PDA

View Full Version : drill doctor



h.w.evers
06-09-2001, 03:21 PM
I recently obtained a Drill Doctor and seem to be getting the hang of it, however, the "chisel edge angle" seems to be larger than the 125 to 135 degrees recommended by other sharpening jigs, such as Sears, General, etc..
Does this matter at all? Has anyone else run into this? Suggestions? Comments? Thanks!
Howard Evers

AJE
07-17-2001, 09:32 AM
The chisel edge angle is a conseqence of the drill point angle ( cone apex angle) and the rate of change of the backing off angle behind the cutting edge.

A correct chisel edge angle suggests the other two parameters are correct.

Commonly, drill point grinding jigs users get he wrong backing off if the drill point extends too far out from the jig.