https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/ Prusa3D Forum Discussion Board en-US Tue, 16 Jun 2026 06:39:31 +0000 wpForo 60 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136509 Wed, 03 Apr 2019 21:15:51 +0000 I'll try cleaning the build plate with detergent and give it a whirl. I did originally have a problem with adhesion when I first assembled it last summer.

>jan: That's what I'm in the process of trying to do. If I run the z-offset to where it starts adhering, it's too close. Anything else mostly gets a ride around the print bed.

Still doesn't explain the oozing right after tool retraction.
But, for now I'll settle for getting my z calibrated.

Thanks All - I'll post back with findings.]]> Assembly and first prints troubleshooting robert.f20 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136509 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136125 Mon, 01 Apr 2019 16:56:40 +0000 Did you recalibrate your first layer? Sounds like Z is (a bit) too high?]]> Assembly and first prints troubleshooting jwveldhuis https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136125 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136083 Mon, 01 Apr 2019 11:04:15 +0000
I find that IPA can be a poor cleaner under certain circumstances...

IPA Works best for me, when it is sprayed directly onto the COLD Build plate and then wiped off with a clean paper towel.

I use a spray bottle like above

if the IPA is applied directly to the Paper towel, a lot of it simply soaks into the towel, having no effect on the build plate.

if the Build plate is hot, the IPA Evaporates and leaves the grease behind.

I also find that taking the build plate, to the kitchen sink, and washing with detergent and water (dish Soap) like 'Fairy liquid', in the UK, and 'Dawn', in the US, then drying with Clean paper towels, removes grease well...

Beware that Cloth towels are often treated with 'Conditioner' which will adversely affect the PEI Adhesion.]]> Assembly and first prints troubleshooting JoanTabb https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136083 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136036 Mon, 01 Apr 2019 00:11:54 +0000 I have an MK3 I built last summer. Worked great. I just built the MMU2s and it is functioning, and upgraded the hotend. Flashed the firmware.
I have problems with the first layer.

1. First layer won't stick.
2. when it sort of sticks, when it get to the last stage (printing the patch) it just peels up and collects under the nozzle (blobs up).
3. Once it finishes, and the hotend retracts, just before it retracts the filament, it blows a wad out the nozzle.

I've tried various brands of filament. Last one I tried was a Prusa filament.

I've tried increasing the bed temp and that seemed to have no or little effect.
I've cleaned the bed numerous times with IPA.

Any guidance would be appreciated.
Thanks.]]> Assembly and first prints troubleshooting robert.f20 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mk3s-mmu2s-first-layer-problems/#post-136036