Sharpening drill bits by hand

[ajl6549]

Thats a very "in depth" discription of how to hand grind a drill! but remember PRACTICE PRACTICE PRACTICE PRACTICE!!!

[sdantonio]

Originally Posted by widgitmaster Most bench or pedistal grinders do not have wheels with keen sharp corners, the kind needed to do a nice split point! Eric

Hi Eric,

A buddy of mine made up a wheel once that has corners as sharp as you want them and it works suprisingly well for small delicate tools. Take a circular piece of particle board about 6 inches, attach it to a motor running at a reasonable speed (I'll leave it to you to decide what a reasonable speed is), true it up with a rasp and file, then, right before sharpening anything hit it with a bit of course sharpening compound (stick form works best).

You can actually make several and go right through the different grits. In his case, after this wheel he jumps right to a felt wheel.

One trick is to reverse the motor so that the wheel is spinning up (from the point of view of the person sharpening), that way youir not going to catch the wheel with a sharp edge and get your hands pulled into it or send the tool flying end over end.

[The Puma Man]

Just let me say, this is all bull+++t really. I've been a machinist for some 35 years and if a close tolerance is required you just can't rely on hand grinding, it's just not reliable. For open tolerance (0.3 mm) then yes maybe. Close tolerance work drill grinder every time

[tobyaxis]

Originally Posted by The Puma Man Just let me say, this is all bull+++t really. I've been a machinist for some 35 years and if a close tolerance is required you just can't rely on hand grinding, it's just not reliable. For open tolerance (0.3 mm) then yes maybe. Close tolerance work drill grinder every time

For that type of close tolerance work I use Seco Carboloy Solid Carbide Drills. TiN Coated 140 deg. Split Point for exotics and 135 split point for softer materials other than Aluminum. 118 spit point for Aluminum 2,6, and 7000 series. The drill finish is like a reamer finish and you can hold .0005 on the diameter all day with the right machining conditions feeds and speeds.

No hand grinding for these drills.

[Geof]

Originally Posted by The Puma Man Just let me say, this is all bull+++t really. I've been a machinist for some 35 years and if a close tolerance is required you just can't rely on hand grinding, it's just not reliable. For open tolerance (0.3 mm) then yes maybe. Close tolerance work drill grinder every time

Perhaps in the hands of some people a drill cannot be sharpened to cut within about 0.002" of size but it can be done. And when you are talking drilled holes with standard HSS bits anyone who thinks they are reliably getting much better than that even with a new drill is dreaming.

Yes it takes time and a drill grinder is faster but it is possible; I was doing it about 44 years ago.

[widgitmaster]

Originally Posted by Geof Perhaps in the hands of some people a drill cannot be sharpened to cut within about 0.002" of size but it can be done. And when you are talking drilled holes with standard HSS bits anyone who thinks they are reliably getting much better than that even with a new drill is dreaming. Yes it takes time and a drill grinder is faster but it is possible; I was doing it about 44 years ago.

Too bad you didn't work with me, I have sharpened .040 cobalt drills using a long slender stone under a microscope all day long, as they were getting .0002 tollerance in each 304-SS part the CNC's were drilling!

I have stoned a slight radius on the outer points of hand sharpened drills and made them actually cut undersize!

For twenty years, I wore an eye-loupe clipped on to my egeglass frame, as everyone would constantly ask me to sharpen their tools! Having a nice set of diamond plated files, and assorted stones in my toolbox, was a necessity in the places I'v worked!

The hardest thing to sharpen is those damn one lip carbide engraving tools, as one slip and the point is toast!

Eric

[The Puma Man]

Originally Posted by Geof Perhaps in the hands of some people a drill cannot be sharpened to cut within about 0.002" of size but it can be done. And when you are talking drilled holes with standard HSS bits anyone who thinks they are reliably getting much better than that even with a new drill is dreaming. Yes it takes time and a drill grinder is faster but it is possible; I was doing it about 44 years ago.

So Geoff, you think you’re so clever. I can sharpen a drill in less than a minute using our drill grinders, unless it’s a big drill bit say 40 mm dia. and above, which takes possibly 2 minutes. Now I’m talking about repeatability and very quick turn around because in the airbus industry of which I work we cannot afford to have one, scrap, and two, unreliability and if you say you can grind 100 drills in say 2 hours’ by hand and they all cut size FIRST TIME, well I’ m thinking you must be Clark Kent

[Geof]

Originally Posted by The Puma Man So Geoff, you think you’re so clever....

Nope, check: http://www.cnczone.com/forums/showth...6&page=5&pp=15

[tobyaxis]

Originally posted by The Puma Man (quoting didn't work)

So Geoff, you think you’re so clever. I can sharpen a drill in less than a minute using our drill grinders, unless it’s a big drill bit say 40 mm dia. and above, which takes possibly 2 minutes. Now I’m talking about repeatability and very quick turn around because in the airbus industry of which I work we cannot afford to have one, scrap, and two, unreliability and if you say you can grind 100 drills in say 2 hours’ by hand and they all cut size FIRST TIME, well I’ m thinking you must be Clark Kent
--------------------------------------------------------------------------

Originally Posted by Geof Nope, check: http://www.cnczone.com/forums/showth...6&page=5&pp=15

Geof is clever, wise, and cool

I am Honored to be able to visit a place with members like him, Widgitmaster (Eric), LakeSide (Mike M), Tjones, Gandalf (Wolfgang), MetLHead (Scott), Ger21, Huflungdung, GenGuy, CarbideCraters, Miljnor and so many others. I've made a lot of good friends here.

We come here to Help and be Helped, not to Knock eachother.

And if I sound corny.......GOOD!!!!!!!

Pumaman,

Take it easy Dude!!!!!!!! This isn't a compitition!!!!!!!!

[widgitmaster]

Thanks tobyaxis!

I Agree, the reason for this poll is to inform others, not to compete or compair!
This fourm is superior in every way, and I will continue to share ideas, knowledge, and my experiences with others freely!

In the past I have worked in shops where I felt a dumb as a box of rocks, and in other shops I felt superior and under paid! Everyone's knowledge level and skills are at different strengths, and it has been my experience that anyone can learn if the desire is present in both the apprentice and mentor! A good example was the massive factories during the wars, where everyday women were doing amazing jobs on machines and in foundries while their men were getting killed on the front lines!

Well, the war is over, and we are now at peace !

[ozzie34231]

I see this thread is a bit old, but here goes.

My dad, a toolmaker, taught me to sharpen drills by hand about 50 years ago and it has served me well. I mostly use a drill doctor now but there are problems with it, like setting the original holding position as different web sizes produce vastly different results.
Anyway I'm not interested in discussing Drill Doctor, but I am wondering if there are plans out there for a good quality, home built drill grinder. I'm a hobbiest machinist, so time is plentiful, money to buy a used grinder is not. (shipping et al)

The cheapies, like Sears, seem to use the right principals, but lack any kind of weight or solidness. Would it make sense to use the geometries of those units to build a sturdy unit? But then they won't narrow, will they?

Small bits are really cheap so there's no need for tiny sizes, but I might like to sharpen a 1-1/4" rather than pitch it.

Thanks,
Jerry

[The Puma Man]

My apologies Geoff I thought you were knocking me in the answer you posted to me!!