MMU3 and MK3S impossible continuous printing
Hey all,
I have been printing prusa since 2022 januari and started off with the MMU2S on a MK3S+. First months were testing my patience but after that, I had a few good months with zero issues. After the "power" issues came for the MMU2S I kinda gave up on MMU until the MMU3. I've modded quite some small changes since the start, like the chimney on the extruder, 3mm tube inside diameter, the RMU buffer, auto rewind spools (many iterations and known models tested), the E3D Revo hotend from 0.15 to 0.8 and many more small mods I am probably forgetting.
I've had the MMU3 since december 2023. To start over with the MMU printing. But the last test I've done, it took me about 40 manual fixes of the 100-ish tool changes. I've printed the forest tile 4 times of this model: Catan - base game 3D (high resolution MMU) - V2 by Thejiral | Download free STL model | Printables.com. I opened the file as a project in prusaslicer, so a lot of settings were already adapted.
I limited the colors to 3 to reduce the number of changes. For the profiles, I use most of the default Prusa slicer profiles now that they included 0.25 MMU profiles. The profiles still state MMU2S (Original Prusa i3 MK3S & MK3S+ MMU2S 0.25 nozzle).
I have most issues with loading and unloading. Although with unloading, the issue is a mystery to me, since the tips look very much OK. The unloading fails about 3 times on 100 changes. The loading, however, fails about 40% of the time. The other 60% of the time it cuts the tip after 3 failures and starts printing anyway. I have done the usual maintenance, oiled the rods, brushed and blow out any residue. Did a cold pull and the default calibrations (Z-axis etc)
The strange thing of the failure is, it fails to load exactly the same every time. About 4cm away from the nozzle. The print now took more than 80 hours while it was estimated at 36 hours.
These are some photos and a video on how its been printing ...
https://photos.app.goo.gl/9vLJeDyynPeMgbcp6
Any help would be appreciated!