I put this on another post, but it might be of interest to all (or some)
Build your own beam table
Undrilled 6061 1/2" flat aluminum plates are available here for reasonable prices.
(I've bought from them many times and their shipping is FAST
http://www1.mscdirect.com/CGI/NNPDFF...00&PMPAGE=9000
page 1732 on the bottom