Wednesday, December 26, 2007


This is the current sate of the extruder. It has:
- sandpaper to keep the PTFE barrel from slipping
- a hose clamp to keep the heater barrel from slipping
- a terminal block glued to the hose clamp to connect to the nichrome wire
- PTFE tape wrapped around the heater
- a thermistor cannibalized from a thermometer, embedded in JB Weld and strapped to the barrel

And, yes, "it's alive". Well, pretty much. It doesn't fall apart, melt or catch fire, which is a big step up.

Funny thing, though: The firmware is being difficult. The old firmware (v1.0) runs the heater properly but flakes out on the temperature readings. The new firmware (20071219) seems to do better at temperature readings but flakes out on heater control over about 80C.

I wonder if there's some sort of interplay between the RC factor of the thermistor input and the duty cycle of the heater output.

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