As previously mentioned, Kapton is a candidate material for a conveyor belt build platform. I did a small test with a Kapton belt and heated build platform. The results are promising.
The image below shows the mechanism I’m using for testing. Two steel shafts are held apart by an acetal structure. Acetal is used directly rather than acetal bushings in wood. The platform snaps directly to the CupCake y-stage like the regular build platform. A kapton belt made from Kapton tape is looped around the shafts. Two Kapton layers were placed together with the sticky sides facing each other. The design files are available in subversion.
I would appreciate any ideas from the community in the comments below.
EDIT 2010-03-17-0626: So far I’ve only tested with what you see in the video, a mall thin ABS exrusion. The kapton does not seem to expand when heated. It’s also not very elastic, so I’m considering adding tension springs to hold down the tension bar. Right now the bar is just screwed down to keep the belt flat. I’ll plan on testing with a belt made from wide kapton film rather than a bunch of tape. I’ll also be testing to see how large of an object can be printed with this method.
EDIT 2010-03-17-1435: The springs I have in mind would sit between the tensioning rod and the screws that push the rod down. I’d want this so a fairly constant force is exerted on the belt if it were to expand when heated. Below is a side-view drawing of the conveyor mechanism.