If you ever need metal working tools or pieces of aluminum, copper, brass, steel, or stainless, cut-to-size and shipped at reasonable prices, please check out: http://stores.ebay.com/Stoners-Tools-and-Raw-Materials?_rdc=1
He has hundreds of stock sizes and shapes in stock at his on-line store, or he will custom cut pieces to your size for only $.25 / cut. Paul Stoner is a super guy to deal with, easy to communicate with, and gets your parts shipped right out.
I have no connection to this company, other than being an enthusiastic customer. Please let him know you heard about him on Let's Make Robots!