Butterfly Gouged Into Print Bed

Bowden Extruder Troubles

Our Huxley hot end kept popping out from the clamp, which was warping under the heat, and ramming into the print bed gouging out designs in the plywood.

Several iterations of clamp design later and we’ve settled on a beefed up version that seems to cope with the force of the extruder (even when I had set the Z STEPS_PER_MM to 20% of what it should have been).The original design for the extruder bracket used only one bolt to tighten the clamp relying on the plastic flexing to provide the clamping force.

Bowden Bracket

Unfortunately under the pressure the clamp bent out of shape, a problem which was only made worse by the heat of the extruder, and being deformed could not exert the required force to keep the nozzle in place.

Original Bowden Nozzle Clamp Bent Out Of Shape

So I broke our OpenSCAD and redesigned the clamp to be in two parts, utilising two screws to clamp the nozzle with even pressure.

Here it is printed in PLA:

Bowden Nozzle Clamp Redesign No 1

This was much better, and allowed us to put in some sandpaper around the PTFE of the nozzle to increase the friction. Sadly though before too long the clamp part had also succombed to the heat.

Bent Clamp Piece Top View

Bent Clamp Piece Side View

Back in OpenSCAD I beefed up the clamp part and added a ridge on opposite sides inside the hole. We also cut corresponding notches from the PTFE, which had already been started by using the M3 bolts to fix the nozzle in place for the original Wade extruder.

Finally, it worked like a charm! Here it is in place on the X carriage waiting to be bolted down and the Bowden Cable clamped in place.

Bowden Nozzle Clamp Redesign No 2

The Wade extruder at the other end of the Bowden Cable uses the Printable Bowden Wade Adaptor by aka47.

Wade Extruder with Bowden Adaptor

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