Layer shift on a large print (i3 mk2)
Hey folks!
First and foremost - great printer! I assembled everything and got really good results early on which was phenomenal.
I do however have a bit of a puzzle to try and understand with a specific complex print I was testing, which has now resulted twice in very obvious layer shifting.
Some details:
Print: http://www.thingiverse.com/thing:1389413
Timelapse:
GCode file: https://www.dropbox.com/s/lzkrkne7unvtl69/Track_BB8mm.gcode.txt?dl=0
This is a testing object I printed to ensure things were working decently well, which they are:
My first attempt at the above object and for which I didn't take a time-lapse gave me this very obvious layer shift:
And my second attempt somehow met the same fate, though not at the same moment:
Since they appear to occur on the X-axis as far as I can tell (the time-lapse likely somewhat shows the part's orientation), I checked my belt and pulleys to make sure they were all screwed in/tight. No issue there and they are guitar string tight (almost). Gripping the X axis gear-pulley (the toothed thing...) with pliers and and attempting to move the stepper results in the stepper skipping, based on the noise so it doesn't seem related to that.
I'd welcome any investigative advice on what next I should be hunting for in terms of root cause for this issue 🙂
Thanks,
Mat
Re: Layer shift on a large print (i3 mk2)
Darn OSX keeps uploading phone-sourced pictures upside down... here they are again.
Re: Layer shift on a large print (i3 mk2)
Some investigative checks online are suggesting adjusting current/voltage on the steppers as that is reported to be a potential source of issues.
https://www.thingiverse.com/groups/prusa-i3/topic:4444
In addition to not knowing where to set that, I'm currently tempted to wait for some input from the folks here before I try and fidget around with that stuff...
Re: Layer shift on a large print (i3 mk2)
I'd welcome any investigative advice on what next I should be hunting for in terms of root cause for this issue 🙂
A shame you fixed your photos. I was going to make a comment about how printing upside often caused layer shifting... 😀
Some in the forum have had their PINDA bump into their prints. Apparently the PINDA Protector can help. Do you have one installed?
http://www.prusa3d.com/prusa-i3-printable-parts/#_ga=1.56997354.1794524405.1468079777
You might try a time-lapse with a shorter interval, or perhaps run a full video to see what happens.
John
Re: Layer shift on a large print (i3 mk2)
Mathieu
Are you printing in Quiet or High Power mode? Larger objects may require High Power.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Layer shift on a large print (i3 mk2)
I had hard times printing the same model. It has a lot of critical overhangs, where massive curling occurs regardless of how intense cooling fan goes. I had to increase Z-lift up to 1mm.
Re: Layer shift on a large print (i3 mk2)
Some investigative checks online are suggesting adjusting current/voltage on the steppers as that is reported to be a potential source of issues.
https://www.thingiverse.com/groups/prusa-i3/topic:4444
In addition to not knowing where to set that, I'm currently tempted to wait for some input from the folks here before I try and fidget around with that stuff...
I believe the current is set in the Firmware so tricky to change unless you can program. Though Josef did tease elsewhere that there is a firmware update coming that will use varying current to help with print stability so maybe that will help.
The only time I've had layer shifting is when I have changed the speed mid-print using the LCD... for some reason it always causes my printer to do a Layer Shift?!
I have heard that printing some objects at too higher a speed can cause it so maybe slow it down and give it another go?
The Simpify3D Quality guide mentions both the speed and electrical issues: https://www.simplify3d.com/support/print-quality-troubleshooting/#layer-shifting-or-misalignment
Re: Layer shift on a large print (i3 mk2)
Thanks for all the replies!
PINDA is unprotected, I can try installing one. It doesn't seem damaged at this point.
Can the PINDA technically sense PLA? If it can, it would make sense to use that logic in the code to get a feel for any creeping issues resulting in an eventual bump due to printed model z-height creeping up as layers are put down. Just a thought, Im not yet certain its logical 🙂
Power was set to the default, which was high.
Good point on increasing z-lift - I can try that! I take it that what could happen here is the axis getting stuck pushing against the model and the steppers would just skip and then eventually resume one layer up afterwards?
I never changed the speed mid-print. Not sure if Josef's firmware is at fault here anyway - the model does feel rather advanced for your average kit printer to handle 🙂
Thus I will try z-lift at this point, unless someone else chimes in...
Re: Layer shift on a large print (i3 mk2)
Z-lift is definitely your friend on this print. It happened to me on my MK2 as well as my home-built machine.
Re: Layer shift on a large print (i3 mk2)
The marble run. Been contemplating printing one of those.
Re: Layer shift on a large print (i3 mk2)
The PINDA only detect the 9 points layered in the heatbed, extruded material have no effect on it.
There are other possibilities that may generate this issue: Does the cables from the extruder or the heatbed get in contact with something while printing ? repositionning these cables will be necessary if that's the case.
When the Y axis belt is removed, does the heatbed move from front to back position without any effort ? It's not difficult to check that, you just have to unscrew the rear endstop, to remove one of the screw holding the stepper and loose the second one, so that the stepper can turn around this last screw (it's also an easy way to tighten the belt, so easy that at first attempt it will be way to tightened)
I'm like Jon Snow, I know nothing.
Re: Layer shift on a large print (i3 mk2)
hey guys,
I do have the exact same problem, I thought it may be caused by insufficent belt tension.
this was the first time I tried Simplify3d and was shocked:
I thought it may be caused by Simplify 3d and I stopped the print, then I tried again with Slic3r and let it run over night.
The results were better for the first layers but it also failend in the end:
This was the first time I made use of the large build volume, before I did not have such problems.
It was printed in silent mode, does this has such a great influence on the quality and accuracy of the print?
Any help appreciated, thank you 🙂
Re: Layer shift on a large print (i3 mk2)
Looks more like loose belt pulley.
Re: Layer shift on a large print (i3 mk2)
Hey, thanks for your answer,
I am prety sure that the screws in the belt pulley on the motor are tightend.
I will look it up when i come home but as I said I am pretty sure about it.
Could it be something else?
Re: Layer shift on a large print (i3 mk2)
Silent mode (weak stepper) in conjunction with improper acceleration settings of slicing software.
How did you slice the model? What software, what settings?
Re: Layer shift on a large print (i3 mk2)
Hey,
I've used the official settings for slic3r by josef prusa.
Re: Layer shift on a large print (i3 mk2)
One last idea and after that I'm out of ideas.
What is your relative Z distance between nozzle and probe? If the probe is too low, it might hit the object while printing. The probe should be 1-2mm higher than the tip of the nozzle.
Remember, if you adjust probe height, you should reset Z adjustment to 0.000 and redo calibration.
Re: Layer shift on a large print (i3 mk2)
hey,
the probe is higher than the nozzle, and the belt pulley is tight, checked both things, it may be the belt tension but I don't know how much i have to tighten it up because it is already tight, definitely not too tight bot also not too loose.
EDIT:
Okay it seems that my X Axis motor is defective, it is not moving anymore, I've contacted the support
EDIT 2:
Oh my god, the problem I had was completely my fault, I've tightend the x-axis pulley right against the motor, therefore it could not move properly 😳
Re: Layer shift on a large print (i3 mk2)
Just curious if you attempted that print again. Its been a while I know. 🙂
That dang marble machine has been almost impossible for me. I started printing on a Wanaho i3 Plus (w/ Flexion HT extruder) and it failed 3 times with shifted layers each time. I just tried it on my MK2S and had the same damn shift.
Its odd, on the Wanhao i3 Plus I used Simplify3D and the MK2S I used Slic3r. Towards the end of the marble machine you can see where some of the PLA curls a bit and I can hear it catching the extruder from time to time. Obviously that leads me to believe I need to use Z lift, which in the last prints I didn't use.
Oh FYI I printed the marble machine on a CR-7 with a E3D hot end and it printed fine (scaled at 51% for airsoft pellets). I used Cura to slice it with no Z-lift. So bizarre.