My multi-color/-material printers

[AutoWiz]

Hey Spegelius, Chris Riley just released another video for the MMU2S. Unfortunately it is with a Prusa machine so it is little help to me BUT, he shows a redesigned part for the MMU2S from Prusa and filament cut feature that we can enable. Take a look: https://www.youtube.com/watch?v=LpoCYmSb7wo&t=

[spegelius]

Hey Spegelius, Chris Riley just released another video for the MMU2S. Unfortunately it is with a Prusa machine so it is little help to me BUT, he shows a redesigned part for the MMU2S from Prusa and filament cut feature that we can enable. Take a look: https://www.youtube.com/watch?v=LpoCYmSb7wo&t=

Hey Spegelius, Chris Riley just released another video for the MMU2S. Unfortunately it is with a Prusa machine so it is little help to me BUT, he shows a redesigned part for the MMU2S from Prusa and filament cut feature that we can enable. Take a look: https://www.youtube.com/watch?v=LpoCYmSb7wo&t=

Great, I?l have a look. Yeah the cutter is apparently a new thing, had a small issue while assembling it got it sorted (the blade wasn't in correct position). Haven't tried it yet, though.

So I tried PrusaSlicer and sliced a custom keychain part I designed a while ago. For materials 2xPLA (white and light blue) + BVOH for soluble support interface. The slicing process was quite straightforward, there's a profile just for this kind of setup. So filaments 1 and 2 were PLA, 5 is dedicated for the soluble material in the profile, can be changed of course, but works for me.

Loaded the filaments and started the print. For the first hour, everything went fine and the print looked good. But then the white PLA didn't feed properly and the extruder started skipping just when the filament was almost at the nozzle and that's a failure right there because the printer doesn't recognize this. MK3S might, as it has Trinamic drivers and should be able to detect missed steps.
So for that one mishap I paused the print, did manual unload and load and resumed the print. It continued ok for a while until another jam and I wasn't babysitting the printer so fail it is.
I kinda guessed that the MMU2S isn't that different from other solutions when it comes to loading performance with different filaments, there's just so much variance between different brands and even colors so it's just a matter of time consuming tuning each filament.
In this case part of the problem is the extruder itself: it's a direct drive with the motor directly driving the Bondtech gear, so no reduction gearing so the torque is not very good. So either bump up the extruder amps or get a geared motor. Maybe something like this: https://www.thingiverse.com/thing:3626993 although I'm not too keen on replacing the stock extruder as it just so much extra work with firmware mods etc.


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Here's a video of the start of the print with the filament priming:
https://drive.google.com/file/d/1MOX...ew?usp=sharing