[Résolu] Wipe tower problem PVA (Primaselect)  

RE: Wipe tower problem PVA (Primaselect)

I am seeing similar problems, twice now I believe the extruder has crashed into the wipe tower and caused layer shifting. 

I am using the i3 MK3S with the MMU2S and working with soluble interface supports, when the wipe tower is used I see bulging from one side of the wipe tower, maybe when the filament is reloaded during the initial tool change and the wipe tower bulges at the point, eventually the extruder bounces off of this bulge causing layer shifting. Any ideas?

Thanks.. 

RE: Wipe tower problem PVA (Primaselect)

p-voet: Can you please attach photo of your PETG/PVA wipe tower?

croft: Are you sure, that you are using MK3S MMU2S printer profile? The behavior you are describing can happen if MK3 MMU2 (without S) printer profile is used on MK3S printer.

RE: Wipe tower problem PVA (Primaselect)

I took a file from Thingiverse that pushed presets to Prusa Slicer when I dropped the STL on the platter. I think you might be right. I double checked that my initial setup selected the MK3S with the MMU2, but I see from reading the LCD display that the file readout states MK3MMU2. I will clear the pushed presets and try again.

RE: Wipe tower problem PVA (Primaselect)

Posted by: croft

I took a file from Thingiverse that pushed presets to Prusa Slicer when I dropped the STL on the platter. I think you might be right. I double checked that my initial setup selected the MK3S with the MMU2, but I see from reading the LCD display that the file readout states MK3MMU2. I will clear the pushed presets and try again.

STLs don't push presets, only 3MFs do.

RE: Wipe tower problem PVA (Primaselect)

I have similar problems with PET. The MMU is really disappointing me... I think it is only working probably with PLA.

RE: Wipe tower problem PVA (Primaselect)

Vote and comment on github to fix this issue: https://github.com/prusa3d/PrusaSlicer/issues/2818

RE: Wipe tower problem PVA (Primaselect)

Starting with PrusaSlicer 2.1.0-alpha1 release, wipe tower was improved. Maximum volumetric speed of an active filament is respected to limit the print speed on the wipe tower. It should help with the PVA bridging problem.

RE: Wipe tower problem PVA (Primaselect)

@beni-g

I've been having problems with PET as well. The wipe tower often blobs up causing the print to be ruined. Not sure what settings might help, if any.

RE: Wipe tower problem PVA (Primaselect)

Due to the temperature differences it was advised by Prusa not to use PVA in combination with PETG.

This was the Prusa answer:

Please do not use PVA with PETG as soluble support. You will have to choose something with similar temperatures.

My suggestion is to use HIPS and lemonen or any lemon acid to disolve it.

Since then I use PLA with PVA.

So for me this topic is solved.

RE: Wipe tower problem PVA (Primaselect)

I think my issue was that my nozzle (between nozzle and heat-block) was leaking I had to tight this one.

RE: Wipe tower problem PVA (Primaselect)

@beni-g

Yeah, I'm going to try some different prints to see if the problem continues. My problem has been with only one particular print that I've been doing over and over again for days to try to get it right. Forgot to include that info in my initial post since it's easy to get tunnel vision when struggling over many days, lol. Easy to forget it's the same print :).

Add to that the fact I also just started to print with the textured plate and had a heck of a learning curve making that work. Then at the same time I slapped on a Olson Ruby nozzle, which I subsequently took off and went back to the brass so I could troubleshoot without too many variables.

RE: Wipe tower problem PVA (Primaselect)

@beni-g

I was looking at the wipe tower and I think that the problem could be the bridge distance. I just reduced it in slicer from 10mm to 3mm and will see if it fixes the problem on my next print. Maybe I also need to optimize the bridge extrusion settings for PETG, but this might be a quick fix.