Well, over the last couple days I've gotten a few pieces in.
- The geared extruder based on Wade's design
- Full electronics set for the machine
- Copper bar and cartridge heater for the barrel
So here's a few photos:
First, the extruder. This is how I assembled it, I believe this to be correct based on the illustrations I've seen
Here's another shot of the underside with the thermal barrier and nozzle installed
Here's the electronics along with the copper bar and cartridge heater
And here's a closeup of the cartridge heater
Onto the technical stuff. When I got the extruder in, it was pretty much perfect aside from a couple slightly little imperfections which were easily cleaned up. I used a squared file to rasp out the inside of the thermal barrier mounting hole and the PTFE barrier fits in fully and snugly. Just need to modify it a little for the mounting screws and I should be all set. It has a very tight grip on the filament and I was not able to budge it no matter how hard I tried.
The electronics came in, they were quite nice. There were a few touchups I had to do on the boards.. being all SMT they were bound to have a couple little problems, and they did, namely not enough solder in a couple places and a chip cap tilted up off it's pad on one side. Otherwise they seem pretty solidly built. I'm anxious to get them up and running with the steppers.
Finally, I got the copper bar and cartridge heater in from McMaster Carr. The cartridge heater seems perfect for the job, and the copper bar seems to have all the right dimensions for cutting it to fit. I'm going to attempt to build the heat transfer assembly I sketched out earlier, and I'll begin on that next week. The heating through the threads seems to be the preferred way of doing it, so I'm going forward with this.
Currently I don't have a lot more work done on it due to being away this week, however, next week I may have some time with a MakerBot, so we may be able to get some parts turned out to get it going. I'll keep posting pictures as I get more things and set them up.