I have seen an old movie about vehicles designed to operate in deep snow=20 that used that sort of drive. It was on top of a couple of long grain augers and appeared to be pretty=20 agile. On 10/22/2012 6:02 PM, John Gardner wrote: > If the blurb is accurate, rather small ornithopters > seem feasible. --=20 John Ferrell W8CCW =93During times of universal deceit, Telling the TRUTH becomes a revolutionary act=94 George Orwell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .