So the graphite-resin-ethanol paint we requested a sample of eventually did come a while back. I’ve been playing with it, and it seems great for what it does. The alcohol doesn’t evaporate as nicely when trying to apply more than a thin film, however. Also, the resistance of a thin film isn’t quite as low as one might want for a conductor. I think a graphite and resin material could do quite nicely for resistors, though.
So, I was looking up what it might take to make just a resin and graphite compound myself. The third hit for “melting point of resin” on Google is the Wikipedia page for rosin. Not far down in the article, it’s mentioned that rosin is used as flux in solder. It now seems painfully obvious, but why not stick a strand of solder down the RepRap extruder head? It turns out that Rhys Jones did exactly that two years ago.
I’ll test out how well lead-free (mostly tin) solder adheres to ABS, but my hopes are pretty high for finally finding a good enough conductor to move along to the semiconduction. In other news, I’m still waiting on the Mendel we ordered in February, but I may be able to work with the DREAMS Laboratory before it comes. With their mechanical engineering experience with MakerBot 3D printers, they may be able to easily shoot down some of my likely impractical ideas, and suggest alternatives. Also, when the machine does come, I can probably use some help putting the thing together, so I’ll post on several mailing lists asking if anyone wants to join in the fun.
Forays Into Desktop Fabrication 