Weird MK4 layer shift halfway through large prints…
Hi all
I just wanted to discuss a problem we have been having for a few months. When using the Mk4 for large prints there is often a large layer shift halfway through the print, which forums tell me may be due to a software glitch? This does not happen at all for smaller prints. Belt tension etc seems fine.
I have attached a couple of photos for an example. Have you had any similar issues yourself or know how to fix it? Thanks in advance for your help
RE:
I have seen those layer shifts on my MK4, but only when using the input shaper profiles. So far the shifts have never happened when I was using the profiles without input shaper. If you are using input shaper, try to turn it off (by using the profiles without input shaper I mean) and see if the problem persists. The speed advantage of the input shaper is useless if you have to print (at least) twice and the waste of filament is also annoying.
RE: Weird MK4 layer shift halfway through large prints…
I had a similar problem, which was caused by a PrusaSlicer issue (#12381, fixed in 2.7.3). The slicer was generating a toolpath outside the print area, causing one of the axis to crash, thus causing a layer shift from that point.
Maybe it's something like that in your case? You might be able to check that by loading the gcode into the gcode viewer, enabling toolpath display, and see if it goes out somewhere.
RE:
May I join the club?
I have got one MK4 (purchased as Kit) and that one runs flawless for month. Yesterday I did the upgrade of my MK3swhatever to full MK4 and this printer has severe layer shift every second print. Initially 3 times in X axis, last print in Y...
Belt tension was checked with the frequency check tool and feels similar. Only obvious difference is the new upgrade is in a much warmer place. Same print works sometimes and sometimes not. Attached foto shows some examples, currently I tried to print the pre-sliced MM3 upgrade parts, are they sliced with or without input shaping?
On the other machine I typically print sliced parts with IS enabled, no issue. Any Ideas what else to check?
RE: Weird MK4 layer shift halfway through large prints…
Hit again, very slight shift this time. yes again the second print - so either bad luck or indeed temperature?
RE: Weird MK4 layer shift halfway through large prints…
Printed with input shaper or without?
RE: Weird MK4 layer shift halfway through large prints…
I honestly don't know, this is a pre-sliced file from Prusa for the MMU3 upgrade (more fun incoming 😉 ) . Will try a own-sliced version tomorrow.
Nevertheless, my other MK4 has no (zero) issues printing the same reliably - in the ~6 month I have this one I never had any shift, and I typically slice with IS enabled.
RE: Weird MK4 layer shift halfway through large prints…
The fact that it works on one printer is no reason why it should work the same on another printer. I think that IS requires a lot more precise finetuning on every printer to work flawlessly, especially as collision detection does not work and the acceleration is so much higher. So every time the nozzle encounters a little filament blob on its path a layer shift could be the result. On my MK4 IS works most of the time, but sometimes it does not and the result is totally unpredictable during the print, i.e. never twice at the same spot of the print. So I have given up on IS and wasting filament for this. Without IS the printer works as reliably as my MK3S+. It might take a bit longer overall, but I can count on the results, which is more important for me than speed.
RE: Weird MK4 layer shift halfway through large prints…
Well, of course there is differences, but ZERO issues on one machine in many many prints and a ton on the other seems to indicate an additional issue to me - yet the question is what this is. Or do you suggest this feature is built on such a fine line that t is most of the time not working? For this I see not enough posts here, keep in mind happy users won't complain. I did see filament blobs on the working printer as well. The working one is located next to me on my desk, so sometimes this could be a bumpy environment ;-).
But, I agree on the wasted filament part. Kind of disappointing if this happens often, tough I have to say that wasted time is more the issue for me (that is why I am interested in getting a fast printer in the first place...)
RE: Weird MK4 layer shift halfway through large prints…
Quick update - spoke with my supplier who has been having same issues. He recommeded disabling input shaper (which I never had on) and using the 'Quality' print settings rather than 'Speed' etc. Also advised against making your own presets at this stage because when there is a slicer update, the changes are only applied to the stock presets and not the custom ones created by users.
So far no more issues but I'll be watching carefully...