High-force extruder?

I've recently been having problems with my extruder. In particular, the gear will strip the filament, or will squash it and cause it to jam.

I have a Bowden setup with Airtripper's extruder, a MK8 drive gear, a 0.35mm J-head hot end at around 210C, and 1.75mm PLA. I generally print around 125mm/s (Delta FTW!) but I've recently slowed down to around half that.

The solution seems to be a new extruder design which doesn't push the filament unguided as far as Airtripper's does. Is there a design out there that can handle higher pressures and speeds -- perhaps 300mm/sec via 0.35mm hot end? My motor can handle it, and I think my drive gear could if I were to turn the tension up high enough.

The force on the filament is indeed limited when it starts crushing the material. The teeth in the drive get blunt over time but of course it helps to clean out the plastic as well.

Ive never printed such high speed but I have an idea for an extruder with double drive gears, if you have metal working capability we can talk

What sort of metalworking? I can't make a drive gear, but there's a lathe I might be able to hijack. It might even be possible with just a printer.

How quickly do the teeth generally dull? I've had my machine for around a year.

why not try this?, it increases surface area that pressure is applied while keeping feed stocks shape

[www.thingiverse.com]

it is for rostock ectruders, but it could be modified

Edited 2 time(s). Last edit at 09/29/2014 10:30PM by jamesdanielv.

I like the looks of that. How exactly does it get so much more force without squashing the filament against the drive gear?

@ epicepee , you probably print with 3mm material am i right ?

go down to 1.75 and you can reach those speeds easily
Just look at THIS (and THIS at minute 33) for example, Nema14 (1,8kg) 10:43 geared Extruder on 8mm Hobbet bolt, burning ABS at +400mm/s onto the bed

And don`t use full-metal hotends, their melting transition zone is normally just too long.

Chri

Edited 1 time(s). Last edit at 09/30/2014 07:08AM by Chri.

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[chrisu02.wordpress.com] Quadmax Intel Delid Tools

He inscrease the surface of the part the bearings grap onto. Not a bad thought. It seems to work

I print in 1.75mm. Is there anything smaller?

Also, how exactly does it add force for the bearings to grip the filament better, since the bearings aren't the part driving the filament?

Edited 1 time(s). Last edit at 09/30/2014 11:34AM by epicepee.