MMU runs filament backward when loading?
When I try to load to nozzle, the MMU pushes the filament to the extruder, the IR sensor triggers, and then the extruder runs backwards... The MMU then pulls the filament out (all the way back) and the extruder is running forward (as if it's hoping to get filament).
It seems like the extruder and MMU are doing the opposite of what they are supposed to when loading to extruder. Can anyone help out?
I've checked all sensors working correct and consistently, anything else I should check?
RE: MMU runs filament backward when loading?
I too have the same Problem, Can a Mods get some Tech here for supportS?
RE: MMU runs filament backward when loading?
When I try to load to nozzle, the MMU pushes the filament to the extruder, the IR sensor triggers, and then the extruder runs backwards... The MMU then pulls the filament out (all the way back) and the extruder is running forward (as if it's hoping to get filament).
It seems like the extruder and MMU are doing the opposite of what they are supposed to when loading to extruder. Can anyone help out?
I've checked all sensors working correct and consistently, anything else I should check?
Try to take make it darker, turn off the light.
RE: MMU runs filament backward when loading?
When I try to load to nozzle, the MMU pushes the filament to the extruder, the IR sensor triggers, and then the extruder runs backwards... The MMU then pulls the filament out (all the way back) and the extruder is running forward (as if it's hoping to get filament).
It seems like the extruder and MMU are doing the opposite of what they are supposed to when loading to extruder. Can anyone help out?
I've checked all sensors working correct and consistently, anything else I should check?
Try to take make it darker, turn off the light.
No Joy. Lights off in a dark room. Still fails
RE: MMU runs filament backward when loading?
In another thread the solution was a clogged hot end. I am able to push the needle down with an Allen wrench from the top, so there is a path. The sequence gets out of whack in between attempts. I have had this running pretty well for 2 months. IR and FINDA are correctly adjusted and indicating correctly. Just filament loads, extruder takes it in a few turns, then backs it out (Still shows 1in IR) then the MMU sucks it all back up and repeats (IR 1 goes away when it retracts).
RE: MMU runs filament backward when loading?
Most errors of this kind are due to misaligned sensors, blocked hotend or mmu2 sensor (filament strings). I would clean all elements and check the sensor functionality. I have attached an LED on the extruder sensor and on the MMU2 sensor to visually check the sensor status. This makes the work a little easier.
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: MMU runs filament backward when loading?
As a bit of an update. I unplugged the MMU2 and am using it as a straight MK3S printer. It works perfectly.
RE: MMU runs filament backward when loading?
I had shorted the hotend thermistor changing a nozzle..mea culpa, so I had to change the main board. I verified the correct software and experienced the problems described. I have been through the setup all over again. I ran the manual test to sense the correct IR sensor. If I hadn't had this running 'nicely' for the last month or so I would just trash it, but I know it CAN work. And when it it does, well, a comparison to sex comes to mind. 🙂 I'm going to catch up on a backlog of printing to do and then return to this in a week or so. It just seems like it is out of sync or has a problem knowing how much filament it HAS pushed out and then pulls too much back.
RE: MMU runs filament backward when loading?
have you try the ir calibration?
look on the mmn handbook paragraph 7.1
i solved with this
RE: MMU runs filament backward when loading?
I had shorted the hotend thermistor changing a nozzle..mea culpa, so I had to change the main board....
Purely informally - how did that happen?
It happened to me once when using a wrench and that's why I built a tool to hold the heating block.
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: MMU runs filament backward when loading?
@iuri-s
Yes. As noted in my post, sensors are correctly aligned and indicating correctly.
RE: MMU runs filament backward when loading?
@karl-herbert
Well I didn't do it with something so pedestrian as a wrench! 🙂 *I* spend US$30 on a SPECIAL wrench..and did just what you did. The Z-Catch or something like that, every picture I ever saw had the block holder on the narrow side. Being wrong is a sideline for me. 🙂 It was pretty lightening..and a mainboard later here I am. PRIOR to the smoke letting the MMU2 worked just fine. So install Prusa Mainboard, reload software, go through the manual steps to correctly identify the sensor, both FINDA and IR sensors aligned and tested. Filament is pushed to the extruder, extruder begins taking it in (IR indicates 1) Extruder stops, back tracks (still 1) MMU takes it all back (IR=0) and repeats 2 or 3 times before MMU load error.