Drill bit sharpening....Fact or fiction?

Learn to do it right, then buy a drill doctor to save time. I had to learn at school, the teacher gave me a pile of old drills, ground the ends flat and got me to go.
If you put too much relief it will try to screw the drill into the hole and will go blunt fast. Not enough and it won't cut. It's tricky, but after a while you just know how much is needed. The drill gauge shown is almost exactly what I use, I made mine with holes in it to find the right diameter drill to, but I never use that. Normally when I'm sharpening a drill I'll check the angle, the length of the lips (cutting edge) with a rule and when I think I have it right I put it in another home made gauge, a bit of strap with a small cone welded to the botom. You mark the strap with ink, scratch one lip across it, turn the drill and do the other. If youve done it right youll get one line.
These drills last me just as long as a new one, the trick is to cool it after EVERY grind, if you get HSS hot it will soften and go blunt quicker. SO just don't rush it. Get someone who know how to show you, it really does have to be explained in person.

 

oh PS, have you ever seen someone sharpen a drill for mild steel then try to drill bronze? Haha, they'll crap their pants.

 

Bronze and brass actually requires dulling the bit some. Or cheaning the angle can help too. I sharpen all my shit by hand but i learned when i was about 15 or 16.
Dave

 

Anybody want a Driil Doctor? There's two laying out in the woods behind my shop...bought the first one (the cheap ,early version) ..tried over & over & over to get it to work...got pissed one day..ripped that sumbitch out by the roots and flung that POS down in the woods...calmed down a few months and bought one of their top of the line diamond wheel gadgets.. Tried a few hunnert more times ...and that one joined the other one in the woods..I must be jinxed or a real klutz...Hell ,I can't even sharpen a pocket knife..I coulda bought a whole lotta new bits with the money I wasted..besides ,my drillpress spins so fast anything 1/2" or over ,I go use my buddies vertical drill and dull up his bits...

 

Drill Doktor wurk good for me and I haf no thumbs.
I read dirkshuns printed in engleesh on bak. work gud evry tim since den.


(sorry-I know I'm a smartass. but really guys, it won't do them for you, but if you read the directions, it works great. I know this cause I had it all figured out till I ruined about 12 bits trying to figure it out how to do it...then I read the directions.)

 

It usually doesn't take much grinding to get bits sharp again. I have a cheap small grinder that I got years ago, that I only use for sharpening, so the wheel stays dressed pretty well without any effort. Only takes a few seconds to clean up a drill bit, once you figure out how, and it gets to be a habit before starting a drilling job to touch up the bit.

 

You guys would probably die if you ever watched me sharpen drill bits. I have a nasty old 1 hp bench grinder with no guards and no tool rest. It has what used to be a 6" course grinding wheel on one side and the wire brush on the other side. I've owned this thing for over 20 years and it was used when I got it. I'm not real sure there is any part of the grinding wheel that is straight anymore. I sharpen the drill bits off the side of the wheel by hand.

This afternoon I drilled 4- 3/4" holes in 4- 1/2" thick plates and then drilled 4 more 3/4" holes in a 2 ton truck frame from the bottom up all with a hand held drill. I started with a 3/32" then stepped up to a 3/8" then to a 1/2" then a 5/8" and finally the 3/4". The whole process took about an hour with drill bits I sharpened on my grinder.

I should probably buy a drill doctor, or at least a new grinding wheel. I should put the guards back on the grinder, but I'l have to make them, I don't think it ever had the guards. I'll bet my insurance guy would have a heart attack! I have a newer, smaller bench grinder with all the guards and stands, but this old pig works so good, I'd hate to toss the old girl out...
Gene

 

Yup, that's what I've done. Works pretty well. Not to be a smary aleck, but are you sure it is turning in the right direction and at the right speed? A couple of nights ago I wasn't paying attention and wondered why my drilling was going so slowly through plastic and sheetmetal -- it was spinning backwards.

Make sure you go slower with big bits or they'll turn blue and lose their temper. Also, make sure you clean off rust before you drill.

 

yup... drill doctor to the rescue. if you think you can do it by hand as good as a drill doctor you are sadly mistaken.

and I'll wipe my own ass thank you.

 

I can't do it by hand as good as a drill doctor, but I can sure do it good enough....

 

3/4" inch is huge.

Use the plasma cutter.

It's faster.

Rob

 

I don't have a problem with dull drill bits, my problem is the dull person doing the drilling, hey you guys know that concrete bits wont drill steel? Not even gonna tell you how I know that......
The only problem (Potential problem) with sharpening a bit is overheating and softening the steel, don't happen often but when it does the bits is RS.

 

We have 150mm, almost 6", drills at work. Plasma cutters don't cut through blocks 400cm thick. Sharpening the really big ones is a bitch, but they only really cut on the outside 20mm, so as long as that's good it's fine.

 

Why would you use a six inch drill and not a spade drill with coolant holes?

 

Anyone have a Drill Doctor 500x that they do not use and want to sell, send me a P.M.

 

Drill doctors are great,If you can't sharpen a drill with one you are a moron.Get someone to help you.Have two, one at shop one at home they work great.

 

Damn, Flatdog; wish you lived closer to me!!
Then YOU could help ME!!

 

Way back when I started my millwright training I was giving an old piece of crap drill sharper that clamps to the tool rest and has a protractor type of
adjustment to set the angle of the flite you want grounded . them you clamp
the bit under a upsidedown U [sorry sounds dumb to me also] then you swing
the bit to the side ,start grinder,swing drill bit held in device side to side on grinder stop rotate drill and do other side .less time to do than to write it down I get two curls out of a hole I drill must of the time for last 40+ years.

 

I have a drill doctor,I have never been able to get it to sharpen bits,I feel I have been screwed. 75.00 takes this damn thing,lemme know....ron at [email protected]

 

I got a drill doctor at sears on sale for about $60. a few years ago. I really like it, I should have gotten one a long time ago,it would have saved me money spent replacing electric drills that I burned up trying to drill with dull bits.

 

The 6" drills are probably older than I am, they hardly get used, anything that big normally gets cut on a CNC, but they have come in handy before because they're so long.

 

We have room, come for a visit.

 

Spend the time learning not only how to sharpen drill bit but fixing taps that break. I broke a shit load of taps in gunsmithing school doing blind taps on Mausers for scope mounts.

 

Years ago, when I worked in a machine shop ... whenever a guy applied for a job and claimed to have machine shop experience ... before we hired him as a experienced hand ... he would have to shapen a drill bit. If he could not shapen a drill bit ... NO JOB !!

Cutting metal to lenghts was the entry level job ... then the drill press ... before you ever got to run anything else. If you could not shapen a drill ... you had not progressed very far in the machine shop world ...

 

I sharpen bits with a grinder,by hand, most of the time it takes a couple of tried to get it right. As far as keeping the bit sharp, go slow, the bit cuts more metal and stays sharper longer. Also, I use bar oil (for a chainsaw) for cutting oil, it is REAL thick and , it works great. If you do not have any bar oil, buy you some and try it , it works great.

 

I'm cheap, so I didnt buy a new drill doctor. I hand sharpened my bits when they went dull(which was often becuse I couldn't sharpen them very well) My Ma got me a drill doctor from a rummage sale for $10. Best invstment ever. Now even my 60 piece $20 harbor feright drill bit set cuts through steel no problem

 

One of these days, one of these days!
(and we can do some "flathead" bench racing!)

 

I too am in the market for a Drill doctor.

 

anyone mentioned the hex nut trick??? you hold two hex nuts together side by side and the angle where the angled side from each nut comes together at a point is the angle you need for your bit. works with any size hex nut. you can use that as a guide to make sure your keeping it the right angle when free hand sharpening your bits. learned that from an old timer when i used to work in the blacksmith shop.
i picture would make this crystal clear but i don't have one at the moment.

 

It's not right on, but its pretty god damned close! Close enough that if you have any sense while doing it it should work okay, that's for sure.

*** Two nuts butted would be a 120* angle. In machining 118* is taught as the general rule of thumb angle for metalwork... of course, it all changes depending on the metals, alloys, or other materials...