MK4 X-axis Self Test/Homing failing
Hi all,
I recently assembled a MK4 kit and am currently stumped trying to solve a problem with the X-axis not homing correctly/failing the self-test.
To summarize the issue: The X-axis appears to "two-step" and just run +X a certain distance, -X a lesser distance, before eventually hitting the right stop and banging against it repeatedly until it errors out and restarts.
I have tried various proposed solutions across both the forum and the subreddit to no avail (list below).
- Tightened the belt
- Also checked the pulley orientation.
- Tightened down the right cable cover on the nextruder, before eventually removing it entirely.
- Removed the Loveboard cover.
- Reorientated the cable sleeve zip ties in the back (they were blocking some movement)
- Tightened down the fan door screw
- Loosened both bearings
- Relubricated rails and bearings.
- Factory reset and reflashed multiple different firmware versions.
What I have not done was investigate the xBuddy more thoroughly than inspecting the cables.
Nothing so far has seemed to correct the error, and I've run out of ideas.
I've attached a video of the error here:
Anything and everything helps.
RE: MK4 X-axis Self Test/Homing failing
The error is on the side of the X-axis motor! Both branches of the belt in the direction from the carriage to the motor mount on the left should be parallel, just as you have them in the direction of the tension pulley on the right. But you have them as converging to the side with the X motor. Instead of a video, put detailed photos of the motor storage and the belt guide at the motor and on the X carriage. Check if there are any obstacles in the cavity of the left bracket where the belt goes.
RE: MK4 X-axis Self Test/Homing failing
I went and adjusted the issue, there was a little bit of debris in the belt channel. However, that only solved the problem for a short while before the error returned. A user on reddit pointed to a possible firmware issue with 5.1.2, and so I reflashed an older version (4.7.2.) and that seemed to fix the issue for now. I'll be getting on the line with support if it decides to reappear.
Thanks for your help,
NSD
RE: MK4 X-axis Self Test/Homing failing
If you get the error back, you have the entire X-axis assembled incorrectly. And you can't do it with any FW downgrade. Check everything on the X-axis, preferably by taking it apart and reassembling it with constant gradual checks, taking into account all the notes in the manual (seating of the rods in the printed parts, cleaning possible dirt in the holes, also check the operation of the belt in the cavities of the printed parts to see if it is rubbing somewhere sides of holes, etc.) Furthermore, it is also necessary to check the correct seating of the connectors on the electronics board. My printer, also assembled from a kit, had no such problems.
RE: MK4 X-axis Self Test/Homing failing
I have a factory assembled MK4 and have checked all the things mentioned- if it fails I can power down and up and it will resume the print after homing/leveling. I love the printer and am about to order an upgrade kit for my first i3 but would really like to see a resolution to this problem. It worked fine until firmware upgrade as I recall- and no I cannot name the firmware when it started failing occasionally. Thanks Gene
RE: MK4 X-axis Self Test/Homing failing
I had a similar problem that turned out to be different then the problem NSDoppler was having, but while I was having the issue I found this thread thinking my problem was the same so I wanted to post the answer here. Sometimes when I would start prints, the purge line and print would start ~20 mm over to the right, and sometimes the print would be in the right place. It turned out to be my filament holder hitting the extruder head. When I started a print when the extruder head was at the highest point in the Z-Axis it would calibrate the X-axis first, and run into the filament holder. This was more of an issue because often I would restart the machine at the top level after doing maintenance and then the Z-axis controls wouldn't let me move the Z down until the machine had been auto-homed. The fix was just to stop resetting or turning off the machine at the top of the Z-axis, and to not start prints when the extruder was all the way up.
RE: MK4 X-axis Self Test/Homing failing
I've had the same problem since receiving my assembled MK4. I upgrade to MK4S hoping that would solve the issue, but it has not.
The first time I print for the day, the X-Axis homing fails. It might fail for 30 seconds or a minute, but usually always is successful, then does a Y-Axis home which always is successful, then prints.
Sometimes on the 2nd print, if I do not print right away, maybe in 10 minutes, X-Axis home will fail again.
On the 3rd and subsequent prints, if I print within a few minutes, the homing never fails.
So, X-Axis homing fails when the printer is cold.
RE: MK4 X-axis Self Test/Homing failing
Im having a similar issue: Sometimes the x-axis homing seems to fail but succeeds, sometimes it says a collision was detected.
I can tell my belt isnt running parallel, but there is no debris anywhere.
When the homing fails, the x-axis seems to step from left to right but only 1/3rd of the way anf than hits the left side again.
Anyone found a solution?
RE: MK4 X-axis Self Test/Homing failing
I started getting this problem on my MK4 upgraded to MK4S, but noticed it was only after I did a tall print. I had already checked all the things mentioned earlier without success, and it was only happening when the print head was left at a high Z position when I started the homing.
Manually spinning the Z axis to a lower position fixed the problem pretty consistently. I suspect a firmware tweak is needed to resolve this. For now my workaround is to manually position the Z axis to less than 100 mm after a tall build before powering down.
RE: MK4 X-axis Self Test/Homing failing
@pkoopman: What you say makes me think: check whether the printer is standing on a stable basis. Mine is on an unpainted 'Ivar' shelf in the attic, (unheated space) so it may bend and skew with changes in humidity. I have the impression the printer has more problems (=needs more tries) calibrating after a change of weather. Also, dust or debris under the base pads may cause the printer to be 'wobbly'.
Last but not least check tightness of screws. All should be firm but the screws holding the z motors should not be firmly tightened, just lightly, or they may bend the Z-axis screws.
RE:
After installing firmware 6.2.2 the issue of multiple head banging (mine and the printer's) seems to be resolved. On a first print the head homes against the left rail a couple of times, then the bed homes and all done. I've not had a failing since. And... I've not changed anything on the printer, nothing tightened, nothing moved, same support... nothing else has changed except the firmware.
RE: MK4 X-axis Self Test/Homing failing
David -- Thanks for the hint about firmware updates. I'm at 6.1.4 so I will update.
efvee -- Appreciate the suggestions. I am on squash ball shock mounts on a concrete paver to reduce harmonic vibrations. Screws are tight. No weather change. I'll see if the update helps and revisit z axis screw torque if that does not resolve it.
Thanks for the feedback from both!
RE: MK4 X-axis Self Test/Homing failing
Follow-up: after reflash I moved to maximum Z axis value and auto-home worked perfectly on two out of two tries -- with a lot less thrashing around than auto-home on the older firmware version. So I recommend others with a similar problem try the firmware update as a first step. Again, I appreciate the help!
RE: MK4 X-axis Self Test/Homing failing
My issues were solved by the update as well. thanks Gene
RE: MK4 X-axis Self Test/Homing failing
Nothing in the notes about it, but very glad it seems to have been resolved.