TPU

[Jon Bondy]

I have printed NinjaFlex in the past (once!) and am now trying MatterHacker TPU.  I tried an extruder temperature of 240 and 220.  I can get filament to extrude, but very slowly; and when I try to print, all I get is a series of small blobs with strings between.  I had to increase the hob gear pressure quite a bit to get it to work at all.

Anyone had better luck?  Was there a secret?

Jon

[RepRapper]

you are looking for a flexifriendly Extruder + E3D V6 or even better Prometheus hotend. 

[Jon Bondy]

Thanks, RepRapper.

I continued trying to make the regular Aluminatus extruder work.  The front part which contains the pressure bearing, extended too far back, which prevented the front part from rotating all the way back.  This prevented the bearing from fully pressing the TPU filament against the hob gear, so the hob gear would not grab.  I filed off some of the material toward the back which was causing the problem.  It is working now (although not extruding nearly enough).  I think I just need to tweak it a bit now.

[Jon Bondy]

Once I had sufficient pressure on the filament for the hob gear to work correctly, the extruder started working properly.  My next problem was getting the prints to stick to the glass build plate.  Test prints worked fine on bare glass, but once I tried to make a real print, it started to come off of the build plate during the print.  I tried hair spray, but that did not work.  I then used a glue stick plus adding a brim in the slicer, and then the print came out reasonably.  So, no need to switch to another extruder.