--Hiya; chiming in a little late here, but to see a good
implementation of what you want to build you might head over to
battlebots.com and check out a heavyweight called The Judge. Before it was
dismembered by a spinbot it had a spiked arm on it that could punch holes in
1/4" steel plate. Heh.

--
"Steamboat Ed" Haas : "Hold on! we're passing
Hacking the Trailing Edge! : through the moronosphere!"
www.nmpproducts.com
---Decks a-wash in a sea of words---