Darwin 1.0 Extruder - thermistor on a copper penny

So playing around I found a working (tested) solution for mounting my thermistor in a removable fashion that still got good readings. Inspired by Vik's blog reference to using a copper tab.. i couldn't find any thin copper tabs around

USA Penny 1981 and earlier are 95% copper
Canadian Penny 1996 and earlier are 98% copper

Of course you have to have a large drill bit that will make a hole just large enough to go over the end threads of the extruder barrel. I install the penny as tight as I can against my JB Weld before I then screw on my extruder tip. The extruder tip is making full contact with the penny, and if you do the hole in the penny just right, it is making good contact with the center rod.

I drill the hole offset to one side and then mount the thermistor on the side furthest from the hole.

Penny may warp or bend while drilling. I found it was best to do a stack of 4 pennies for drilling, they tend to absorb the heat better/etc. I used progressively larger drill bits.

// Oh yha, I think using a penny for metal purposes is illegal now in the USA, so I do not advise this.

Edited 2 time(s). Last edit at 01/03/2008 11:13PM by RoundSparrow.

very ingenious idea... i like it!