Thursday, February 07, 2008
PTFE slippage
Some people have been having troubles with the PTFE tube slipping out of the extruder. I have done a design modification to fix this: I put a couple of 3mm holes sideways through the clamp.
You put the PTFE in and clamp it gently, then run a 3mm drill down those holes. A couple of 3mm pins (or screws) placed in the holes then prevent the PTFE moving downwards under the force from the screw drive.
I've run this with the clamp screw just finger tight, and it all works solidly.
You can do this as a retro-fit: drill the holes (take care to miss the central hole where the polymer filament runs...) and put in a couple of pins.
I've checked in the modified clamp design to the repository.
