Excellent video! Very informative and great production.

metalworking. You had to resharpen drill bits a lot. Would carbide
tipped bits work? You also had to do a lot of filing. I use a carbide
rasp bit in my die grinder that might be good for roughing. E.g.:
http://www.ebay.com/itm/370998282545...em566138 8931
(that one is very expensive - I got mine years ago on eBay as a lot of
10 for about $1 each).

Bob