I’ve read through every post with binding in the text and implemented their solutions.

Gantries are parallel, square and level in every corner.

(Minor Fault) Left Side Y Axis Gantry is clocked 1 degrees to the outside of the table.

(Major Fault) X Axis Gantry is .08 degrees twisted end to end.

One bearing on all parallel sides are touching.

Gantry will slide freely and easily on Y axis with no lash when leadscrews are disconnected.

Couplings do not appear to be slipping.

Lead nuts appear to be in serviceable condition.

Connections at control box verified.

Motors operated independently to very serviceability.

More I’m sure I forgot to mention.

Synopsis of fault: Normal operation for many months. Binding issue occurred. Implemented trouble shooting procedures. Bad Stepper Motor. Langmuir replaced within three days. (Amazing by the way!) Installed. Motor now functions. Gantry still binding. Tear down and rebuild to insure dimensional accuracy. Still binding. Remove all rails, weldments and gantries to check for dimensional accuracy. Correct to within 1/32 and/or 1 degree and reinstall. Still binding.

I’m coming up on 40 hours and I’m stumped yall. Thoughts? Video attached. Thanks!

https://youtu.be/PaaiPvtMOqY

watching your video the lead screw does not turn when it binds. Is the motor still turning? It sounded like it might be… That would make me suspect the couplings…

I concur with @ScottNH

Set up your video camera and film The coupler joint on each side and do the same thing.

Or mark it with a felt pen across a line between the coupler and the shaft and see if they’re still lined up after.

Agree… Looks to me like the coupler on the far end of the table in the video is the problem… The near one always looks to be wanting to move but the other side is holding it back…

Thank for the quick responses. The couplers are not spinning. Verified with markings.
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I think you’re right. It’s definitely the far side lagging. Good catch.

It’s hard for me to see the marks but there is two places that coupling can spin.

It can spin between the coupling and the motor.

And it can spin between the threaded shaft and the coupling.

With the langmuir electronics enclosure powered off can you move the y-axis forward and back by hand without it getting tight?

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Ran every test possible on the coupler. It’s locked on tight. When the gantry binds the motor hums but it does not turn. We ran through the bearing blocks and alignment again last night. The system couldn’t be more perfectly aligned with the current components. Through further trouble shooting we noticed that simply touching the weldment carriage or the lead screw during movement would cause a bind. Not sure if that’s normal. I’m at a loss. I just can’t figure what misaligned everything to cause such a catastrophic failure after months of successful cutting.

Did you try oiling the lead screws? That is the only thing that would fix my binding issue.

weak stepper motor?

I had a binding problem that stumped me in the same way. I tried everything I could think of. Finally, I super cleaned the rail and the bearing faces that run on the rail and it got a little bit better. I cleaned some more and it got more better. After an hour of cleaning it did not bind anymore. The rails are exposed and in the line of fire. With 2 bearings on each of the 4 sides, adjusted snug for no play for accuracy, the smallest bump on the rail could cause binding. Try cleaning and see if it helps.

We tore down the machine and rebuilt it again. Welded the frame square. Replaced some bearings. Anything that felt the least bit suspect was smotthed or replaced. No change. Same bind. Does not bind on single direction moves, binds when changing directions. Ill throw the latest video up.

Video after tenth rebuild. The far side motor seems to lag behind the near side motor. The far side motor has been replaced already.

I wonder if you could switch drivers and see if it followed the driver? I’m not sure you can do this but I would investigate whether you could just exchange the cables on Y1 and Y2 just reverse where they are plugged in. I don’t see how the machine would know of care. But if it follows the driver it would emilnate the table construction and one of the motors.

Tried the simple version of that. I swapped the y axis cables on the control box. No change.

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So to me, that would seem to indicate either the motor is bad or something in the mechanical part of the table. I know you said you replaced a motor but how about swapping them from side to side to see if it follows the motor? You’d probably have unmount the control box as the cable won’t be long enough. What else can it be? The frame is square the bearings are free. The leadscrew and nut are fine? Could the leadscrew be bent? Might be worth taking it off and checking on a flat surface. I’m just throwing ideas at you hoping something might land… I know you’ve tried most if not all of it.

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Back at it in the morning. Thanks for the replies! Ill run through that tomorrow.

May not be relevant. Mine did the same thing a couple of months ago. Langmuir sent me a new motor. Same thing happened. It turned out to be the motor mounting bracket was not perpendicular to the rail. I moved the Y axis all the way to the back and just loosened the mount screws. The bracket snaped back into place. Problem was gone.

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Replied to one of the vids. Seems like you’ve eliminated the most likely cause, so I do wonder about the actual mechanical act of accelerating and moving. Shake it around by hand and see what you feel seems like the next thing to eliminate.

Thanks for all the replies, I appreciate it! Turned out to be a bad solder joint on the Y Axis connection. My partner noticed a loose connection. Solder was broken and the wire was only being held by the shrink wrap. Put a bullet connector on to test it. Worked flawlessly. Going to contact Langmuir tomorrow! Thanks again everyone!

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