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.