Nozzle keeps catching on paper in XYZ calibration
I just got my pre-assembled MK3S. I followed the handbook by removing the foam, and it said some parts are secured with white zip ties, and I saw a white zip tie on the x axis, so I cut it off. Carrying on, I removed the test print, calibrated the Z axis, unloaded the filament, loaded the new filament, until I tried printing the Prusa logo. It kept detecting a crash, so I got down on my haunches to its level for no real reason when I saw the additional white zip ties underneath. I hadn't thought to inspect its undercarriage. After cutting those off and recalibrating Z, it now makes the Prusa logo base, but some extra filament hangs above the rest, and I think it catches on those, because it continues to sound like it's touching the printed base, then globs on the nozzle. Since this happened, I've checked the height of the probe, followed steps on why adhesion might not be working, like wiping the base with IPA 91%, and several other troubleshooting steps.
I've also tried XYZ calibration. The Z calibration runs fine. After removing the steel sheet, it runs through the 1st calibration point fine, but at the second calibration point, it's like it forgets its Z calibration. It catches on the paper, and when I go to settings to move the z axis up, the z axis says it's at +0.000 while the nozzle is still touching the bed (through the paper). I just saw like 2 minutes before the XYZ calibration that the +0.000 on the Z axis was not touching the base, since I was beforehand checking that the nozzle was approximately 0.2 mm above the metal sheet at +0.000 like I saw to do online. The desk it sits on is level. So, tl;dr, checked that +0.000 Z axis was above the metal sheet, then XYZ calibration seems to forget the Z calibration and touches the bed.
I'm a real beginner at the MK3S. My college had an Ultimaker, and I wanted to try printing at home, but I never had to do any maintenance on the college 3d printer, so I'm a bit lost. Any advice would be appreciated.
Best Answer by Antimix:
I had the same issue in the past, after I dismounted the extruder or the cooler or the nozzle.
Today I had to dismount and mount it again for a jam, so I was forced to performed again the XYZ calibration.
As you, during the 4 points test levelling, on the 2nd and 3rd points the nozzle touched and moved the paper. I turned immediately off the printer. The nozzle was still basically in touch with the paper.
So, as described in the manual, I unscrewed the PINDA screw a little, I got one of the original Prusa zip tie, and I put it carefully under the PINDA, so that the distance of the PINDA from the hot bed was exactly the thickness of the ZIP tie.
Then I fastener carefully again the PINDA screw, and removed the ZIP tie.
I turned on the printer and redo the XYZ calibration, and this time the 2nd and 3rd point did not hit the paper and the calibration successfully completed. 😊
I always keep one of the original PRUSA zip ties as referral for PINDA calibration on my tool box.
Regards
RE: Nozzle keeps catching on paper in XYZ calibration
In the manual, you have to adjust the z axis, left and wright, with your hands, so the both sides do not crash in the bed.
First left, move to the wright, adjust both sides manual, so they at the same level.
Adjust the pinda probe, see manual.
Then I wood do a factory reset,(search forum),
and start all over, and follow the manual.
RE: Nozzle keeps catching on paper in XYZ calibration
Ignore what Peter-c26 just said - that is misleading and incorrect actions.
Contact Prusa using the store CHAT - they will talk you through the procedure.
RE: Nozzle keeps catching on paper in XYZ calibration
Thank you both for replying! I'll contact the store chat, just to be safe. I don't want to risk damaging a thousand-dollar machine (further).
RE: Nozzle keeps catching on paper in XYZ calibration
I had the same issue in the past, after I dismounted the extruder or the cooler or the nozzle.
Today I had to dismount and mount it again for a jam, so I was forced to performed again the XYZ calibration.
As you, during the 4 points test levelling, on the 2nd and 3rd points the nozzle touched and moved the paper. I turned immediately off the printer. The nozzle was still basically in touch with the paper.
So, as described in the manual, I unscrewed the PINDA screw a little, I got one of the original Prusa zip tie, and I put it carefully under the PINDA, so that the distance of the PINDA from the hot bed was exactly the thickness of the ZIP tie.
Then I fastener carefully again the PINDA screw, and removed the ZIP tie.
I turned on the printer and redo the XYZ calibration, and this time the 2nd and 3rd point did not hit the paper and the calibration successfully completed. 😊
I always keep one of the original PRUSA zip ties as referral for PINDA calibration on my tool box.
Regards
RE: Nozzle keeps catching on paper in XYZ calibration
Thanks, antimix, you were right! I contacted Prusa chat, like tim-m30 suggested, and all I needed to do was move the PINDA screw about half a thread towards the bed. I'll have to keep a zip tie, though, just in case!
RE: Nozzle keeps catching on paper in XYZ calibration
guy.k2 ( bunnyscience) has a nice pinda setup guage on thingiverse
https://www.thingiverse.com/thing:3555647
RE: Nozzle keeps catching on paper in XYZ calibration
Thank you for the fix! I was catching on calibration point # 2.
Thanks to you all - lowered pinda sensor a little (about 2 threads on mount) and it now proceeds without rubbing.
Now - onto tweaking Z again.
Thank you
RE: Nozzle keeps catching on paper in XYZ calibration
I feel like a lot of these issues could be avoided if they'd just use a real measurement for setting the probe distance in the manual. Zip ties come in many sizes and when you just tore down your extruder to replace a part or clear a jam, you never know what size zip tie to use and can't exactly print a height gauge on a non calibrated printer nor find the one you printed a year ago. I swear whoever writes these manuals thinks we are a bunch of children that can't use real tools, can't wire 120v psu connection, and loves eating gummy bears.
RE: Nozzle keeps catching on paper in XYZ calibration
I feel like a lot of these issues could be avoided if they'd just use a real measurement for setting the probe distance in the manual.
I once saw another method on the prusa site.
An old credit card is used for calibration.