Idler Issue

I'm so so close to printing up properly now - but have run into one last snag... The idler seems to be the issue -

When I'm trying to print, the filament isn't being fed fast enough... Then when it retracts the filament, it tends to retract too far and pop the filament out of the extruder...

I've tried switching up the springs and the bolts that go into the idler... right now I'm using just 2 bolts and 2 springs... should I be using more?

What can I do to keep the filament from retracting too far? I have retraction speed really low (like 5mm/s) in skeinforge and retraction distance at 0 - but it's still retracting... oozbane is off... most everything is off, but I haven't been able to get it to stop the retraction...

Really the only way it prints close to how it should is if I press down on the filament... the motor is strong enough and it is spinning, but it's just not feeding the filament down the way it should.... should I crank down on the idler? Try to get it tighter so more of the hobbed bolt grabs the filament? I've tried different things, but nothing seems to help just yet...

are the bolts teeth clean or have they become clogged with plastic? that would indicate a jam at your hot end, could be not enough plastic is melting in time to be extruded, too low a temp or too short a melt zone. or maybe the melted plastic is finding its way into gaps in your hot end, joins if you have any and solidiying. if you get plastic in the teeth you have to clean it out to be able to extrude again although clogged teeth would still be able to retract the filament pretty easily. If you tighten your springs on the idler too much it will start to strip the plastic and clog the teeth regardless of your hot end, doesn't need super duper pressure on the idler just enough so the teeth sink into the filament.

Thanks for the help - I'm using Makergear hot end and it seems to be working fine... but I do think that the hobbed bolt's teeth might be a bit clogged... I'll clean that out tonight when I get back from work and give it a go... thanks for the advice-

maybe you tried too much pressure on the springs. if you still have trouble i would undo the springs completely, heat to processing temp and then yank the filament out of the nozzle and extruder and if you are having jams the end kinda molds to the shape of your nozzle and can maybe reveal your problem. although makergear have a pretty good rep around here.

When I first put my makergear extruder together I installed the idler piece on backwards- the idler block was flush with the rest of the extruder housing and therefore the springs weren't able to apply force to the filament.

It's odd that the motor is retracting if you have those settings turned off in skeinforge, can you give us some more information about your setup? I've got a makergear 1.75mm extruder, use skeinforge 41, and run my machine using repsnapper and ramps1.2, with sprinter firmware.

My extract speed is 8mm/s, and retract distance is set to 1.0. I would think something is pretty wrong if your extruder is backing the filament out of the extruder- that would be a distance of 30-40 mm at least. Is your stepper motor wired up in reverse?

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Germanicus