Detailed description of the problem: After a short while, say 30-40 minutes, the filament is no longer pulled into the printhead
Printer model used: P1S
Slicer settings used: Default
Type of filament used TPU Creality Type CR
I have no previous experience with TPU, nor with the use of the external spool, as I always have used the AMS, which of course is not possible with TPU.
The wire has been dried 2 x 5 hours, and came from a sealed package.
It sets of with no problems, but after some time it stops printing, but continues making all the needed movements with the printhead, no error codes, it just continues to run, but does not extrude. After the first issue I thought that the nozzle was blocked, and hence the next run was done with a higher nozzle temp. (240°>250°C). then it stopped even quicker. I manually pushed the filament ito the tube, and it started to extrude again, so my conclusion was that the gears are slipping or something on the soft filament.
Fans, are ON. door open.
I printed this with de default settings for TPU, and I know a member which has the same machine and has good results with the Generic settings.
Is there a possibility to increase the pulling power of the printhead?
I feed this from the dryer right next to the printer, and use a short guiding tube. The filament is pulled from the dryer with no resistance, as it has roller bearings in the bottom, so it is extremely easy to pull it from the box.
Or should I just LOWER the nozzle temp?
Any suggestions are welcome.
Check the spool to be sure the end of the filament did not slip under an adjoining wrap, creating a knot around the spool. This sort of tangle might let the filament come off the spool easily at first, but gradually tighten as the print continues.
Thanks for your interest, and I do know this type of problem, but this is NOT the case now, therefor I stressed above, that it is extremely easy to pull the wire from the roll, even after it had stopt extruding. This make filament is very nicely spooled up, though it is also the first time I bought this make.
If I were to setup my P1S for TPU, I would try to hang the roll at least 20cm ABOVE the machine, with the glass off, no tubing, feeding directly into the extruder. You said you run from dryer to machine. Is it set up like this, or another way?
I used the dryer sitting next to the printer, on the left side.
In the meantime I found that there are only 2 holes for the wire to exit the dryer, and these are in the top lid. I cannot get a hole somewhere in the bottom half, because the heating pad is there over the full width and covers half a circle.
I guess that I need to find or make a container without a dryer element, dry the filament first again and then insert that in the container together with boxes silica, to keep it dry during printing. Any other suggestion?
If the filament is warm coming out of the dryer, it can stretch while being pulled causing it to be thinner and the extruder losing grip. Take it out of the dryer and let it cool down while in a sealed container/bag with dessicant. Try printing with the filament at room temperature.
on makerworld, search for p1s top mount spool holder by ATSF. I had the same problem, and that solved the whole issue. Also, you dont have to have the bearings for the print
Thanks for all responses, which have been very helpful in finding and confirming my issue.
It appear that this is a very common problem, but if you do not know what causes it, it’s very difficult to find a solution.
The provided suggestions cannot be implemented here since the printer is located in a cupboard, but your responses resulted in finding a solution which works for me, I hope.
I enclose a couple pictures of my (temporary) solution: Placed roll of filament on a shaft with bearings, put that in a warehouse tray and drilled a hole through the top of the cupboard. I will then put some silica in the tray, and place a bucket over it during printing, hope this works.
A link to what??
In case you refer to the 3 pictures above: no I did not document this any further, as it is a very specific , and untested (yet) solution, with items I had available, or made on my lathe. I merely placed this to let contributors above know what I had done so far.
I think that solution looks great. Let us know how it works out. Look out for the telltale “too high of tension pulling the filament off the reel” - shows up as ragged underextruded layers that tend to resolve themselves. But I think you have a good easy path.
To conclude this story, I can now report that my solution to this issue did work. The print of 10 hours was completed without any problems and to finalize this I’ll add a couple pictures, taken just before the finish @415 lines high. It is a model 1:14 conveyor belt, which is just fitting my P1S.
Thanks for all the messages putting me in the right direction to resolve this!
