MK2.5S / MMU2S issues
Hello everyone,
I got two weeks ago my MMU2S upgrade and after sucessful assembly and firmware upgrade to 3.7 / 1.0.5 I was quite eager to make the first multi color prints.
Unluckily i was unable to make one single sucessful multi material print.
My first print (3D Benchy in 5 colors) started quite promising and managed to print about 10 mm height without problems. Then the load failed for the first time and the print got interrupted, after that the mmu failed basically every 2nd time to load sucessuffly. I then decided to abort and troubleshoot using the manual. I tried all the things proposed in the manual (idler screw tension, tip modification using different temperatures and increasing the number of cooling moves, aligning the pullies and so on) but none worked. I then saw on the issues page of github the issue "MMU2s Loads to nozzle but then retracts before it continues print #1689" which suggested trying to use firmware version 3.6.0
Then I downgraded to 3.6.0 and tried to print an easier model (2 colored sheep from the sample prints) whitch printed well for some layer but then the gears started grinding the filament and the print failed.
After that, it failed every time. I retried to print the sheep but it failed again and again at latest after some layers.
So with firmware version 3.7 i had basically every 2nd loading failing and with 3.6 i have the print aborting after a few layers.
Interestingly, the printer works fine when using the printer in single mode.
For me it seems to be a firmware issue with the "distance between the extruder pulley and the nozzle" that is assumed to be larger than it actually is. That would explain the behavior with the failing loads with 3.7 and the grinding of the gears in 3.6 because the fast load is done for a too long distance.
Does anyone of you observe similar issues with the MK2.5S / MMU2S?
Or has anyone a solution for my problems?
Thanks a lot
RE: MK2.5S / MMU2S issues
Hi flurin-f,
Your issue looks pretty similar to mine.
I posted the solution that worked for me here.
I used firmware 3.7.1-RC1, but 3.7.0 should do it as well.
Guillaume
RE: MK2.5S / MMU2S issues
Hi again,
I have replied too quickly, the problem came back...
RE: MK2.5S / MMU2S issues
Hi Guillaume
Thanks for your suggestions. I completely disassembled and reassembled the extruder this week and attempted to print twomulticolor prints this week. I also upgraded the firmware to 3.7.0
Both failed to load the filament multiple times (load errors, unload errors, finda getting stuck and grinding in the extruder and in the selector...) and I had to abort them after some time. The first print some filament got stuck in the selector and for the second print at some point the filament was not feeding anymore properly in the extruder.
At least in single mode I can use the printer for normal printing. I really don't know what i should attempt now... it seems to me that somehow the issue is firmware related or maybe related to the design of the parts. maybe i will attempt do redesign and reprint some stuff...
I really hope that somehow they manage to make the mmu more reliable, at the moment it is for me only a overpriced material selector...
Flurin