Posted by Sherman in Idaho [24.32.202.166] on Friday, September 20, 2013 at 01:20:38 :
In Reply to: Drill shaping gig posted by Perry [96.242.137.67] on Thursday, September 19, 2013 at 21:29:50 :
There are all different kinds of drill sharpening jigs. A self-contained unit like the "drill doctor" is popular these days. Before that the popular cheap one was a deal that you mount on the bench next to your bench grinder that would hold the right angle. Larger bits can be done tolerably well free-hand, with practice. Smaller ones are next to impossible to do by hand while maintaining any sort of correct centering.
I have a nice Grizzly knife grinder (no longer in production) that I got for sharpening planer knives, that includes a drill sharpening jig. It works very well, maintains a correct center, and automatically provides the right relief. You can set the angle to whatever you want and you can drip coolant if need be to avoid burning the temper out of the steel. Does not do split points, though. I think the general practice is to discard rather than sharpen bits under 1/8".