Bowden Nozzle adapter for MMU Extruders
Hey Mates,
Working on getting my Mk2S with MMU back into my enclosure. one thing that is proving to be a chore is getting the filament from the spools (on top of enclosure) to the extrudes. Wanting to try putting some bowden adapters at filament entry point. Putting tubing directly into the hole pinches teh filament, which is preventing loading for me.
With that said, I am also a 3D artist. Are we able to print the 3D printed components of the MMU. More importantly, Id like to get the model of the extruder main body into 3DS Max so I can model an adapter right on the current model geometry. I would them make the adapter SLT open source, if that is allowable.
Any help on this point? I am trying to make said adapter by taking measurements now, but that region of extruder body is a bit convoluted and slightly different from the right and left sides.
Re: Bowden Nozzle adapter for MMU Extruders
I have the same issue, though my filament comes through the bottom of the enclosure (lack). Without some kind of guide the filament will run into the X and Y axis cables. I've placed a holder a bit above the bed that the filaments now go through, but it makes an S curve that is obviously not ideal. PFTE all the way to the extruder would make things much better, though i'm a bit worried what will happen when the slack is fed back through the PFTE, though I'd have to try it to see the effects.
Re: Bowden Nozzle adapter for MMU Extruders
I printed some simple clips to attach some PTFE to the extruders and then run the tubes out of my enclosure. However, I've had a couple of problems with this setup. First, sticking the ptfe tubing to my clips has been a massive pita. I'm currently waiting on some chemical prep stuff (Loctite 770) for another go at making that work. Second, when my filament spools run low, the stepper seems to have trouble reliability moving the filament to the hotend, possibly because of the extra friction of the additional ptfe tubing and having to turn the spool more per step. I'm guessing here but removing the extra tubing certainly fixed the problem. Still tinkering.
Re: Bowden Nozzle adapter for MMU Extruders
OK, I designed an adapter to allow me to attach the Bowden connnector to the Prusa MMU extruder housing,. Available at Thingverse:
https://www.thingiverse.com/thing:2577668
Feel free to use it as needed. will post this to its own thread.
Worked for me. printer is now in its enclosure and top-fed via tubes through the roof to the Bowden connector adapter. More testing is needed, but so far, so good. I still have to roll the filament back when the printer is Unloading the Filament. maybe can rig up a separate extruder motor further upstream to help with this...but that is a problem for another day.
enjoy!
Re: Bowden Nozzle adapter for MMU Extruders
Nice!
Re: Bowden Nozzle adapter for MMU Extruders
I tried long PTFE tubes like this before the MMU and I found that it was adding too much drag to the filament pulling and might be too much for the extruders, might depend on the quality or diameter of the PTFE also.
Re: Bowden Nozzle adapter for MMU Extruders
Yea, I also have those concerns.
The real problem is retraction when switching filaments. Pushing the filament back when the spool just sits there.
Still testing. So far, it’s working fine with PLA on prints with 2 filaments.
However, TPU doesn’t even work for me when it’s out of the enclosure and the tubing removed (between the spool holders and the extruder). Haven’t figured that one out yet.
Re: Bowden Nozzle adapter for MMU Extruders
Have you guys considered using 4mm ID bowden for the reel side of the extruder, and splitting the length so that you dont back feed all the way to the reel on retractions??
the larger tube would impart less friction.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Bowden Nozzle adapter for MMU Extruders
I put passthroughs on my enclosure and have tubes the just butt up against the inlets to the extruders. I thread the filament through an M3 washer.
When extruding, the filament and tube get pulled toward the extruder until the washer makes contact. Then the filament comes through alone. On retract, it pushes the filament out and there is no force to push the filament all the way back onto the spool. Works great.
Re: Bowden Nozzle adapter for MMU Extruders
The actual problem for the Nozzle Adapter is switching and the spooling of the filament over the adapter, and the fix functions fo the MMu extruders, it is really very much difficult to get a clear concept on it, I got some supports from Canon printer technical support for the topic, it is really very helpful, you also can browse it, to know more information.