A simple way to Tri-cut the butt of a drill bit?

alvinj · 2013-04-27T04:33:12+00:00

Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2" drill bits that basically has no machinery? Draw filing, grinding whatever, don't care I mostly need a way to index 'em. :) What ideas you got popping out? xD Alvin in AZ

Apr 27, 2013 26 Replies

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alvinj 13 years ago

Cool. :)

I showed up right after they hauled the guy away. He was on a track welding gang that uses thermite to weld the rails together. A cable driven hand grinder's gas engine's governer went haywire and he was reaching over to kill it when the grinding wheel exploded. It broke both forearm bones and just about cut his hand off. :(

It was a brown resinoid wheel, ~16 grit ~8"x 1".

I've seen them track welders using 8"x 1/8" grinding discs and putting so much side pressure on 'em that the edge of the disc was ~3/4" out of line! 8-/ ...and they're just grinding away! LOL :)

There's a time limit. The dispatcher gives you the time between trains and you have to decide if you can get the job done in that much time.

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What's weird is the guy that got hurt was a brother to a buddy of mine in my-department and was going there just to meet 'im. :)

Alvin in AZ retired signlape

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Gunner Asch 13 years ago

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alvinj 13 years ago

Gunner Asch wrote:

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Oooo... I remember that. :) I was hanging out here when that happened. :)

We had to wait a day or two for the picture.

Alvin in AZ

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DoN. Nichols 13 years ago

Yes -- but since you will want to be flatting the whole length of the reduced shank, you will need to grip at the larger diameter, so the full set of collets -- at least 1" down to 1/2" -- I guess that you don't need the smaller ones.

There is MSC (or other vendors) -- but not as affordable as your "Kent's", likely.

[ ... ]

While I posted with two spellings -- one of which *may* be right. :-)

Enjoy, DoN.

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Wild_Bill 13 years ago

I've never tried it and wouldn't consider it a good practice, but.. using a small strip of silicon carbide wet-or-dry paper around a drill shank may improve the chuck's grip in a moment of desperation.

Cleaning any abrasive dust from the chuck afterward may prevent any detrimental effects. For an old, worn chuck, a smear of valve grinding paste on the drill shank may save the day, in a MacGyver emergency situation.

The SC paper gripping method works well in vises for gripping hard surface workpieces.

Shirley Someone has tried this one time.

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