Quote Originally Posted by curious aardvark View Post
Sebastien has used a fariyl simple modification on his printer and reckons it prints ninjaflex really well now.
Used one of the little plastic ptfe tubes that sits inside the heater block. You insert it between the top feed hole oin the extruder and the feed hole for the heater. carefully cut out the section by the feeder/hobbed bolt so the teeh can still engage the filament and the tube doesn't get caught by the teeth.
Essentially it stops the filament from flexing and getting wrapped round the hobbed bolt and redirects it straight to the heater block.

Simple and ingenious :-)
That's exactly what I did. Takes all of 2 minutes to drill and fit the tube. Now I can print ninjaflex and other tpu's easy peasy.