Spooljoin - Can't retract old filament?
Using an MMU3 and a MK4.
I was using the spooljoin feature for the first time with an old spool of filament and a new one. The FINDA successfully detected that the old filament ran out, but when trying to purge the old filament it seems as if it can't retract it. I tested it again and neither times was it able to do so. What do I need to tweak to ensure it can still grip the old filament? Do I need to adjust the FINDA sensor, or increase tension in the idler?
RE: Spooljoin - Can't retract old filament?
I face the same problem. I tried playing with the tension screws, but so far with no luck. Spooljoin doesn't work for me.
When not using Spooljoin, it prompts me to remove the filament from the MMU front and the MMU moved to another slot, which means it wanted to retract the filament back in the MMU to eject it, but it is still in the hotend and nothing in the MMU.
It seems one it detects the filament ran out, it cannot grab it anymore, which is strange, because the extruder should be able to push it back to the point the MMU can grab it.
Anyone has an idea to that? Apart from the tension screw, there's not much to tweak, isn't it?
RE: Spooljoin - Can't retract old filament?
Any solution yet?
I‘m facing the same problem.
RE: Spooljoin - Can't retract old filament?
I face the same issue and I noticed that the retracted filament has a slightly thicker end point. This gets the filament stuck in the tube and prevents it from being retracted by the MMU.
Might this also be your problem?
I'm still looking for a way to get rid of this thicker end point. Any suggestions are welcome.
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RE: Spooljoin - Can't retract old filament?
Same problem on MK4S and MMU3...
In my case it appears that the filament gets stuck on the PTFE connector on the MMU3, it want's to get pushed back from the extruder, but it won't enter the "hole" in the connector and jams.
RE: Spooljoin - Can't retract old filament?
I just don't understand why MMU is trying to stuff the rest of the filament back into the input tube. After all, the end of the filament or its shape cannot be influenced by the user, and that's where the filament gets stuck. And yet, in my opinion, there is a solution that would cost one more toothed pulley and one small bearing. In the MMU body on the far right, there is a large hole leading out of the MMU body. Even in this position, the selector stops after initial initialization. The selector could easily aim there and then throw the rest of the filament out through this large hole with the help of the sixth roller. And there could be an additional groove that takes the rest of the filament away from the printer so that it doesn't fall onto the printing plate. I'll try to look at it and if it's at all possible, then I'll suggest this modification to the developers.
RE: Spooljoin - Can't retract old filament?
I too have a problem with spool join. Tried 3 times and 3 times failed. Always due to unable to retract old filament. Last time I waited for spool end and cut the end of filament to be straight. But still, it couldnt retract it.
I had to put out ptfe tube from extruder and then push the filament little. Then MMU grabbed it, I put ptfe tube back in and all went well.
I dont know whats the problem. It seems to me, that finda in mmu3 is after the grabber pulley. So it physicaly cant grab it back, when finda finds filament has ran out.
But that would mean, nobody can use it. Maybe it is on the edge, so for some tighter setups it can work. Dont know.