X-Axis Not Traveling Correct Distance
I've been running this printer pretty much every day for the last month and a bit. Not a single problem or complaint. As of today, however, the x-axis no longer moves correctly. For example, I can tell the printer to perform a mesh leveling, expecting the axes will travel to move the PINDA over 9 magnets across the bed. What actually happens is that the x-axis will travel a random amount of distance--always the correct amount or less. If less, there's a nasty grinding noise (motor skip) and the printer thinks the axis has traveled the correct amount.
I've checked belt tension and it's fine (260 for X, 273 for Y). I've checked the set screws and they're fine. When the skipping/grinding happens, the motor shaft is "bouncing" but not rotating. I've rerun a full set of calibrations, but that didn't help. Self test either passes like nothing is wrong, or stops because I need to "check the length of the x-axis."
I'm new to the 3D printing scene, so this is not something I'm equipped to deal with. I could use some help. I suspect the motor is bad.
Best Answer by --:
Do a self test. If it passes (big if) look at the belt status numbers. If X is significantly lower than Y - power off, and try moving X left right. You'll probably feel snags about where the extruder is stalling.
A common issue with Mk3s is the extruder housing parts are a bit oversized and can crimp the bearings, and loosening the rear screws near the bearings can help reduce X friction.
Also - if your bearings aren't packed with greased, then try a few drops of light machine oil of the rods and work it into the bearings (X and Y).
RE: X-Axis Not Traveling Correct Distance
possibilities:
loose motor plug at controller
broken x motor wire
loose belts that are slipping
high friction on x axis causing motor to skip
RE: X-Axis Not Traveling Correct Distance
Do a self test. If it passes (big if) look at the belt status numbers. If X is significantly lower than Y - power off, and try moving X left right. You'll probably feel snags about where the extruder is stalling.
A common issue with Mk3s is the extruder housing parts are a bit oversized and can crimp the bearings, and loosening the rear screws near the bearings can help reduce X friction.
Also - if your bearings aren't packed with greased, then try a few drops of light machine oil of the rods and work it into the bearings (X and Y).
RE: X-Axis Not Traveling Correct Distance
Ah! Thanks to you both!
I had previously moved the extruder right and left by hand, and yes, it moved. This time I paid closer attention to the feel: it was significantly stiffer moving to the right than to the left. I added a few drops of 3-in-One oil to the rods, worked the extruder along, and POOF! Glides smoothly.
Re-ran the self test and got X 278, Y 276. Going to try a print now.
RE: X-Axis Not Traveling Correct Distance
Good to hear - let me know how it goes. But also take it as a "heads up" you should add some grease at the next "service interval"... lol.
By the way - those numbers aren't useful for belt tension - but are good for finding friction issues.
RE: X-Axis Not Traveling Correct Distance
Sounds good. I was at about 38 days when I ran into this problem, so I should be able to go a couple of weeks before hitting that big 5-0.
I've run two 4-hour prints since then. One went from corner to corner on the print bed and had a little lifting at the two ends, but I was also a solid week since the last acetone wipe. Other than that, no issues of note. Just kicked off a 12-hour job for the wife.
Thanks again for all your help!
RE: X-Axis Not Traveling Correct Distance
I run the bed temp up to 70c for full bed sized prints - it seems to help keep the corners down better than 60c. But wait for the part to build up a bit before raising the temp or you can get some elephant foot.
RE: X-Axis Not Traveling Correct Distance
So it's still printing just fine. It's been going almost non-stop since the above posts (wife wants a lot of stuff done). It's started making a bit of noise, so I've re-cleaned and re-oiled the x rods. Now I'm thinking I need to grease the bearings. I've found some guides on how to clean and repack the bearings, but I haven't yet found a guide on the best method to disassemble the x-axis to get the bearings out. Do you guys know of a good guide? Or am I just going to reverse assembly of the manual, which looks like disassembling the z-axis to get the x-axis out?
RE: X-Axis Not Traveling Correct Distance
Seriously back off a bit on the extruder screws (5 of them I think) that hold the x-axis bearings.
It is really easy to get those too tight and bind the bearings. That can cause stiffness and noise.
There is no easy way to get the bearings out... Grease the Z-axis bearings while you are in there.
RE: X-Axis Not Traveling Correct Distance
A good thought. I checked those screws--they were not tight at all. Still backed them off just a touch.