I3 MK3S and MMU2 – somebody to help me out of the jungle please  

RE:

Posted by: @tankred

Although my printer was in prusa service and got a overall repair, the printer does not work.

I am using a Prusa I3 MK3S and MMU2

I ran Slicer updates and updated the firmware to 3.13.2  and flashed to mmu3 firmware.

This does not work. I can´t find my setup in the slicer configuration, I can´t find  mmu2 firmware. Does anybody know what versions I am supposed to look for?

The MM3 firmware might not work with an MMU2.

Do you have an MMU2 or an MMU2S? The two also have different firmwares. You should install the correct one.

Here are all Firmwares to download. There are are sections for both MMU2S and MMU2 if you scroll down (don't stop at MMU3), where you can find the firmwares.
https://help.prusa3d.com/downloads?_gl=1*1rwlap*_ga*MTUzNjIwMjM0Ni4xNjk3NzI1NTc1*_ga_3HK7B7RT5V*MTcwMjg5MTk4OC45NS4xLjE3MDI4OTIwNDEuNy4wLjA.

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

PS: On a second look. It might be that the firmware for MMU3 and MMU2S is actually identical, not sure. The one for the MMU2 however is definitely not. 

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

@thejiral Thank you very much for answering. So I need to correct my initial question, I have a MMU2S. So actually I have chosen the right firmware, I just configured my slicer wrong. But still I am stuck with the idler cannot home problem. I changed the sensitivity to several values, but this did not change the game. I guess I look around now with that issue.

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

I am not totally sure what your problem is exactly, but if you say that your idler can't home, is there a hardware issue? For example the idler being blocked or something like that? Or is nothing happening at all? Do the lights blink or light up in any way? If so, check in the manual what they mean.

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

@thejiral thank you very much again for taking the time. I have the issue which is mentioned here. https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/idler-cannot-home-deadlock/

Since the update I can, at least in 1 out of 3 times, change the sensitivity of the idler in the printers dialogue. So far I did not find a setting, that helped. I checked if the idler can move or if something is in the way of the filament, so far I did not find an obstacle. But as usual, I try to do the same things again and check again for that and try out the settings.

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

Have you tried loosening the screws holding the Idler cover in place on the MMU ?
If they are too tight, whey can prevent the Idler roller from rotating

regards Joan

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

@JoanTabb thanks for your advice. I tried that and I removed the idler and the motor completely to be sure, that there is nothing in the way.

Am I right if I assume that the idler cannot do a full rotation due to construction? The printed idler parts only allow a like a 315° rotation, right?

the part in the circle blocks a full rotation. Is that by design or do I have a problem with the printed parts.

RE: I3 MK3S and MMU2 – somebody to help me out of the jungle please

Yes the Idler body has limited rotation, the Positive Stop, enables the MMU to  Know where the Idler position is, relative to the MMU body.

this is why during initialisation, the Idler Roller drives in both directions until it comes to a stop and these stop points indicate the end points of travel, from which the MMU firmware can identify the five idler positions for filament selection 

On the MMU3, one of these endstops has  little silicone buffer to reduce noise

Regards Joan