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This may not be the place to post this but a question for you manufacturing guys. How do you sharpen your drill bits. I have some large size bits that have become unusable and pretty high dollar pieces as well as some that belong to my dad and probably over a 100 years old. These machines like drill doctor etc. will not handle large bits so what do you guys do. Be interesting to hear all the suggestions.
 

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I've not gotten good at it yet but a guy I work with can take a bit to a Bench grinder and come back with a better bit than new.
 

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I sharpen by hand on a bench grinder. It's as much an art as it is a science, I used to work with a guy that had basically mastered it. He tried to show me, but I just never picked it up that well. I'm sure someone here can describe it better than I can, but you want the bit to slope away from the center and also down from front to back. If you decide to try it, make sure your bench grinder tool rests are adjusted up properly.
 

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You can use a bench grinder or a belt sander to do the primary and secondary relief. Quench in water after every touch. You can web thin on a bench grinder if you have a sharp corner at the side of the wheel but you may not need to because you should be starting your holes with smaller drills anyway. Even if your angles aren't perfect you should be able to get it to cut. In my business though we have to be even enough to have the drill produce a hole within a couple thousands of its diameter. Uneven geometry tends to cut oversized.
 

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I sharpen by hand on a bench grinder. It's as much an art as it is a science, I used to work with a guy that had basically mastered it. He tried to show me, but I just never picked it up that well. I'm sure someone here can describe it better than I can, but you want the bit to slope away from the center and also down from front to back. If you decide to try it, make sure your bench grinder tool rests are adjusted up properly.
this is how my neighbor did it also. he couldgrind on a bench grinder, and man the shaving's flew. he tried and tried-:banghead: but i could never master it. so my wife bought me a drill Dr. one yr for christmas. :yahoo:boy i was excited-just like a kid. took it down to garage-read all the directions--put it together, and jeez whiz-disaster. i wanted to throw it at the wall-:nunu:but i new better. so one of our hunting buddy sat me down, did something to it, and perceded to sharpen bits. i still don't know what he adjusted:banghead: he wouldn't tell me:unknown:so it has sat in the cupboard for yrs now. someday this summer-i might grow up-and try it again:lolol:
 

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I've used a bench grinder and drill dr. I do better with the grinder. I've got a buddy who can get the dr. To make them better than new.

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

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I have a Drill Doctor, use it up to 1/2" bits, you can get a kit to make it sharpen up to 3/4" bits on my model.
It shines between 3/16" to 1/2" bits, but kind of tricky on 1/8" I find.
Never did get the 3/4 kit, I use my bench grinder for that and bigger, as Blake said, that's a mixture of art and science.

Sometimes I do an acceptable job, sometimes not so much with the bench grinder.
Takes practice getting the right pressure, angle and twisting action follow thru.
I like to have a good bit sitting there same size as the one I'm trying to sharpen.
A visual guide like that kind of helps you from straying too far from factory bit geometry.

Also have a pan of water there and quench, quench, quench.
 

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My neighbors FIL showed me how a few years back. I wish that old guy was around everyday - same as what you guys described - bench grinder, guided by hand, and better than new.

I've tried since he showed me, and sometimes I win, sometimes not. I remember him showing me that the corner where the angle meets the outer wall of the "cylinder" of the bit as the most important. Using the flat sidewall of the grinding wheel was an important tip to ensure that the cutting edge is wider than the cylindrical part. That angle MUST be the widest part of the bit.

I think this is the biggest, most important, quote from above:

should be able to get it to cut
Drill bits should CUT - there should be coil-ee shavings. Cutting fluid is important, and RPM is VERY important. I just bought myself a drill press that goes as slow as 180RPM for big bits (>1") in stainless. When you have the parameters right, drilling is easy and quality bits will last for a good long while. When you try and ream a 3/4" hole at 2500RPM with smoke and squealing, it's not easy and it's not fun.
 

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I got pretty darn good at sharpening split point bits at work. I never did anything smaller than 3/8. Small ones were more difficult, plus not cost effective for my time to deal with them. Normally I always did the more expensive larger sizes. The bench grinder was OK, but I could never count on a nice dressed wheel. I much preferred the belt sander, and it always gave me excellent results.
 

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I got pretty darn good at sharpening split point bits at work. I never did anything smaller than 3/8. Small ones were more difficult, plus not cost effective for my time to deal with them. Normally I always did the more expensive larger sizes. The bench grinder was OK, but I could never count on a nice dressed wheel. I much preferred the belt sander, and it always gave me excellent results.
Never did try a belt sander, what grit do you use?
 

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Almost a lost art. I have a drillDr but never can get it to work. I have seen community colleges that offer weekend classes on how to use the drill dr.
Have a friend who can do all that stuff. Runs a bridgegport mill like its a TV remote. Now a days just place some metal in a cnc and it finds the center, edges, off it goes...
 

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I do them freehand on a bench grinder with a white wheel for tool steel. I keep a cup of water nearby and constantly dip to keep the tip cool. For drilling copper or brass, I blunt the bits. Same for my metal lathe. I buy blanks and grind them.
 

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Never did try a belt sander, what grit do you use?
They were pretty coarse. 40 or 60 grit, but I should have mentioned that I had a "worn out" one I kept just for doing bits.
 

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I've used a bench grinder and drill dr. I do better with the grinder. I've got a buddy who can get the dr. To make them better than new.

Sent from my SAMSUNG-SM-G870A using Tapatalk
My experience exactly with the DD. I have a gage by the grinder that I double check with once in a while.
 

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I've sharpened by hand everything from an 1/8" all the way up to a 3" drill bit on a grinder. i don't know how best to explain the process though. It seems to be one of those things that once you get it you just know how to do it like you always have known. It's kind of like teaching someone to roller-skate - you can give them the description but you can't impart the experience...

Here is a pretty good reference site for how to sharpen a drill. The pictures are helpful!
http://www.michigandrill.com/tech/twist_drills/point_grinding.php

A few tips that I can give you to help you be successful:
  1. The larger the bit the easier to grind - you simply have more room to work.
  2. The grinding wheel makes a huge difference - a fine grit wheel produces better results when you only have touch-ups to do. A broken bit can use a more aggressive wheel but you should finish on the finer wheel.
  3. Do not heat the drill bit up, it will loose its temper and not last as long. Small grinds and keep it cool with water. If the tip hints at glowing the least bit red you are being too aggressive.
  4. Keep the point symmetrical or it will wander or drill oversize. It can also dull faster as one side will cut more than the other (This is by far the hardest part)
  5. The angle of the grind (center to cutting edge) is important based on what you are drilling. Lexan and plexi like to have a shallow angle, almost flat. Steel and general drilling is 89-120 deg.
  6. Having a clean square corner on the grinding wheel makes a huge difference. If you have a 1/4" radius on the edge of your wheel you shouldn't try to sharpen it there. Getting into the web and providing behind the "blade" relief will be hard to do.
One of these can be very helpful in getting your symmetry right (there are cheaper ones out there - some less than $20:
https://www.amazon.com/Starrett-22C-degree-Graduations-Length/dp/B0006J4CT0

When my dad was still alive I would go to his auto body garage a few times a year to hang out. Invariably there would be a handful of broken drill bits laying on the bench. He never had a good grinder or wheel, but I could always manage to get some more life out of the bits. Once you get the skill you can be less fussy with the wheel/grit. Trying to learn I would get a fine grit wheel that will keep you from getting too much grinding done. That is how you keep the side even. You can chase a point down both flutes for a loooooong time trying to get it even with an aggressive wheel.
 

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this is how my neighbor did it also. he couldgrind on a bench grinder, and man the shaving's flew. he tried and tried-:banghead: but i could never master it. so my wife bought me a drill Dr. one yr for christmas. :yahoo:boy i was excited-just like a kid. took it down to garage-read all the directions--put it together, and jeez whiz-disaster. i wanted to throw it at the wall-:nunu:but i new better. so one of our hunting buddy sat me down, did something to it, and perceded to sharpen bits. i still don't know what he adjusted:banghead: he wouldn't tell me:unknown:so it has sat in the cupboard for yrs now. someday this summer-i might grow up-and try it again:lolol:
Lots of good vids on the Internet about how to use the Drill Doctor, some put out by Drill Doctor covering every model they
make.
I have the X500, I like the results from a 3/16" to a 1/2" bit.

Slick and quick once you get the hang of it.
 

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I use my bench grinder. I was taught in the early '60s by an older service tech at my families AG dealership. I guess I was about 11 or 12 years old.


In the '70s, our shop purchased a electric drill bit sharpener. That thing could really screw-up a bit. :banghead: When I worked as a road service Tech, I'd use my 4.5" side grinder, but it was tricky, and dangerous.

I'm sure the bit sharpeners of today are designed and built better than back in the '70s, but I'll stick to my bench grinder.
 

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Drill Dr. works very well-if you take the time to read & follow the instructions, which means you will need about an hour's time on average to go from instructions to sharpening. I have a Drill Dr. that sharpens up to 1/2" which for most of us covers it all. Drill Dr. is made by Darex which makes drill sharpening equipment for the professional machinist-tool & die maker, etc. which costs in the thousands for a shop to buy. Don't want to sound like an ad for them. But it works well if you learn.

Sharpening a bit at the grinder is an art & skill that will take you more than the hour I mentioned above. There are not too many machinists left out there than can do it. Today most just throw away a worn bit. My dad was a professional tool & die maker & he could take the worst chipped or broken bit over to the grinder & turn it into a bit better than new. A lot of these skills have been lost. Today, no one serves an apprenticeship or as a journeyman where things like sharpening a bit or hand scraping machine tool beds or filing by hand a piece of steel to the thousandth of an inch was a requirement to earn the title of Professional or Master Craftsman.

No longer any pride-no longer any glory.
 

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Discussion Starter #19
I knew I could get some good advice and it looks like I did. I appreciate all the replies now to just put some of them to work. It seems the larger bits are the ones I mess up so and the most expensive to replace. I have used the bench grinder and can do some pretty good but I sure mess up a bunch to boot. My dad use to use one of those old grind wheels like farmers use to sharpen an axe on and he could really put an edge on one. But like most kids I did not have enough interest to really figure out how. That is my first project in the morning. I am trying to redo some garden tools and need several holes drilled.

Thanks to all of you who replied. I guess I just need some practice.
 

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I have a power down feed drill press, so my drill bits almost never get dull.

So, if you use proper drilling technique, the drill bits stay sharp.
Rather than worrying about how to sharpen,, I simply buy new drill bits, and toss the dull ones.

If you do not drill properly, be happy with Drill Dr sharpening, the bit will dull quickly anyways.

With a power feed drill press,, over 1,000 holes in 1/2" thick steel per drill bit is not a challenge.



:good2:
 
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