Small Drills

[Jim KParticipant @jimk]

Sharpening Small Drills on Grinder

[Jim KParticipant @jimk]

I have heard that it is possible to sharpen small drills on a grinder freehand, it was told to me by a friend who doesnt remember how he was told to do it. (by an old toolmaker)

What he remembers is that it was a very logical and simple way with no jigs or fancy set up.

Just wondering if anyone know of this technique.

[Frank DolmanParticipant @frankdolman72357]

    Old Toolmakers can do this.  Others can’t.

[John Stevenson 1Participant @johnstevenson1]

If it’s no jigs or fixtures then it’s just freehand with plenty of practice.

It can be done as it was done for years by the old hands.

One place I worked we made piano actions in wood and some of the pivot holes we had a 1 thou tolerance.

 

When i was told this I thought they were joking but no we had go and no go gauges to check these.  Add to that the drills were 0.0505 which don’t exist so we had to hand grind then from 0.0505″ drill blanks specially made for us, try them and stone them to the tolerance required all by hand.

 

Later they bought a Christian drill grinder which really helped.

 

I did learn a lot about small tool grinding from this experience and it’s held me in good stead as some of my current jobs require drilling nearly 3,000 2.5mm holes into some parts.

 

John S.

[Jeff DaymanParticipant @jeffdayman43397]

I do sharpen twist drills regularly by hand on an open wheel. I hold the drill at an upward angle same as the end grind (theoretically 59 degrees but I do this by eye) and start with the lip horizontal. I then roll the drill downward away from the lip in a sprial motion. After sharpening one one side I repeat for the other until the lips are same length (again by eye).

 

Your wheel must have a reasonably flat face, if it has deep grooves and rounded edges you will have a tough time.

 

It is an aquired knack but after practicing on 50 or 100 old drills it becomes natural. It would be a good idea to get some cheap old drills from a yard or car sale to practice on. My grandfather (master car and truck mechanic, self taught) used to give me a box of a few hundred dull ones to do, or some cold chisels, if I was asking him too many questions that day. If he used one afterward that wasn’t ground well, he would wake me up by throwing it over my shoulder onto the sheetmetal bench beside me. I learned fast. I don’t recall but I am sure it was him that taught me to do it in the first place, but it may have been my Dad or I may have just had a go one day. (It certainly wasn’t an old toolmaker that taught me)

 

For small drills some sort of magnifier device is essential.

 

I wouldn’t do it on a drill for a super high precision job, I would buy a fresh drill for that, but for everyday drilling for model work and home shop they are fine.  Cheers Jeff

[Jim KParticipant @jimk]

I agree Jeff the stone must be in god shape and the way you describe sounds to me like easy WITH PRACTICE.

When i originally heard the story i was thinking that the fute is rested on something and although i said freehand i wonder did he have something to give him a guide to certain angles. You know how these lads used things to make a job easier. like for example the thickness of a sixpence to give a certain height.

JimK

[Eric CoxParticipant @ericcox50497]

Have a look at these two web sites.

 

http://www.ehow.co.uk/video_4418688_sharpening-drill-bit.html?cr=1 

 

http://www.clag.org.uk/drills.html 

[CirclipParticipant @circlip]

”  the stone must be in god shape   “

 

  Hopeing for “Divine” intervention Jim?????

 

  Sorry, couldn’t resist.

 

  Regards  Ian.

[Jim KParticipant @jimk]

I am blaming the keyboard and vista for that

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