What is the best tool or jig to accurately sharpen drill bits?

>>1050922

I use one made by "Darex" but "new" it's probably outside the price range of most hobbyists.

If you hit up some machinery auctions you might pick one up cheap though, and they are very very accurate.

>>1050923
darex sells drill doctor

i wonder what they stripped out for the consumer version


---
i just buy loads of cheap drill bits. although slowing down and feeding at the right rate is the right thing to do

>>1050922
>What is the best tool or jig to accurately sharpen drill bits?
The top drill doctor ($130) is really the best thing there is, until you spend $1300 or so for the cheapest Darex model there is. Or there's ancient things like Quorn cutter grinders, if you want a whole new hobby.

>PS I don't believe in doing them by hand with a grinder since deviations in the bevel lengths results in oversize holes which especially leads to problems when tapping holes
What you can do is have a set of hand-sharpened drills for most drilling, and then a set of new still-factory-sharp drills for finishing holes.
If you need a perfect 3/8" hole, you use one of the hand-sharpened drills to make a hole 1/32" undersized, and then use the new 3/8" drill to bore out the final hole.

The main problem you get when using hand-sharpened drill bits for metalworking is that the point isn't centered, which leads to off-center holes.
The way you get around this is you use a drill press or mill, clamp the work piece and you step-drill up from a small size.
Such as: to drill a hole 1/2", you first drill a 1/4" hole, then a 3/8" hole, then a 13/32", then a 7/16", then a 15/32", and finally the 1/2". Each hole will be more-centered than the last.

I've not found tapping to be greatly critical of hole size, but then I don't know what you are doing exactly.
If you are using spiral-point or spiral-flute taps, you can drill the hole a few thousandths under and the tap will just cut it out anyway.

We hand sharpen drills all the time at work and don't have an issue. Just gotta get good at it. If you're worried about off center use a center drill first and solve your problem. However if you insist it's an issue a drill doctor machine will work fine.

BTW the angle can't really make an oversize hole since the diameter of the drill is set no matter the taper. You might be off center or oblong but you're not going to get an oversized circle.

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Don't buy any of those single use drill bit sharpening tools. They are a waste of money and when the sharpening stone (or 'diamond or what have you) wears out you have to spend 4/5ths the cost of the machine to get a new one. Get a sharpening jig for use with a grinder. If you really want to get fancy you can also buy special rulers and guides that you use to check the angle on the bevel and such. This is how machinists have been sharpening their drill bits for a hundred years.

>>1051043
>using the side of a grinding wheel

exploding_5_pound_stone_wheel_3500rpm_bestgore.com.webm

>>1051048
They're designed for that. It's made for drills.

>>1051048
>every stone is the same one as the default one that comes with your $40 grinder

Also, hand sharpening using a drill gauge for reference gets it good enough for most usage. Just be sure to provide clearances.

>>1051043

This is the correct answer. The Drill Doctor and similar shits are basically passable gimmicks for homeowners. If you're working with metal often enough to worry about accurate sharpening of your drill bits, you must certainly have a grinder already. A jig will work better, be more versatile, and probably be cheaper than a dedicated tool. A grinder and jig was how drill bits were manufactured in the first place.

Well, used to be. They're all CNC ground, now.

>>1050922
>problems when tapping holes
But oversize holes make tapping easier. What's the problem here?

>>1050969
If the point is off center, the center will dig in and spin in place, making one side extend out farther from the center of rotation than the other, which produces an oversized hole.

I'd say learn to sharpen freehand for general use, and grinder with jig for precision. Learn how to grind flat facets. http://www.mmsonline.com/articles/choose-the-best-drill-point-geometry

Am I the only one who figured out you can use a drill to even out the angle of a bit?

1. put bit in drill
2. Grinder on
3. drill on
4. grind bit

There, it's even, more even than your fucking chimp hands could ever get.

>>1051159
But then you still have to sharpen it. And since the relief has to be entirely reground now, it will be harder to maintain evenness than with just touching up the bit in the first place.

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This page shows some pretty nice DIY setups from amateur machinists. Note that all of them use diamond cup wheels and not bench grinder wheels.
http://www.gadgetbuilder.com/DrillSharp.html
You can't cut split-points on a bench grinder wheel, so for that reason alone a lot of people consider it to be an unacceptable method.

Study all those photos a minute and you may notice something: all of them are only grinding flat facets....?

The drill doctor's main innovative feature is that it uses a bit holder with a helical groove, that allows you to accurately cut a curved relief angle.
Drill bits for a hand-held drill or manual-feed drill press work better with a curved relief, as it helps prevent feeding too fast.
Drill bits for CNC use tend to just use flat facets, since a CNC machine always feeds the drill at the proper rate for whatever material and RPMs it's set to anyway. (Pic related)
In that respect, the drill doctor is targeted at the home and hobbyist market.

You can sharpen drills by hand on a bench grinder (even I do it with the crappy bits) and they'll keep making holes but they're not really 'good' anymore.
All the angles and grinds for both flutes must be perfectly even and centered for it to work correctly.
Claiming that you can do that by hand is a lot like someone claiming that "they don't need to use rulers anymore since they can just cut stuff the exact size they need by hand".

>>1051289
>all of them are only grinding flat facets....?
Because flat facets cut better. If it digs in too fast for a hand drill, you reduce the relief angle, which also has the effect of strengthening the cutting edges. I commonly work with stainless, which needs an aggressive feed rate while also subjecting the cutting edges to high heat and wear, so flat facets are de rigeur.

>Claiming that you can do that by hand is a lot like someone claiming that "they don't need to use rulers anymore since they can just cut stuff the exact size they need by hand".
Except that I can do it by hand. I can sharpen bits down to around 3/32" by hand better than they come new. So that's what I usually do. Git gud.

>>1050956
A touch of oil helps as well.

>>1051592
>Except that I can do it by hand. I can sharpen bits down to around 3/32" by hand better than they come new.
Suuure you can.

>>1051628
And? As I hold such a bit in my hand, do you think your skepticism impresses me? Is it so hard to believe that there are people who can do things that you can't?

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German machinist and engineering technican here. I always sharpen my drill bits by hand, but I use a disc sander. It has a nice big surface to rest your hands on, and it always works like a charm. Light your workspace well, and use a caliper to measure the cutting edges to make sure they are equal in length. Have a big factory new bit serve as a model when you sharpen for the first time until you know how all the relevant angles and surfaces have to look. The drills I sharpen come out working perfectly, and is really only a matter of 30s or so to do it. It's so fast and easy I really do not think about it, it's a task as normal as using a screwdriver or putting safety goggles on. The smallest bits are 1mm in diameter, but I do those on a grinding disc on my dremel.
If I need most precision in hole diameter, I pre-drill 0.5mm to small, and then open up the hole with the right diameter drill. I fold a playing-card-sized piece of cotton cloth a couple of times and place it between the work piece and the drill bit when I work with thin materials as sheet metal to center the drill better and prevent it from getting stuck and flign the sheet metal around. I always get excellent results with my hand-sharpened drills, and I believe everyone can who has not suffered from a lack of oxygen during his birth.

>>1051628
You totally can do a high quality job by hand though. What, do you think that our tool grind department sharpens every drill by jig? They'd be buried in them. I've inspected them before on a comparator. The old hands really can achieve in-spec drills by hand.

>>1051683
>And? As I hold such a bit in my hand, do you think your skepticism impresses me? Is it so hard to believe that there are people who can do things that you can't?
If you are asking me if I think you--or anyone else--can grind both flutes of a drill bit to an exact angle within, say, 1/10th° by hand, centered within .001" and with both flutes the same height better than .001", I'd say no.
You can't.
No human can.
To claim as much is silly.

I already said that one can sharpen dull drills on a bench grinder, and make them drill holes again--but bench-grinder drill bits make crooked holes.
If you step-drill you can reduce the problem, but any bit sharpened this way isn't going to work correctly.
Go bother the guys on Practical Machinist if you don't believe me, and ask them what they think of this matter.

The Delta 1293 shown on the gadgetbuilder page dates from WW2. It uses a bench grinder, but it's still not by hand. And it's 70 years old.
Shops that want precise holes do not regrind their drill bits by hand. If they want precise holes, they haven't been grinding drill bits by hand for a long time now.

OP asked for " the best tool or jig to accurately sharpen drill bits", and (for metalworking) hand-shaping them on a bench grinder is about as far from accurate as you can get.
It's cheap and quick, but for precision it quite plainly sucks.
The top-model Drill Doctor is about as well as you can do, without spending a whole bunch more money to build your own diamond-cup setup or hunting down a real (used) cutter grinder.

>>1051048
>>using the side of a grinding wheel

Is fine with correct wheel. Study moar.

>>1051733

I guess the fact that you are german makes your post more relevant...

I'm a redneck A&P guy here. I use a belt sander to sharpen most bits. It works pretty well, but eventually the bit is just worn out and you cant keep the same edge again.

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If you really want precise holes you ream to size rather than drill.

A Drill Doctor will more than pay for itself IF you do enough bits, but if you buy common bits in bulk you can just throw them away for a reasonable cost per hole.

Buy bits online, not at hardware stores. It's often not worth shop labor to sharpen bits even with all the goodies like tool and cutter grinders.

It's usually worth sharpening large bits and milling cutters though, but many shops just fill a bucket and send that out.

If you don't mind moving them you can find used tool and cutter grinders reasonably but it may take a while. My machinist bro got a Darex in trade for two hours of work from someone who never used it. I got a Hammond for fifty bucks but I'll have to install a single phase motor (five bucks, already have) and a tool holder plus grinding wheels.

Overkill, or maybe not, is this LeBlond my bro scored for his home shop for about 350. He'll need a phase converter or VFD but we have those. The mills it sharpens will pay for it easily.

>>1051902
>I guess the fact that you are german makes your post more relevant...

It does. German trades education and training make their US equivalents look a joke by comparison. Machinists there get some respect. US machinists rarely make good money. (See the Practical Machinist shop owner section if think I'm kidding.)

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>>1051906
I get what your saying, but I just looked at Maschinist job openings in Frankfurt. Sure the job offers 3800 euros a month to start, but cost of living is through the roof compared to the states...

On top of that the 3800 euros a month is only about 4300 USD a month. I easily make more than that as a freaking car salesman in Atlanta, where real estate is 44% cheaper than Frankfurt, and I've only been selling cars for a year.

Here in the USA, in 2012, a machinist makes 3409 usd median a month starting. Adjust for 4 years of inflation and they probably look pretty close.

I don't buy what your selling bro.

>>1051906
>It does. German trades education and training make their US equivalents look a joke by comparison. Machinists there get some respect.
Sure, that's why Germany was the first country to build the Space Shuttle. Oh, wait, no they didn't....

>US machinists rarely make good money. (See the Practical Machinist shop owner section if think I'm kidding.)
This really gets into a lot of other things about economics rather than machinist skills.

In the US companies that enjoy trade protectionism (the defense industry) the pay is still quite good.

Most other US industries are stuck competing with China pay rates, which they can't very well do. (...Nor can German shops, I'd dare to say...)

>>1051945
>Most other US industries are stuck competing with China pay rates

only shit tier manual job shops. if you aren't lights out in america you are doing it wrong.

american manufacturing is archaic in its integration of technology.

>>1051954
obvious troll is obvious

>>1051963
oh yeah? then why are guys who can drive 5+ axis or do CMM able to hold entire shops hostage?

every machinist is
>muh knee mill
>muh engine lathe

most machinists can't even import a solid or change coordinate system in CAM, let alone do any process design requiring MTM.

>>1051881
>If you are asking me if I think you..
Might want to set that goal post down before it gets too heavy.
>>1051592
>I can sharpen bits down to around 3/32" by hand better than they come new.
That is, they work better for my uses than a new bit. This really isn't hard with the 118 degree standard points most common in hardware stores. Angles to 1/4 degree, centered to .003". Flutes even to .001 is tricky but doable if I want to bother, but since it doesn't matter for anything I do I usually don't. Since I never in my life have had to drill a hole with upper tolerances tighter than .01", this is plenty. And more on point, my hand-ground flat-faceted bits cut faster and more evenly with less pressure, and last much longer than anything I've found in stores except split points. If I were a machinist who had to maintain .001" precision in every part of a project, I'd use a jig. But I'm not, and neither are most people.

>>1051954
wat. Job shops are secure as far as outsourcing goes just due to the nature of their work. It's the cheap/simple mass production shops that lose their shirt.

>>1051945
>Sure, that's why Germany was the first country to build the Space Shuttle. Oh, wait, no they didn't....
murricans built space shuttle only because of German's works on V series rockets

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Wat do?

t. mr wood

>>1052315
Grind a standard angled point on it and get a new bradpoint.

>>1052249
WWVBD

Von Braun, fuck yeah!

holes under .25 inch or 6mm: buy a new one.

Holes over that size and you don't want to free hand? Drill Doctor professional model.

If you're not willing to freehand, there's no super cheap way to do it since you've eliminated the only really cheap way.

>>1051902
Take it easy bro. I'm just mentioning my nationality on occasion to point out that english is my second language, and thus my wording may be less than perfect. I do this in order to prevent people from doubting my general abilities just because of sme por writing here and there.

>>1053524
See, I forgot the "o" two times ;-)

>>1052315
These are not hard, but time consuming. I use a flat diamond card to hone the cutting edges. Six of them in total, the two spurs, the primary bevel, and both sides of the center chisel. They're just tiny spade bits.

machinistfag here

I use a bench grinder. I dress it just a little bit, just to get a spot on the wheel that's flat. I see a lot of people dressing the wheel down like a quarter inch, you don't need that, just the "highest point". Makes the wheel last longer.

I'll often keep a good drill bit to compare while I'm grinding. There are also drill gauges that make it pretty easy.

Then I put it on the drill press, and with a piece of offcut/scrap at slow RPM see what the chip looks like, if it's even on both sides I'll speed it up and make a hole and check the size if the size for the job is critical.

I still remember the courses I took in college about machining, we spent a good day just for regular drill bits. We spent hours practicing how to grind it properly, what the various grind angles were for one type of drill bit grind (118 versus 135), how to do split-points, and so on.

I've been in two shops with drill doctors, both times they weren't used and when I did try to use them out of curiosity, it took longer and was more trouble than doing it by hand. I've sharpened drills a little over 2" in diameter on big grinders by hand just like I've sharpened drills around 1/8th of an inch.

tl;dr get gud I guess, buy some cheap chinashit drills to practice on