Y-axis off, cleaning hits pad holder


I have tired asking support, but not really gotten an answer that fixes my issue.

I had the front y axis switch wire go bad/break. Initially I thought it was the switch so I pulled the whole print platform off and tried swapping to a new switch, before just running a new wire and using the old one. Got it all re-assembled and triggering, but running into a new issue.

During the leveling and cleaning cycle the platform doesn’t quite line up with the print head anymore. This is causing the print head to hit between the cleaning pad and the back plastic holder. It also is not hitting the front two pads when it tries to level. I have cleaned everything and tightened everything I can think of but it doesn’t help. I have also tried shimming the front stop as a suggestion from support. I did a clean install of Cura and flashed to the newest firmware included with it.

Any ideas would be greatly appreciated!

I have the same problem, and am about to try a likely solution; I’m waiting for nuts and screws to arrive from McMaster-Carr. A video showing my printer having this problem is at https://www.youtube.com/watch?v=FLG6oYMs6xk

I found a note in another part of the forum, that talks about this problem: https://forum.lulzbot.com/t/y-axis-0-endstop-question/4486/1 The first reply by ScottW basically says that if you have a 1.0.3 Mini running the latest firmware, you’ll see this problem. The solution he recommends (which worked for several people on the forum) is to print a new (1.0.4) Y axis motor mount and replace your existing one. He explains the 1.0.4 part is a few mm shorter than the 1.0.3 part, which throws off the wiping and auto-leveling positions.

See https://download.lulzbot.com/Mini/ to find both the printable 1.0.4 Y axis motor mount (https://download.lulzbot.com/Mini/1.04/production_parts/printed_parts/y-motor-mount/), and the BOM (“Bill Of Materials” - the full list of nuts, screws, etc.) https://download.lulzbot.com/Mini/1.04/production_docs/, Mini-Subassembly-BOM.ods. Also useful is the instructions for assembling a new, 1.0.4 mini: https://ohai.lulzbot.com/project/mini-104-bed-plate-assembly/mini-v104/. By the way, the “Nut Press jig” they talk about is now a printable part, “nut_insert_tool.stl” under the Jigs directory: https://download.lulzbot.com/Mini/1.04/production_parts/jigs/. I also found Aleph Objects’ nice page on how to do heat-inserts: https://www.lulzbot.com/learn/tutorials/heat-set-inserts-tips-and-tricks

Good luck,

Update: My Lulzbot Mini now successfully wipes the nozzle in the right place!

Yes, replacing the 1.0.3 Y axis motor mount plastic part with the 1.0.4 part and (importantly) installing that part according to the 1.0.4 instructions, fixed the problem for me! See my lengthy note on why, at https://forum.lulzbot.com/t/y-axis-0-endstop-question/4486/8

One more tip about replacing that part: I posted a video of how to insert the heat-set inserts: https://youtu.be/yZXz131e7fs (the sound is pretty bad, so you might want to turn on the Captions).

I see I left off some important details about replacing the 1.0.3 Y motor mount:

Follow the 1.0.4 instructions about setting the horizontal screws in the mount so their heads are just flush with the face of the part. If you tighten them much beyond that, the nozzle won’t wipe in the correct place. The nozzle wiping is a Y scale error test.

I bought a 3 mm heat-set insert installation tip for my Hakko soldering station: https://www.amazon.com/gp/product/B078K72615, and set my soldering iron to 240 degree C (the low end of the PETG extrusion temperature). It worked great.

The Lulzbot model for the nut insert tool turns out to be too short. I edited Lulzbot’s FreeCAD file to make that tool 30 mm long.

Don’t use a heat gun to remove the threads from the nut insert tool. That tool melts way too easily. Leaving the threads alone didn’t cause me any problems.

The plastic nut insert tool is good for only 2 or 3 insertions, which was enough for my replacement. Installing the nuts and screws was a bit of a pain, because the nut needs to seat properly in a deep hole.

Before I installed the heat-set inserts on the real part, I printed a practice block with 8 holes of the same dimensions as the real ones in the Y motor mount: 2.3 mm radius (4.6 mm diameter), 8 mm deep, 1 mm chamfer of the outside face. Since the heat-set inserts from McMaster-Carr come in boxes of 100, I had plenty to practice with before moving on to the real part.

Installing the heat-set inserts was easy.