A copper tube and bowl hold melted chocolate which is fed to a drilled-out welding nozzle via an auger made from a drill. The heater is a standard nichrome wire and fire cement, along with a 100k thermistor, connected to the standard RepRap arduino electronics.
Drive for the auger is provided from a Tesco Value 3.6v rechargeable screwdriver. Currently, this is manually operated as I'm having a problem driving the motor using the PWM DC driver.
The heater took a while to heat up, but the entire apparatus reached target at 60 degrees C. Shoving a few chunks of chocolate in, it melted very quickly.
Extrusion worked much better than I expected: when the motor was off, there was a very slow drip of chocolate through the 0.6mm welding tip (approx 1 drip every 5 seconds).
With the motor on, I was able to extrude a steady stream at several mm/sec and drew some lines on the plate. With the motor in reverse, chocolate was actually sucked back up the nozzle!
- Drive the motor from the RepRap electronics DC motor driver board
- Design/build a mount (probably when I get my reprap working)
- Print a chocolate object!
As soon as I've printed something, I'll post some pics. Might be a little while as I'm trying to get an ABS extruder working first...