# SHARPENING DRILL BITS.



## John J (Dec 29, 2007)

I started this post so I would not l HI Jack the one on Keyless Chucks.

How do you sharpen your Drill bits?

I use the sooper Dooper Deluxe Drill Doctor. 

It works well but sometines not on the real small ones.

JJ


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## dieseldude (Apr 21, 2009)

John- I also use the super (sooper) duper (dooper) deluxe Drill Doctor. It really does do a great job on most bits. I don't sharpen the tiny ones because I usually break them and swear at them first!!! He he he he!!!


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## Dan Pantages (Jan 2, 2008)

I do not believe you can beat a Drill Doctor. I have the 750 which does up to 3/4" and down to 3/16, past the ends of these sizes I don`t think it`s important. Personally I don`t think there is a better tool made for sharpening drills, just my opinion.


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## Totalwrecker (Feb 26, 2009)

#60 - 70 (as well as fractional) bits can be sharpened on the side of a 'fine stone' seperating disc. Medium speed. Slower as the size decreases. It's hand held and done by sight. a slight twist as you hold it against a spinning disc. Always wear eye protection, I wear my optivisors to see what I'm trying to do. Cut into the edge, never away. Pin vises save the fingers. 
Not all seperating discs are the same, I have some that are .009" thick, these are too fragile for sharpening, but the ones aprox .020 are good. Not the ones from Dremel, they are too coarse (ones I've seen). 

John


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## RailCat (Apr 10, 2009)

Just looked at the Drill Doctor web site and the YouTube video link I found there. For the price, it looks like it may work very well for a hobbyist. I have had a Black Diamond BW-95PC at the shop for 10-15 years now. It works well 'though I need to disassemble the point splitting arm and clean it. It still has the same CBN wheel it was purchased with. The biggest advantages I see over the Drill Doctor are that it can sharpen parabolic flute drills, has an interchangeable collet holding system that grips the drill close to the tip, and probably has more adjustments. It can sharpen a point angle down to about 80 degrees. (We use 90 degree points for spot drills.  Common point angles are 118 degrees or 135 degrees.) It can also do brass points to prevent the drill from sucking in on softer metals. Its only drawback I can see is its price. I was shocked when I Googled Black Diamond's site and saw the prices. I cannot remember how much we paid for ours. I see the Drill Doctor has adjustments for material removal and point angle. I wonder if there is an adjustment for heel clearance. This usually needs to be changed depending on the point angle and web thickness. 

Scott


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## hawkfanjohn (Nov 17, 2009)

I had a guy we got from temp services ask if he should sharpen some bits after we broke a couple at a secluded job site. Found out his previous job was to hand sharpen bits (constantly) ! After watching him I started sharpening my bits on a grinding wheel by sight. While I'm not anywhere near what that guy did I get about 75-80% a lot sharper than they were! 

never tried one of those fancy sharpening machines


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## Madman (Jan 5, 2008)

I had the Drill Doctor 750 at one time. I never had good luck with it, other than occasionally I would get good results. Before the Drill Doctor, I had one of these http://www.amazon.com/AJ-Drill-Bit-...amp;sr=1-6 I sold my D.D. and went back to the General drill bit sharpener. In my opinion, it can't be beat. Everything is right there in the open for you to see. Instructions are simple, even* I* got it.


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## Jack - Freshwater Models (Feb 17, 2008)

Good drill sharpening jig/fixtures are expensive costing hundreds of dollars or more. Typically, a machine shop will spend about $1800 on a drill grinding machine. Not exactly something for the home work shop. 

General makes a simple drill sharpening fixture available in many hardware stores for about $20. It's OK but doesn't work like a pro unit. If you add some sort of screw feed arrangement to the base they work pretty good for many medium sized drills in the 3/32" - 5/16" range. 

I'm not imprerssed with stuff like the DD as they do not generate the proper geometry. On any cutting tool proper geometry makes all the difference. 

Drills aren't meant to make precision holes which is done by various types of reamers. Very small drills are usually sharpened by hand at the factory by people who do it all day and have a feel for it. You can learn to hand sharpen drills and get pretty fair results if you can find an experienced craftsman who knows what he is doing to show you the ropes. You need a grinder, drill gauge, a sharp eye, and a steady hand to sharpen a drill . I can do it in a pinch getting fair results but I'm no pro at it. I have watched a coworker 15 years my senior grind a drill in less than a minute. 

To sharpen a drill you need to understand the cutting geometry of a drill . You should be able to find some good info at the library in a machining text book. In addition to getting the proper clearance and rake of each cutting edge of the drill bit you need to keep the point centered. If the point is off center the bit will drill a larger hole than intended and not clear swarf properly. 

I do a lot of modeling in brass and sometimes use a " 0 deg rake tool" which is good for brass, bronze and copper. It is made by flattening the cutting edge by grinding just a bit which allows the cut to be more of a scraping action. 

Alternately you can buy a good new drill bit. The best are usually polished and preferably made in USA (yes there is a difference). Forget the black finish Chinese drill bits! More drill bits are dulled due to misuse and abuse than time drillng. I know that from experience! 

Regards, 

Jack


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## denray (Jan 5, 2008)

I agree with Jack, I had a General bit sharpener and a drill doctor, prefer the General. The drill doctor can put on the split point. the only problem is it takes somebody that can think practicle to run the drill doctor, you do have to think. The General is more intuitive, once you understand how it works. 
Personally my self, give me a good light and a belt sander, I am the guy that prefers to sharpen my bits by hand, with a good light and either a verticle or horizontal not flat. Start at the cutting edge and slightly roll the bit to either create the relief or keep the existing relief. I am quite aware not everybody can sharpen bits this way, not eveybody can sharpen bits with a high tec machine. Studying a bit and how it works can do a lot of good, knowing what needs to be done is half the battle most people have. to many people want a sharp bit, but don't put any thought to what needs to be done. 
It is really quite easy. 
Dennis


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## John J (Dec 29, 2007)

Do you have a link to this General Sharpener?


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## SteveC (Jan 2, 2008)

John

I believe this is the one being referenced.

General Tools - Drill Grinding Attachment[/b]


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## Totalwrecker (Feb 26, 2009)

Son of a gun! 
I bought one at the Gem show a couple of years ago, just because I liked the way it looked! 
Got it for $10. No instructions tho'. 

I still sharpen by hand... odd angle sharp is still better than precision dull! 

John


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## Madman (Jan 5, 2008)

Posted By John J on 13 Jun 2010 09:32 AM 
Do you have a link to this General Sharpener? 


Hmmmmmmmmmm. Look at my last post on this subject.


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## Madman (Jan 5, 2008)

Posted By denray on 13 Jun 2010 06:19 AM 
I agree with Jack, I had a General bit sharpener and a drill doctor, prefer the General. The drill doctor can put on the split point. the only problem is it takes somebody that can think practicle to run the drill doctor, you do have to think. The General is more intuitive, once you understand how it works. 
Personally my self, give me a good light and a belt sander, I am the guy that prefers to sharpen my bits by hand, with a good light and either a verticle or horizontal not flat. Start at the cutting edge and slightly roll the bit to either create the relief or keep the existing relief. I am quite aware not everybody can sharpen bits this way, not eveybody can sharpen bits with a high tec machine. Studying a bit and how it works can do a lot of good, knowing what needs to be done is half the battle most people have. to many people want a sharp bit, but don't put any thought to what needs to be done. 
It is really quite easy. 
Dennis 


The important thing to know about sharpening drills is to keep both sides of the cutting edge symetrical. Doing it by hand takes a sharp eye, and keen sense of how much you are taking off of each side of the point. The General drill sharpener takes care of that for you. Although you really should keep track of how many times you turn the bit in the jig. All in all, as I mentioned in my earlier post, I find it easier to use than the Drill Doctor.


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## hawkeye2 (Jan 6, 2008)

John,

I have one and a half of the General sharpeners and can send you the instructions however I have no clue how to do it usig the message service on this site. If you are willing to send me a message with your e-mail address I can send them to you as an attachment.

I purchased a General (Craftsman) drill sharpener and a side grinding wheel almost 40 years ago and highly recomend them. I tried a Drill Doctor but wasn't happy with the results. I learned enough from the General unit that I could freehand sharpen bitts up to 1.5" dia. using a gauge to check them and can keep a properly sharpened bit cutting fine just by eye.


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## Totalwrecker (Feb 26, 2009)

Hawkeye, 
Thanks forr the offer, but as most of my work is wood nowadays, my freehand sharpening is ok. 

I really plunked down the $10 because of the design, to me it's industrial art, a thing of beauty to behold! 

This thread gave it a name. 

John


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## SteveC (Jan 2, 2008)

John

If interested here's a PDF copy of the instructions.

General 825 Manual[/b]
[/b]


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## Totalwrecker (Feb 26, 2009)

Thanks, but then I'd need a stone grinding wheel, I'll keep what I have on the grinder and sharpen by hand on the flat lap.
My wheel is for finish work on non ferous.

I really did buy it as industrial art! Looks good in the workshop...on a shelf.









John


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## Dieselguy (Apr 29, 2010)

John J,

Another "Drill Doctor" user here and I don't have the "super" version...just an old #500 model. I've had mine for many years (I'd guess 15 or so) and have sharpened many bits on the product over the years. It is easy to use and consistently has gotten the job done in just a few passes. I don't know anything about their later models, but if they are anything like mine I'd say get one to anyone looking for a bit sharpener.


Rick


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## John J (Dec 29, 2007)

I think for the general all aroud hobbiest the Drill Doctor is a good tool


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## jamarti (Jan 2, 2008)

I bought myself the Drill Doctor for Christmas last year. I spent a good part of a day sharpening all my bits laying around and went looking for more. I thought it did a nice job when I went to use them. It did take some practice.


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## SE18 (Feb 21, 2008)

For those who sharpen by hand, do you just grab a file, set the bit down and file at the angle it's at? Since it's spiral, you'd have to file while turning it. 

I've never attempted any sharpening of bits. When they get dull, I use them as gauges for the table saw or for projects, as they measure perfectly. 


Dave


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## Totalwrecker (Feb 26, 2009)

Rarely will I sharpen with a file. 
I prefer a flat lap with sand paper ...er really wet n dry paper. 3m makes self sticking sanding discs in 8" and aprox a 1,200 grit. I use a rubberised grinding wheel, impregnated with abrasives and just stick the paper to it's side. I always grind from the cutting edge to the shank and a steady twist covers the curve. 
Nowadays you can find flat lap wheels that attach to grinders and will do the job. I wear optivisors and lay the heel to the wheel and slowly raise the shank until I see the edge being cut, too much and you'll likely gouge into the paper. 

I've been using the same Sargent drill index (1 to 80, decimal) for ...let's see got them in '78.... so 32 years! Always use oil when drilling metal and kept in case to protect the cutting edge. 
If I have a job that looks like will destroy the bit, I'll buy one for the job. 

John


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## SE18 (Feb 21, 2008)

thanks John, I like low-tech methods and will give er a try


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## Totalwrecker (Feb 26, 2009)

I also sharpen 61 -80 on the side of a seperating disc. Not all discs are the same, I like a fine grain disc, moderate speed and pressure proprtionate to size of bit. 
I use my fingers to hold these. 
Watch the edge! 

Same aproach as above. I rarely get a factory edge, but good enough and faster than a trip... 

John


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## wigginsn (Jan 9, 2008)

I haven't had to do it for quite a while now but we had to sharpen drills by hand for our trade tests. I remember the Tutor was rejecting anything that didn't meet his high standards (unreasonably high to my 18 yr old brain). We consequently got a lot of practice... 

Same technique as John, smooth grinding wheel, lay up the cutting edge to the wheel then a roll & twist to get the angle. Once you got the hang of the action it comes easy and as mentioned, 30 secs on the wheel is faster than heading off to town to buy a new one.. 

Cheers 
Neil


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