With my X1c and AMS, I have a splitter in the back to load TPU from the side. Loading and printing work fine but when I go to unload, the TPU tends to get “stuck”. Sometimes it just takes a good bit of force, sometimes I have to power off/on to restart the unload process and sometimes I even have to remove the PTFE tube from the top of the extruder to get the filament free.
I’m not sure if the unload procedure is heating the TPU too much and causing it to melt and glob but it definitely isn’t cutting clean and pulling free like it should.
Anyone else run into this or have any suggestions on how to make unloading of TPU easier?
I have printed TPU once, but no problems with retraction, but I have had 3 other problems: Filament knife hangs, filament could not be extruded, filament could not be retracted. When the print head moves into position to change filament, I supply cooler outside air to the print head there. My problems, even with simple colour changes, have stopped. It’s the solution for me because I leave the glass plate on the printer because of the AMS and the door remains closed. The print head definitely gets too warm inside, especially where the filament should no longer be warm, namely in the extruder and above the nozzle.
Try printing the short stack filament guide, or any one of the others to help with the PTFE entry into the extruder.
Also, change you filament cutter, it may be dull. Personally I’d like to find out how to speed up the cutting action, as with TPU and some other infused filaments (i.e. harder to cut), I think it’s pushing the filament away before cutting as it moves so slow and this can cause it to cut on a slight angle which in turn, can get stuck sometimes.
I have a filament guide on it. I could change the cutter but the printer is only like a month old or so. The issue really seems to be that the hot end is too hot when it cuts the TPU and the filament is just melting. When I can pull it free, it’s not cut clean and comes out stringy at the end. When I had to remove the PTFE from the extruder to remove the filament, the end of he filament was globbed up and couldn’t even fit in the PTFE tube.
Honestly, I’ll have to try next time manually pushing the cutter before the extruder heats up at all to see if that results in a clean cut.
Are you waiting for the extruder to unload the filament before trying to pull it out the rest of the way? I found that if I put some tension on the filament before it starts to unload, it comes out easier.
I actually starting pulling on it as soon as the Unload process starts. Once the hotend heats up and it goes through the cutting motion, I continue to pull harder and I can usually get the filament free but it takes quite a bit of force.
Mine cuts the filament but then does a sort of cold pull that brings a blob along for the ride. It’s always been successful but sooner or later, I feel like it’s going to bite me. What would happen if you pushed the cutter lever in by hand with the power off then just pulled the filament out by hand? Would that confuse it?
I don’t think you’ll be able to pull the filament out through the extruder gears with the power off. But you can still cut the filament manually and use the menu controls to back it out through the extruder with the power on.
I think the cutter blade would be better if it was a V shape instead of flat
