There is a lot of information in this thread as well:
http://www.chiefdelphi.com/forums/sh...ad.php?t=47981
To reiterate, the first wheel will be printed on a rapid prototyping machine. The hub will remain as it comes from the machine for the time being, but will be used later to create a mold or cast for the finished product. We're not yet sure how that process will work. The rollers are being made into molds and cast in urethane.
The tab thickness is, I believe, 3/16". The wheel diameter is 2.5" and they're obviously not for FIRST use. Thus, they're mecanums precisely because they were meant to be mecanums. There are no prints for these wheels yet since, so far, we're working entirely with machines that can handle digital files.