I was actually surprised with the results. I'd never tried this before and definitely learned a few things. I plugged 2 of the holes with clay before making the mold so that I could remove the part from the mold after the silicone rubber set. I pushed the clay in far enough so that it would make an impression (which would help with the drilling after the cast was finished). One of these has been drilled out - the other hasn't yet.
Nice. In a group in the Netherlands we've casted several Darwins (these are not even all of them):
ReplyDeletehttp://picasaweb.google.com/erikdebruijn1/RepRapDev#5428412352396040370
Once you have the moulds, it's pretty fast. You do need a vacuum pot to get it without air bubbles, though. So you need a gasket, tick piece of acrylic/glass, a pot and a pump.
B.t.w. did you do the survey yet? http://www.reprapsurvey.org/
Thanks! (and sorry for spamming your blog, but it's important for improving RepRap's innovation process)