Direct drive Extruder gear

I’ve been on the lookout for the same kind of gear that makergear uses on their extruder for quite a while. Not the gearhead for the motor, but the actual part that bites into the filament.

I found cornwall model boats this morning, and I ordered a few from England. It appears to be a fitted end for a model boat u-joint, but it looks like it could easily work and they are available in both 5mm and 1/4″. I have a vague idea of using two of those on the shaft of this motor to make a dual filament bowden extruder.

The point of that would be to print the same part on the same machine twice at the same time. RAMPS has support for three thermistors and three outputs, so I could effectively double my print speed for parts that occupy less than half of the bed! An alternate idea is to use one RAMPS to control two machines, by either getting more powerful motor drivers or by getting twice as many. The only issue with that would be the 4 thermistor issue. Either printing PLA or some external circuitry could be fix that. I’ve been meaning to build up a bang-bang heated bed for some time now…

5 Responses to Direct drive Extruder gear

  1. I’ve also wondered about a more direct drive system for repraps. After using a Makerbot for the first time, i think I like the direct drive system better than a hobbed bolt set up… I’m really looking forward to seeing any progress on a dual bowden… Sounds great!

    I also just noticed that Makerbot sells their “drive gear”. I might need to pick one up and try to design an extruder around it!

  2. @matthew bennett
    Yeah, I actually have one of those drive gears. @$12 they aren’t too expensive, but the three I bought today ended up under ten, shipped. The motor I am thinking of using also has a 1/4″ shaft, and the makerbot one is 5mm.

    I’m thinking of starting out with one of these two
    and taking it from there.
    It seems like the one from jstkatz may be easier to double up on.