Jeremiah Zukaholic Posts: 2,666 Joined: May 30, 2006 Logged Objectives (in order of priority):* Protection of critical components* Slide well* Light as possible* On a student budget (made with tools I have, or can cheaply acquire)Steel is heavy, and aluminum is too expensive, and I don't the tools to cut, drill, or weld with. Enter: UHMW & HDPE (cutting board plastics). They're light, slide better than metal, absorb impact better, can be cut / drilled with wood-working tools, are quiet when scraping, and readily available. UHMW is stronger, but costs x2 more than HDPE. 1/2" x 24" x 48" sheet is about $100 UHMW, or $50 in HDPE.I've read of people using both materials, but most favor UHMW for it's superior strength. That said, HDPE still gets favorable reviews from the few daring enough to try it first. Minimum recommendation is 3/8", most opt for 1/2", and the more hard-core go with 3/4" or 1". I think 1/2" is minimal if you counter-sync your screws / bolts (to protect them from rock rash, and shearing).