MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
I am in the midst of redesigning the Bunny and Bear, Short Ears extruder to use the MK3S sensor.
https://www.thingiverse.com/thing:3606189
I am tempted to also make it MMU2S compatible without the sensor "chimney." I'm testing an alternate mechanism INSIDE the extruder to take the place of the sensor chimney. No chimney, but still sense the Bondtech gears separating. That will also allow unfettered opening of the idler door.
The scheme presently requires swapping of pieces inside the extruder to convert from standalone to MMU2S sensing. What I mean by standalone vs MMU2S....
1. filament sensed above Bondtech vs
2. sensed upon Bondtech contact
Swapping out parts inside the extruder when installing the MMU2S is not a terrible ordeal, but it would be nicer if users did not need to swap anything at all. One could simply leave the MMU2S sensing in place full time. That would require the equivalent of the printer being able to run standalone with the chimney installed.
Hence my question.
Can one have the filament sensor chimney in place and use the printer as if it were a non-MMU2S printer?
RE: MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
Can one have the filament sensor chimney in place and use the printer as if it were a non-MMU2S printer?
You can... but if your filament runs out it won't sense until it's past the gears, and then there's nothing to pull it out anymore...
RE: MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
Thanks.
That wouldn't be a good scenario on single filament configurations.
RE: MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
Thanks.
That wouldn't be a good scenario on single filament configurations.
Plus autoload wouldn't work very well. I.e. the user would have to push the filament into the gears for the printer to notice and start loading.
I'd actually love to have both sensors at the same time and modify the firmware to have better knowledge of where the filament is based on both sensors. This would improve loading (the printer would know the user inserted the filament and would know when grip was established, too), unloading, filament runout, etc, etc.
RE: MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
When my MMU came I was starting from a plain MK3. I upgraded it to the MK3S and ran with the filament sensor turned off (don't know if I needed to do that) while I got the printer dialed back in (bed leveling, Live Z, etc..). I did not have any issues, but I wasn't doing any prints where running out of filament was an issue.
OK going with separate configurations for single spool vs MMU2S
It was more work, but I've completed both sensor styles for the upcoming Bunny and Bear "Short Body" MK3S extruder. It's been an interesting project shoehorning everything into less volume than Prusa has available. Remember, the BNB extruder pushes the motor INSIDE the main extruder body. Things must be more compact. For instance I only have space for 1 magnet. Despite that I also wanted to get rid of that ugly MMU2S chimney.
Bunny scientists did it. Final design prototyping is nearly complete. Test parts have verified both modes of filament detection. Probably a could days away from Thingiverse release, but here are some previews....
In single media mode (sensing above the Bondtechs), filament deflects a bearing above the Bondtechs. The bearing swings interrupter armature in/out of optical path. One magnet pulls bearing into filament path.
For MMU2S, you can still attach the Prusa chimney. I've kept compatible screw hole pattern for that and will supply a levered idler door. Alternatively, one can switch to my INTERNAL MMU2S mode sensing lever
To switch modes, you remove the normal armature, insert the internal sensing lever, insert a filament path plugin and move the magnet to a different position. As idler door moves in/out with Bondtech geers, how far it presses the sensing lever changes. The lever is continually pushing against the door and rides on a bearing tucked into the idler hinge. Spacers keep the lever independent of the idler door. Fine tuning of the sensor is via a screw on the idler door. This gets rid of the external chimney and idler door is free to fully open for service.
RE: MMU2S Filament Sensor Chimney - Can you install it and print WITHOUT the MMU2S?
The beta files are up on Thingiverse. Will be working on the instructions - it's a bit more involved build than the stock extruder.