Ninja TPU stuck above the nozzle so i cant load new filament
I tried the Ninja TPU and it got stuck, i tried to unload but it ending with breaking somewhere inside. I took the nozzle out and heated that separately and i could push PLA throught that. Put the nozzle back, still cannot load. The filament loader tries and then makes a banging sound (not that load though), i try to push PLA in but it doesnt get to the point where the sensor register it. Thats why i believe there is some TPU stuck between the nozzle and the loading zone.
What should i do
RE: Ninja TPU stuck above the nozzle so i cant load new filament
If you heated it with a torch or something and then pushed PLA thru you've likely got PLA jammed in there now. The tube above the heat break cannot have melted filament inside it as the heater doesn't heat that area.
You could also try a drill bit there same size as the id of the tube and by hand turn it to try and drill out and plastic stuck in the metal tube.
Some have also torched the nozzle to burn the plastic out. Or just throw it away and get a new nozzle.
If you ever get a jam like that again the best thing to do is to just heat up the nozzle in the print head like normal and use PLA or something to manually push it thru by opening the idler door. You should never heat the metal tube above the heatbreak.
To find where exactly where the jam is disconnect the PTFE tube and attempt to load - it will fail - mark the filament (sharpie) at the entry point, unload and externally align the filament against the mark to see how far down the blockage is.
*IF*, and only if, the trouble is in the heat zone: open the idler door locate the top of the nozzle tube, heat the nozzle to 10° above the working temperature for the TPU, take 30-40 cm of PLA and push it down the nozzle tube by hand completely bypassing the gears. Push it slowly at first, it should extrude, perhaps with some resistance - push harder until it is extruding as fast as possible then finish by immediately pulling it out as fast as you can.
Cooldown, reassemble and try loading as usual.
Cheerio,
RE: Ninja TPU stuck above the nozzle so i cant load new filament
I found out via tech support where the problem was. The white Ninjatek TPU had made a not around the gear.
I was advised to pull it out with pliers - that was possible - although some force had to be used
I tried again with another TPU - got stuck again. My print head made "fishing boat" sounds "duck duck duck duck" while trying to load. Clearly stuck.
I took it out again
I noticed my gear was not all the way in, and the TPU got stuck in the gap. I dissembled the gear again
I noticed the 3D printed filament guide had a lot of debris, and grains in the holes. I cleaned out the holes with a fitting drill bit, used a fine file to remove other residues, and I added a 45° chamfer for where the filament goes in - just to help it (because it had problem loading)
I put it all together, in following order.
1. First the 3 gear assembly on the stepper motor pin. Noticed that the stepper motor is kind of loose, so one have to take very much care when putting in the mounting screws that one doesnt make it tilt more in one direction than another. You have to thighten the screws sequentially and in small increments (thighten screw 1 a abit, then screw 2 , then screw 3 and then back to screw 1 - but that is not for now thats the final step)
2. I made sure the gear was all in - so the gap between gear and stepper motor in the pictures above was removed.
3. I put the black filament guide in
4. I now had the black cover cap with the large brass gear, and i gently wickled it on, so i took care i wouldnt pull out the 3-gear-assembly from the position at the stepper motor (trying to avoid to make the gap reappear)
5. Then screwed the screws in as described in point 1. One by one in small increments.
6. Did gear calibration.
Tried to load TPU again - went smooth no isssues.
Printed TPU - no issues.
Ok my first repair - the tech support was really good and very supportive.
Lars
RE: Ninja TPU stuck above the nozzle so i cant load new filament
I would like to retract that i fixed it. I didnt. Tried the soft Ninjatek TPU again today - got stuck - fixed it by pulling out the filament. Tried to load Prusa TPU 95, also got stuck, now i had to remove the gear to get it out. Assembled again. I now carefully watched how it load TPU by opening the locker on the gear box. I can see that TPU tends to turn inward against the stepper motor - and then it gets stuck. I made sure it was as good as I could aligned towards the lower filament guide, closed the locker and kept purging - that worked. So no magic just manually positioning of filament in the head.