Original poster: "John Richardson" <jprich-at-up-dot-net> Hi Gerry, A piece about 5/16 long and half of the diameter (5/32) of the flying electrode. Put a nice mark in the plywood box. > Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> > > Hi John, > > What part of the propeller gap broke? > > Gerry R >