Found this video by a machinist very well done. He uses the plain aluminum oxide wheels too. I practiced on some old B&D HSS bits made in Germany and they cut like new now.
Hand-Sharpening Twist Drills Video
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MolaKule
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The problem I have is making sure the correct angle is cut, since I don't have an angle guide.
been doing it this way for many years. Just don't get too aggressive and put the edge back on.
When I took my A&P practical exam a long, long time ago I had to demonstrate that I could hand sharpen a twist drill.
It takes a little practice but it's not difficult.
Today most people toss a drill bit if it starts to get dull. They do the same with lots of other stuff as well.
It takes a little practice but it's not difficult.
Today most people toss a drill bit if it starts to get dull. They do the same with lots of other stuff as well.
I took a machine shop class in college years ago. This was one of the first lessons. That and making our own lathe bits.
Originally Posted By: MolaKule
The problem I have is making sure the correct angle is cut, since I don't have an angle guide.
Two hex nuts butted up on the flats will give you a pretty good angle gauge to check against for most drills at 120 degrees. Other than that you get the cutting edge lengths even and make sure you have some relief behind the cutting edges and you've got a serviceable bit again.
The problem I have is making sure the correct angle is cut, since I don't have an angle guide.
Two hex nuts butted up on the flats will give you a pretty good angle gauge to check against for most drills at 120 degrees. Other than that you get the cutting edge lengths even and make sure you have some relief behind the cutting edges and you've got a serviceable bit again.
One problem I've had when I got started, and seen keep others from hand sharpening, is their grinding wheels are not round. Bouncing the bit around is not conducive to getting a good grind.
Simply buying a diamond dresser (flat, not point) and getting it flat and round is the first step towards a good drill bit.
Oddly enough, I learned how to hand sharpen drill bits from getting a Drill Doctor 500. Broken bits needed to be close to normal geometry before the DD500 would sharpen them, and I found I could get them really close by hand. What I haven't learned to do by hand is do a split point, something the DD does well.
It's amazing how much grief us DD owners get from some old-school types. On another forum, one guy posted a very long diatribe about getting a negative relief angle and how the DD was useless and would never replace hand sharpening. Too bad he didn't read the extended instructions on how to deal with tight twist drill bits.
And oh yeah, they're not cumbersome and tiresome to use, or cost a ton of money. For one thing I don't need a rule or protractor.
I got mine on closeout when the X models came out, and it's more than paid for itself. I'm a special case, though, I inherited several hundred drill bits, many dull, but all good old US made bits.
Simply buying a diamond dresser (flat, not point) and getting it flat and round is the first step towards a good drill bit.
Oddly enough, I learned how to hand sharpen drill bits from getting a Drill Doctor 500. Broken bits needed to be close to normal geometry before the DD500 would sharpen them, and I found I could get them really close by hand. What I haven't learned to do by hand is do a split point, something the DD does well.
It's amazing how much grief us DD owners get from some old-school types. On another forum, one guy posted a very long diatribe about getting a negative relief angle and how the DD was useless and would never replace hand sharpening. Too bad he didn't read the extended instructions on how to deal with tight twist drill bits.
And oh yeah, they're not cumbersome and tiresome to use, or cost a ton of money. For one thing I don't need a rule or protractor.
Agreed. I bought a flat, diamond wheel dresser long ago to keep my wheels in shape. They sure work better that way!
Never used a DD, but have heard of them.
I helped a neighor with some truck painting, he was just splotching it on there...even removed the spray head from the rattle can (
). Just clueless...so I laid down a few even strokes, but he soon went back to his way!!!
He just didn't get it. I guess many don't, and thus don't have the patience nor control to sharpen bits by hand or do other fine, meticulous hand work.
I do take it for granted now, but I spent years and years training myself, gaining patience and wanting to increasingly elevate my skills to a higher and higher level.
Never used a DD, but have heard of them.
I helped a neighor with some truck painting, he was just splotching it on there...even removed the spray head from the rattle can (
He just didn't get it. I guess many don't, and thus don't have the patience nor control to sharpen bits by hand or do other fine, meticulous hand work.
I do take it for granted now, but I spent years and years training myself, gaining patience and wanting to increasingly elevate my skills to a higher and higher level.
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