Author Topic: Sharpening tiny drills  (Read 7383 times)

Offline mklotz

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Sharpening tiny drills
« on: January 03, 2010, 11:44:21 AM »
The best way to sharpen small drills is to buy them by the dozen and discard the dull and broken ones.

Nevertheless, there's always the inevitable late Saturday shop session where you break your only #64 drill and you're dead in the water until you can order a new one on Monday.
Then it's nice to have a way to touch up a buggered drill.

Here's an approach I use on those rare occasions.  Its operation depends on the fact that, for very small drills, there is no need to try to make a conical point as found on larger drills.  Simple flat facets that create the cutting edges are all that is needed.  (In some senses, this jig embodies the same principle that gemstone diamond faceters use, albeit with only a single faceting angle.)

The device consists of a small pin vise fitted into a piece of aluminum angle.



The pin vise is free to rotate about its axis and, when properly oriented, can be locked in place with the small black plastic finger knob where the arms of the L meet.  After mounting the drill in the pin vise collet, the pin vise is rotated to align the drill web with the line where the two arms of the L meet.

Then it's a simple matter of turning the assembly over and stroking the drill along a grinding stone as shown in the following photo...



The top of the angle should be horizontal so a spacer the same height as the grind stone is used.  (At my desk, my calculator was handy.  In the shop, a block of aluminum is used.)

Now to create the matching facet on the other side of the drill tip, it's a simple matter of flipping the fixture over and repeating the operation...



Inspect the tip with a loupe.  If the facets aren't quite equal, a quick swipe or two will fix it.  Since the drill to stone angles are preserved by the jig, you won't have multiple facets.

Credit where credit is due...

This jig was made by and given to me by Norm Wells, the most prolific tool maker in our local metalworking club, SCHSM (see my sig for its URL).  I'm not certain if the design is Norm's.  I seem to remember seeing something similar in a magazine but I could be remembering diamond faceting tools - a mind is a terrible thing to lose.
Regards, Marv

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Offline chuck foster

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Re: Sharpening tiny drills
« Reply #1 on: January 03, 2010, 12:06:59 PM »
thanks for this great idea marv.  :thumbup:
i will be making one of those jig's very soon.  :dremel:

chuck  :wave:
hitting and missing all the way :)

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Offline Jere

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Re: Sharpening tiny drills
« Reply #2 on: January 03, 2010, 03:35:20 PM »
Looks like a good idea, I will need to try making a version of yours as well.

John Wilding describes a "wishbone" jig in his book "Tools for the Clockmaker and Repairer."  It is a commercially made jig (at least at one time it was), and I have been on the lookout for such a tool.  For now I've been using the "buy in bulk" method...

Jere


"If only I had known, I should have become a watchmaker."  A. Einstein

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