I have purchased a spool of ninja flex and I have only had one “successful” print. The filament seems to be jamming. The extruder does not get clauged but the filament tangles up. Does any one have any tips one how to solve this problem ? My ROBO R1 is stock I have made no modifications.
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Unfortunately, the distance between the hobbed bolt and the entry hole near the heatbreak is too long for Ninjaflex, Ninjaflex filament. It doesn’t mean it can’t be done, but if you’re running it at speeds over 25mm/s it might not work. Using a e3D v6 with their bowden entry on direct drives makes using flexible filament much easier because the tube guides the filament immediately after it leaves the hobbed bolt.
If your having issues with the spool tangling I had that problem with some pla on my robo. I wasn’t able to completely fix this issue but I did find something that helped. I am still using the stock spool holder which the holder diameter is way smaller than the spool diameter, so I was able to source a roller bearing (25x32mm) to take up some of the space. Then I printed a sleeve to go over the bearing to take up the remainder. This made the spool feel buttery smooth while rolling which helped reduce the strain on the extruder feed mechanism. Hope this helps, unfortunately I don’t have any pics right now but I can post some when I get back on Tuesday. Otherwise if its tangling after going through the extruder then I would check your z axis offset. Sounds like it might be a little high. I’ve got my machine set to 1mm but I’ve read that these machines can be anywhere between .6-1.4mm
I’ve had the same problem with Polyflex. It keeps bunching up just after the hobbed bolt. The only way I could get it to work was with an E3D Volcano, and a. 8mm nozzle. Temperature up, feed rate and movement speed down. I could feed faster with the 1 . 2mm nozzle, but the temperature would drop off until whatever program I was using would stop the print. I used both Mattercontrol and Simplify3D, also with a Robo3d R1. I bought some insulating tape from Aliexpress for the hotend, but haven’t had a chance to try it out. Good luck!!!
Is the tangle before or after the extrusion motor?
From my experience a good way to fix this problem temporarily is to put a bit of PTFE tubing with a groove for the hobbed bolt from where the bearing is, all the way untill the extruder. Than the there is no place for the plastic to bend because the hobbed bolt will push it through the tube.
Defyus
7
I built a external direct drive and bought a e3d extruder with Bowden attatchment. But note you will have to callebrate direct drive to extrude the right amount of filament.
I have the same problem with Tpu… I simply stopped using it.
Do you think you can post a picture ? I have a costumer who needs to a part out of ninja flex. So a temporary fix would work for me .
i have ninjaflex here but haven’t had the time yet to try. But I can tell you the ROBO R1 here states 7 degrees too much on the extruder. So I print Pla in the 190 - 195 range to compensate for that. You can check it quite easy: Compare your bed temp with your extruder temp when you switch on. Take your bed temp for true. (my bed temp equals the room temp so I trust it, since then I haven’t seen burned spots and bad overhang performance in my prints)
thormj
11
The problem for flex feeding is the large gap between the bottom of the hobbed bolt and the entrance to the hole in the extruder frame. Some people put a small metal bushing (from a ball point pen) in the gap. I removed everything and drilled the extruder out so I could put a Teflon Bowden tube from the hobbed bolt all the way down to the entrance to the hotend.
I still have to run 210c & ~20 cm/s (as opposed to 205c & 60 cm/s for normal PLA). Looks like I need to clean out the shavings again…
