Thursday, December 20, 2007

Turning Up The Heat

Figured out what was wrong with the heater. When it heated up, the electrical connections came loose. It'd get up to about 135C and start to cool down again. Nichrome doesn't solder well. I cobbled together half-assed crimp connections for it and, for good measure, wrapped the barrel in insulation.

This time, the temperature got up to 160C fairly quickly. I turned on the motor and let the filament feed in.

I'm not entirely sure what happened because the insulation blocked my view. Somehow, though, the heater barrel came out of the Teflon spacer. It doesn't look like the threads are stripped. There was a large blob of melted HDPE in the gap but none came out of the nozzle. I'm guessing the nozzle is clogged.

As it sits now, the extruder barrel is in pieces. The connections for the thermistor tore loose when the barrel came out.




Next steps:
1. Try to reposition the thermistor onto the barrel instead of the nozzle so that the nozzle can be easily removed for cleaning.
2. Remove the nozzle, heat it up and clean it out.
3. Reassemble and try again.

2 comments:

Zach Smith said...

hey, some quick suggestions:

1. use a hose clamp on the PTFE to keep the heater barrel in place better. you can get those at any hardware store.

2. i use a screw terminal for the heater connection. i think i specified an extra one in the parts list. anyway, solder the wires from the board to the pins on the screw terminal, then put the nichrome wires into the holes and screw them down. then ziptie the whole thing to the extruder itself. the nichrome may touch the plastic and melt it the first time you turn it on, but its okay.

RoundSparrow said...

I'm about 1 week behind you here, having many of the same problems ;) This whole thing is a learning experience for me, I'm far from a natural at this stuff.

// Stephen Gutknecht