RE: Filament head too large after unload (MK3S + MMU2S)
Sorry I must've misunderstood something. You asked for confirmation if anyone else had seen it, but if there are more than one video, Prusa's peeps can use it. At least that's what I'm assuming.
Sorry for the confusion.
RE: Filament head too large after unload (MK3S + MMU2S)
Ah. OK - makes sense. I, too, would like to know if I am on my own with this one or if this is something more systemic. Was thinking it might be related to the issues in this thread since the symptoms are similar. Keeping my Prusa, though. It is by far the most reliable 3d printer I own and I have a few. MMU release may have been a bit premature but I'm glad they did because otherwise I wouldn't have anything and its *almost* there!
RE: Filament head too large after unload (MK3S + MMU2S)
My send-back is a repair trip. Something is apparently uber-wonky, so they'd rather do that rather than send shotgun loads of parts at me. Eliminates "dumb Casey" from the mix.
I had great reliability on the MK3, MMU2, but when the MMU2S, it got REALLY REALLY bad.
RE: Filament head too large after unload (MK3S + MMU2S)
Thanks for the suggestions in this thread! I was having 'swollen tip' issues which as others have noted can be very frustrating. Changing the two mentioned parameters-'Unloading speed at the start' to 120 and 'Number of Cooling Moves' to 4 was like night and day, I've now gone through many hours of printing and well over 100 filament changes without a single glitch. Nothing else was changed from a situation where more than half the loads were failing. No idea exactly what these changes do, but they have worked for me.
RE: Filament head too large after unload (MK3S + MMU2S)
This is my issue, too. Support have tried to be helpful, but went straight for "user error" and had me tearing my machine to bits... twice, then factory resetting and reflashing - none of this did anything. My tips were coming out nicely shaped but too wide at around 2.06 mm and failing to reload at the lowest temperature I could set that wasn't stringing (around 201-210 depending on material). I have almost zero problems at the MMU unit end, it's all about reloading retracted tips causing failures.
I have just now had several successful tool changes in a row. Fingers crossed. Here are the things I remember changing 🙂
Filament Settings: Temp at 210 for other layers. I believe the target to be as hot as you can without stringing (tune this).
Unloading speed at the start: 120 mm/s. I have seen a thread here say it's a placebo and the printer can't actually deliver this. I don't know what to say there, but if I revert it, my success rate dips massively.
Number of cooling moves: 4. Should I get stable results, I will try reducing this.
I tried changing ramming settings... this seemed to not help at all.
I tried going cooler, it seemed to make things worse (wider). I tried going hotter, I got stringing and failed in a different way.
I do feel your pain here, it seems overly sensitive and requires precise settings that must deviate based on potentially material, perhaps some level of precision assembly (aligning things by eye is going to have deviation), maybe ambient temperatures play a part too. I've just witnessed many successful changes in a row whilst typing this. Wish me luck!
Is there a way to set this universally, or do we need to edit the filament each time they update the presets?