Getting closer

I finally got the extruder to grip the filament. I Dremeled some ratchet steps into the stepper's shaft, and now it will extrude thread out of the nozzle at about 25mm/minute. It can do 40mm/min, but it slips a lot then.
It extrudes, sort of. I can get it to go for a few minutes, but then it stops. I tried making the test part, but when the head stays in one place too long, it starts slipping, and then won't extrude again until I push the filament down for a bit. I'll have to play with the Reprap software settings. It's also slow as molasses. It didn't even finish a layer when I let it run for 4 hours.

The almost complete RepStrap frame.

Rear view of the X carriage. When the thing starts working, perhaps I'll replace all that wood with reprap'ed parts. The blue lines conect to the opto endstops.

Here is the extruder mounted to the carriage. It's a tight fit, by design, but that may haunt me later on.

Assembled extruder. This is my first extruder design. It's pretty much the minimum size for a pinch wheel extruder. This may work against me.


Without the motor, you can see the 3 layers of acrylic. The holes at the top of this picture mount the unit to the X-axis carriage. The layer closest to the motor required a larger hole centered on the motor to allow for the raised center of the motor. The other layers have just a small hole for the shaft.

The bearing is bolted to an aluminum plate, which, with the motor, sandwiches the acrylic. There is a guide hole for the filament that leads between the bearing and the motor shaft.

My RepStrap almost works...

My RepStrap almost works...
I have some pictures at my other site. I'll start posting here to share my progress.