Greg's Accessible Extruder - Spring Tension

[old man emu]

Can anyone help me with the correct tension on the idle bearing assembly on a Greg's Acccessible Extruder?

I can't get my filament to feed between the hobbed gear and the idler bearing which is spring tensioned. Everything else is OK and the extruder is not blocked.

What is the distance from underneath the heads of the screws that have the springs on them to where they enter the idler body?

Old Man Emu

[3dkarma]

A lot depends on the strength of the springs. Are you using 3mm or 1.75mm filament? 3mm will need a lot more tension. I found the correct tension iteratively - extrude a bit, tighten slightly, rinse and repeat.

If you inspect the filament after you've tried to feed it through, can you see a depression where the hobbed bolt has ground away the plastic? This is an indication that your tension is good enough but something else is blocking. If you can push the filament through and it extrudes easily by hand then the Wade's will be able to push it through. If not, something else is going wrong.

I assume the gears are turning - if not, chances are tension is too high for the torque of the motor to overcome.

Sorry I can't be more specific and if I'm saying stuff you already know, but it's hard to recommend a specific distance when the strength of the springs can vary so much.

[old man emu]

Thanks. I employed those two experts, Trial and Error, and have got things working nicely now.

OME