This is a derivative of the Plastruder MK3 design I've been working on. The goal is to make the plastruder into a printable design that can be made on a MakerBot. I also wanted to take on an ambitious project to put the new AOI plugin, MetaCAD through its paces. Learn about metacad at http://www.metacad.org
This extruder design uses 5 printed pieces: two halves that bolt together for the housing, 2 dinos to put it at the right height for printing, and a simple insulator retainer to keep the PTFE in the right spot. The rest of the design is mostly the motor, heater barrel assembly, electronics, and a 625 bearing to provide the pinching force. It has yet to be tested, but ideally it will be simpler to put together, as well as a sturdier design with no squeaks! I've printed all the parts on my travel bot, and as soon as I get home, I'll be assembling them and testing them out.
A few design notes:
- no more layered construction! that was a hack to make it laser-cuttable. new design is two halves bolted together. one half holds the motor + filament, the other half holds the idler wheel.
- idler wheel switched from acrylic + 608 bearing to a single 625 bearing. smaller, more compact, and nothing but a nearly indestructible bearing to break. should be quite a bit more consistant
- 4 adjustable screws with captive nuts for setting the pinch wheel tension. you'll be able to adjust it on the fly, without any sort of dis-assembly. hopefully the abs will act as a sort of spring as well
a few things i'd like to change yet:
- rotate the captive nut slot on the right-housing to be in-line with print direction for a better finish.
- switch the captive nut / bolt head holes between right and left housings to improve print quality for both (adjust on right side instead of left side)
Haven't tried it yet, but the process will be something like this:
- bolt motor to left housing
- bolt washer + 625 bearing + washer to right housing
- insert captive nuts in appropriate places
- insert filament
- bolt left and right housings together, and clamp down on filament a bit
- bolt on heater barrel assembly using captive nuts
- bolt left and right dinos on... m3 bolts directly into plastic (hope it works!)