Small Y-Axis movement on X-Axis direction change

Printer is an enclosed V-Core 3.1 500 I have an issue where there is a slight movement on the Y axis whenever toolhead changes direction on the X axis. Here's a video: https://photos.app.goo.gl/8qVE11bfJn74yuMT9 - Y moves on the first X movement in a the opposite direction of the last - Y does NOT move on subsequent X movements in the same direction - I cannot see or feel any erroneous X axis movement when I move the Y axis in either direction - The entire gantry moves when this happens; it's not erroneous Y movement only on one side, it looks to be uniform. I've played with a variety of belt tensions, it never seemed to makes things better or worse. Gantry is not racked; both ends of the X axis hit the frame at the same time. It looks like the belt paths through the motor mounts (I'm using FMMM) are good. Belts are in good condition, no fraying. I will say that I believe this was not always happening. I noticed it yesterday after my Euclid started to fail to dock/undock reliably, but it was working reliably for a good while before that.
1 Reply
wise-white
wise-white11mo ago
Resolved the issue. It turned out to be one of the spring couplers used in this mod: https://www.printables.com/model/299097-motor-decouple-damper The grub screw connecting the stepper motor's D shaft to the coupler worked itself loose somehow. I'm a little surprised since I had all of these screwed down tight with blue loctite applied. I reapplied loctite and torqued the screw(s) down again. Hopefully it holds... Sort of wondering if the motors are getting hot enough to soften the loctite to the point where it's no longer doing its job.