So here's how I f**ked up my beed
I changed my Nozzle for a 0.8mm that is bigger and longer than the usual 0.4mm.
I wasn't aware that it would require changing the height of the pinda.
In the first layer cal settings, we can't set a positive offset, therefore I thought I would be safe at the max (0mm). I now understand why it doesn't make sense to have a positive offset ; because the pinda would be touching the bed at 0mm.
However despite watching a lot of videos on Prusa printer I would have never guessed this would have messed my bed. I had a tiny doubt as I noticed the hot end was longer but I didn't thought I could do anything more so I let the printer go and prayed. Guess what ; god doesn't exist, it ended up in the bed.
In order to prevent this from hapenning to other users, since my fiirst thought was to set a positive offset, I would suggest to let user dial in positive z axis offset, and not validate it, but istead display a warning :
"Warning : Pinda should be ~1mm lower than the nozzle or nozzle will hit the bed. If a positive offset is desired, move the pinda instead."
Picture included for the PLA tears.
Best Answer by Crawlerin:
@dessimondboris
Yeah they mention that MINDA is set from factory and no need to adjust it and don't put emphasis enough that you need to adjust it every time you manipulate with nozzle or hotend. Their online documentation states it in every article though.
RE: So here's how I f**ked up my beed
Hum actually, according to this dude pinda should be 1mm above the tip of the nozzle.
Let's now try to see if the nozzle land again in the same spot. 🤪
RE: So here's how I f**ked up my beed
0 is the distance that MINDA triggers when it detects metal surface (it's an induction probe), 2 mm is its sensitivity range. When it detects metal, it triggers and for printer that's 0. Positive value would mean you are lifting it above range it can detect surface. Live Z means you are lowering it below the value it triggered. Normally you put nozzle slightly touching the bed, and put a ziptie or a credit card under MINDA. Here's how to do it, this is for Prusa i3 MK3S but MINDA adjustment is the same: https://help.prusa3d.com/en/guide/9-preflight-check_76792 steps 1,2 and 3. This way it will also help you verify whether your X axis is parallel to the bed, if not, you may have to release 3 screws and adjusting it properly instead of moving Z motors.
RE: So here's how I f**ked up my beed
Thanks, I managed to solved this and to print successfully at 0.8mm with the mini.
I understand now that adjusting the pinda/minda makes totally sense, but I wasn't understanding it fully before messing it up :).
It may not be clear to new 3D printer users. My point is only that maybe you should document it better : I expect some other new users to do the same mistake.
Thanks most nozzles are the same size.
I'm quite happy that only the bed was damaged, and that the mini was able to endure the torque without breaking anything despite my mistake.
RE: So here's how I f**ked up my beed
@dessimondboris
Yeah they mention that MINDA is set from factory and no need to adjust it and don't put emphasis enough that you need to adjust it every time you manipulate with nozzle or hotend. Their online documentation states it in every article though.
RE: So here's how I f**ked up my beed
I now have leakage, I removed the head and, it seems that I ruined the thread of the heater block.
RE: So here's how I f**ked up my beed
@dessimondboris
Its better to contact support and order and new heatbreak and heatblock. Even better you can get the upgraded heatbreak from Bondtech.
Original Prusa Mini + Smooth PEI
Prusa Slicer 2.6.0
RE: So here's how I f**ked up my beed
It turns out that the wobble was mostly because the 0.8mm head wasn't screwed all in.
The chinese nozzles I got is bigger but I noticed the thread was shorter to compensate for that.
While other nozzles should be ~2 off the heatblock, this one is designed to be flush.
Since I disassembled it & cleaned it entirely with a scalpel, I damaged the thread even more and it doesn't seal perfectly for sure now :).
Therefore I will still try the v6 heatblock and repport results.
I havc prusament of all types to test.
RE: So here's how I f**ked up my beed
The standard V6 is slightly bigger than the Mini heatblock so I don't think it will fit. It is worth the try though.
Original Prusa Mini + Smooth PEI
Prusa Slicer 2.6.0