Taz Workhorse Z Axis

When the Workhorse homes, it mashes the gantry to the top of the frame. So presumably it’s level at that point. After a print, every print, the left side is lower when it rehomes again for the next print. This causes the right side to hit first and then a terrible SNAP/BANG/POP coming from either the Igus bearing mounts or something in the vicinity of the idler assembly. Something during a print causes the gantry to get out of level. What’s weird is that I can home, and then repeatedly move the gantry all the way down and all the way back up multiple times and it maintains being level. It’s only when it starts to print that it gets out of level.

I think the probing is causing it. Looking at my mesh, the bed is like 2 entire mm higher on the left side. It’s like the pressing down on the pad causes it to lose steps.

Could this be the stepper motor or the gears in the stepper motor? Any suggestions on how to resolve this? The noise it makes when it rehomes is so loud it leads you to believe something snapped in two. Imagine a pencil being snapped in two, that’s what it sounds like.

If you can catch that on video and share it, that would be very interesting.

What’s the end gcode of your prints?

If there’s gunk on the nozzle that requires extra pressure to “push” through to get a connection on the washer, you’re going to get some slipping on the belt or missed steps. That puts your gantry out of level. When it hits the top to home the Z, both switches need to be hit simultaneously for it to stop. If one side hits first, the Z keeps raising until the second is hit. In theory, this means that it self-corrects and gets a mechanical level. But in practice, it sometimes “bounces” off one switch, then only the other switch hits, and it keeps raising, and bouncing back and forth until it hits the software limit for raising the Z, or both switches manage to hit at the same time.

The solution is to manually move the gantry up near the top. Hold it in place with one hand, then disable the motors from the motion menu. Now, pull the gantry up the the top with both hands, against the switches. Hold it in place with one hand now, and re-engage the motors by lowering the Z 1mm. Don’t fight the movement with your hand as it moves down.

Now it should home fine.

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I would unpin cura , reinstall pin it , turn it on reset firmware , then reset your computer then try if not call customer support

Yeah if your trying to get off pla or flush it try 240’s•C but not too long

I have this same issue on my Workhorse. I’ve tried to tighten both Z belts but that didn’t help. I will give this a try @Wrathernaut.

Some more details, nozzle is closer to the bed on the left side of the printer. Had some homing failures “please reset printer.” Also I have heard that breaking the pencil sound.

I did fix this eventually, permanently, but I had to replace both z stepper motors and both z motor pulleys. The belts were completely fine, as I examined each tooth on each belt meticulously. I also tightened down the bolts clamping the igus bearings into the z axis assemblies. There was a grinding sound coming from one of the z stepper gear boxes.

Now, after a print job, when it goes back to home to top of frame it hits each side simulaneously. Or amost so. Previoiusly, after a print job one side was way out of sync from the other.