Sharpening drills

[Colin Jacobs 1Participant @colinjacobs1]

Just wanted to say how a friendly lot you all are, just been to Great Yarmouth to see an ME who sharpened all my drills. and showed me how to make a jig.

 

Thanks mate

[Colin Jacobs 1Participant @colinjacobs1]

Thankyou mate

[WALLACEParticipant @wallace]

Couldn’t have been a CNC drill sharpener then . . .

 

W.

 

 

[Colin Jacobs 1Participant @colinjacobs1]

sorry don,t get the joke

[Speedy Builder5Participant @speedybuilder5]

Been readin Model Engineer dated 1950 something.

 

The writer claimed he could sharpen a drill to make a hole as accurate as a reamer and had been doing this for a number of years. His secret was to sharpen as normal, then grind off the very tips of the outer edges of the cutting edges . It looked as though the cutting angle was a normal 118 deg and then the outer corner of the lip (.020 – .040) ground to about 45 deg.

[DustyParticipant @dusty]

I have used this method or a slight variation of it for years. my method is to stone a small rad on the lip of the drill. To be accurate these rad’s should be of the same size otherwise the drill will only cut on one side and tend to cut oversize. The other thing is you need to leave only a few thou to take out with this drill, much the same as a reamer. The finish that you get in the hole, provided you feed slowly is generally better than a reamer. The other problem is that if the original hole is not round or off line then the drill will follow it. It is a trick worth knowing, have a little practice on something that does not matter until you are confident in your ability before you use it in anger.

[David Clark 13Participant @davidclark13]

Hi There

This method works well.

You probably won’t get the drill in the hole if you try it by hand afterwards.

regards David

 

[WALLACEParticipant @wallace]

Hello Colin – the joke being that the the recent thread about CNC in MEW wasn’t what I would call ‘friendly’ !!

 

 

 

W.

Edited By WALLACE on 07/06/2011 19:06:40

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