Pointers on drill bit sharpening, pls

[cranetruck]

I have accumulated a large quantity of drill bits, mostly because I tend to get a new one instead of sharpening the ones I already have.
I can do a fair job with the bench grinder, but not like new.

Question 1: Good sharpening techniqe, please describe.
Question 2: Good electric sharpener? Attachement for bench grinder?
Question 3: What angle for what material?
Question 4: What is a good drilling speed for a given material and bit size?

Thanks.

 

[BillIdaho]

As a 26 year veteran in a machine shop, sharpening bits, cutters, drills, etc became second nature.
As far as technique....find another old machunist and have him show you. Describing it over a keyboard would be impossible.
The actual type of sharpening device depends on a few things. If you have a meduim sized grinder, suitable for attaching a sharpening fixture...that works pretty good. It is a odd looking thing that bolts on the frame of the grinder. The drill bit sets in a tray and you simply traverse the bit back and forth, rotating it a little each time. Time consuming, but accurate.
The angle does depend on the material being drilled. Google "Machinist handbook" and you will find the exact angles relative to the materials. ( I did learn a trick for drilling brass and other soft metals that REALLY helped me. I wouild somehow have to once again SHOW you, I couldn't begin to describe it, but it works!)
Speed of the feed AND the speed of the drill makes all the difference in the world. In other words, how hard you lean against the drill pushing it into the metal is as important as how fast the bit is turning.
Our shop used several different cutting fluids. Some were oil based, and others were water based. Either way, usually, you want some type of liquid help.
Without sounding like the "know-it-all" everyone knows, I have become quite, shall we say,proficient at sharpening things. If you were close to Boise, you could drop them off at my house and I could dress them up here in a day or so. You might be able to find a local shop that one of the guys wouldn't mind taking a few minutes out of a break, for the mere price of a 12-pack to do them for you.

 

[TacticalTruck]

I've had good luck with my drill doctor
http://www.drilldoctorstore.us/drilldoctor1.html
Idiot proof and fast. Also good advice on getting a machinist handbook.
Jeff

 

[jasonjc]

I too have the Drill Doctor. It works great. fast and easy.

 

[gringeltaube]

Once you know what shape it has to have and how it has to look like, the rest is trial and error plus practice, practice..... (Übung macht den Meister, Bjorn!)
Some little tricks might help, like i.eg. imagine the MB star when checking the cutting lip angle. Also check for some (but not to much) lip clearance. To much and the edges will break out, if not sufficient it just won't cut.

My

 

[WillWagner]

ditto on the drill doctor. It even does the little back cut thing at the tip. Does real small bits too!

 

[cranetruck]

Thanks for your inputs! Yes, Gerhardt, practice makes perfect.
I'm looking for a Drill doctor, should clear up part of the space on the work bench.

I suppose that the answers here are not news to me, just good to see how the rest of you handle the "little things" around the shop. Back in '61, I worked in a drilling department at a clock factory in Augsburg...brings up memories.

 

[TacticalTruck]

Here's the machinist handbook on ebay
http://cgi.ebay.com/ws/eBayISAPI.dl...loc=closed_view_item&refwidgettype=osi_widget

jeff

 

[No.2Diesel]

If you look in the latest issue of Homeshop Machinist Magazine, there is an article that illustrates how to make a drill sharpening jig. The Drill Doctor appeals to a much greater audience though and is a very good invention. Gerhard, I enjoy your sketches. Do you ski in Bariloche?

 

[bigmike]

Being a machinist I also agree that it's too hard to describe with a keyboard. I also agree with the drilldoctor recommendation.

 

[Jones]

Drill Doctor, hands down. I've been doing machinist's work for years and only know one person good enough to sharpen drills by hand... and it ain't me!
A copy of machinery's Handbook is good to have. If you're into older repair processes; several of them maybe a decade apart are invaluable. Unfortunately, as newer material is added, some of the older obsolete info has been deleted from the later editions.
In addition to methods of repairing stuff that currently isn't designed to be repaired-- just replaced; there are also ways of laying out and figuring angles, computing areas of really oddball shapes and such, that come in real handy in case your CAD program crashs.

 

[gringeltaube]

Gerhard, I enjoy your sketches. Do you ski in Bariloche?

Thanks, sometimes better than words...
I used to, 30 years ago!

 

[amanco]

Has any one heard of Rodman drill bits? I saw a demonstration at a trade show and the fellow had about a 3/8" bit in a drill press and drilled 5 or 6 holes into a high-carbon steel file then several holes into a ceramic tile and then into a 2x4 twisting it left & right to show the bit when hot was not brittle and then a couple more holes in the steel file. It was amazing. Fire was coming off the bit while drilling thru the file. At the trade show the demonstrator said the bits have a life time guarantee, if you ever break a bit you can mail it to them and they send a new one free of charge. Supposedly you can drill through cast iron, metal, steel, concrete, granite, ceramic tile, marble, porcelain, glass, crystal, wood and plastic. Any one out there use any of these bits? They also sold a stone to dress the bit if it dulled.

I have a copy of the machinist’s hand book. I can just sit and read it for hours, really neat stuff!

 

[micmccon]

I would add my to the Drill Doctor discussion. I have used mine for years and LOVE IT! I also reccommend the reverse twist adaptor and sharpen up all your left hand twist bits too. I've been a mechanic for 20 years and still use my original Snap-on drill bits and they sharpen right up. I sold a buddy on the Drill doctor when I took one of his old dull bits and sharpened it and then proceeded to drill through a brake rotor (discarded rotor) in about 30 seconds! It is as easy as using a pencil sharpener!

 

[3dAngus]

Did you, by chance, buy that 2400 lb. load of new and used drill bits from GL last week?
That was a mess of drill bits.

 

[197thhhc]

You cant go wrong with a drill doctor. I have maintained the same set of bits for years and I use them daily .

 

[Boss Doug]

Drill Doctor!!

 

[Takai13]

Went through the plant in Ashland, OR years ago while training in Lean Manufacturing and VSM principles. THeir process is as good as their product.

 

[DAP]

How does the Drill Doctor compare to the cheapie they sell at Northern

 

[Verkstad]

Do