Drill Doctor

cmyoung2 · Jan 4, 2012

Thanks for everyones input on the Drill doctor. I ended up with the DDSB, does both twist(up to 1/2) and spade bits(up to 1 1/2). I also got a 6" bench grinder, been wanting both for a long time. The Drill Doc works, is easy to use, think it will pay for itself in reclaming old bits. The grinder is a little harder to learn, but not bad. For me, it works better on the larger bits. Do have to pay attention to keeping everything centered. Again, thanks for everyones input, have a good new year.

5030 · Jan 4, 2012

cmyoung2 said:
Thanks for everyones input on the Drill doctor. I ended up with the DDSB, does both twist(up to 1/2) and spade bits(up to 1 1/2). I also got a 6" bench grinder, been wanting both for a long time. The Drill Doc works, is easy to use, think it will pay for itself in reclaming old bits. The grinder is a little harder to learn, but not bad. For me, it works better on the larger bits. Do have to pay attention to keeping everything centered. Again, thanks for everyones input, have a good new year.

...once you master the art of offhand grinding, the drill doctor will collect dust because offhand grinding allows you to vary not only the cutting angle but the relief, which is very important on larger bits. As you get proficient, even the tiny bits are doable. I use a magnifyier headgear to sharpen the tiny ones and a grinding wheel mounted in Dremel laid on the bench.....

grsthegreat · Jan 4, 2012

cmyoung2 said:
Thanks for everyones input on the Drill doctor. I ended up with the DDSB, does both twist(up to 1/2) and spade bits(up to 1 1/2). I also got a 6" bench grinder, been wanting both for a long time. The Drill Doc works, is easy to use, think it will pay for itself in reclaming old bits. The grinder is a little harder to learn, but not bad. For me, it works better on the larger bits. Do have to pay attention to keeping everything centered. Again, thanks for everyones input, have a good new year.

Congrats... no matter what some people here say about the drill doctors, they work GREAT and are easy to keep an edge on your bits.

Some old farts sure hate progress HAHA....and that means something coming from this old fart

digger2 · Jan 4, 2012

I have an older model DD and i think they are great.Just make sure you get a couple of spare diamond wheels to replace the original.They do wear out eventually.Personally,i think the bits cut better than when they were new alot of times.
And yes,i do know how to sharpen a bit by hand on a grinder,but I cant come anywhere close in accuracy to what the DD will do.

digger2

crazyal · Jan 4, 2012

I love hearing how machinists will not talk about something like the DD. Like somehow if you use one you're not a purist. Well I bet using my chainsaw over an ax to cut down trees and using my log splitter over a splitting maul also may be frowned at by some as "cheating". I bet they would say if you take the time to learn how to cut with an axe you'll be able to 'read' the tree better. I'm also sure that the same holds true for the maul with learning how to read knots. But they would be the minority.

Congrats on the sharpener and grinder. Hopefully your bench grinder doesn't get put on a shelf and collect dust like mine do. Between my 4 1/2" grinder and DD I just find the real estate on the workbench too valuable to give up to a bench grinder.

grsthegreat · Jan 4, 2012

crazyal said:
I love hearing how machinists will not talk about something like the DD. Like somehow if you use one you're not a purist. Well I bet using my chainsaw over an ax to cut down trees and using my log splitter over a splitting maul also may be frowned at by some as "cheating". I bet they would say if you take the time to learn how to cut with an axe you'll be able to 'read' the tree better. I'm also sure that the same holds true for the maul with learning how to read knots. But they would be the minority.

Congrats on the sharpener and grinder. Hopefully your bench grinder doesn't get put on a shelf and collect dust like mine do. Between my 4 1/2" grinder and DD I just find the real estate on the workbench too valuable to give up to a bench grinder.

hehe...good one. my bench grinder is only used for the wire brush on the other side. i hardly ever use the grinder.

Kyle_in_Tex · Jan 4, 2012

If there's a DD or equivalent that can do a great job on an 1/4" split point cobalt drill, let me know about it because I haven't found it. We even bought a $3000 plus drill sharpener and I was not impressed with it. Nothing compares to a good factory sharp Chicago Latrobe M42 Cobalt drill for most metals. (Some metals demand coatings).

If you are just fabbing plate steel and don't mind drilling a 1/32 over the drill's intended size, hand grinding is fine. DD is good for home and hobby use. The wheel or stone is half the battle. Diamond or Borazon works the best.

When you have a CNC mill that you are charging $100/ hour, using cheap drills that don't last doesn't make sense. Buy cobalt drills. For a CNC with controlled feed, coolant and rigidity, get them coated with TiCN or TiAlN. When you are costing $3/minute, it doesn't take long to do the math of sharpening a drill vs. replacing it on drills smaller than about .200" diameter. Chunk those in a can and give them to your hobby buddys to sharpen on their DD.

PS, I can even hand sharpen carbide gun drills (if I have an optical comparator).

Shield Arc, on your picture of your $39 bench grinder, I believe you have your "tungsten only" label over the wrong wheel.

Shield Arc · Jan 5, 2012

Kyle_in_Tex said:
Shield Arc, on your picture of your $39 bench grinder, I believe you have your "tungsten only" label over the wrong wheel.

Why would you think that?

Kyle_in_Tex · Jan 5, 2012

Shield Arc said:
Why would you think that?

It looks from the picture that your "wide" wheel on the right is a bit green tinted for carbide. Hard to tell exactly from the picture.

Shield Arc · Jan 5, 2012

Kyle_in_Tex said:
It looks from the picture that your "wide" wheel on the right is a bit green tinted for carbide.

Yes it is.

dstig1 · Jan 5, 2012

Do these DDs work on step bits at all? Mainly the initial point is what gets dull fastest.

mwb · Jan 6, 2012

No they won't work for step drills. I would think the only way to sharpen them would be to regrind the flat side (not the side with the numbers).

murphy1244 · Jan 6, 2012

For ten bucks a set toss them and buy new ones..:laughing:

dstig1 · Jan 6, 2012

Good step drills are far more than $10 a set... The tip is the thing that really needs re-sharpening on them. Once the tip breaks through, they go real easy. Nothing better for drilling thin metal. They don't catch and you actually get round holes...

J_J · Jan 6, 2012

I thought I would throw this in the pot.

Tool geometry[1]
Workpiece material Point angle Helix angle Lip relief angle
Aluminum 90 to 135 -- 32 to 48-- 12 to 26
Brass ----- 90 to 118 -- 0 to 20-- 12 to 26
Cast iron 90 to 118 -- 24 to 32-- 7 to 20
Mild steel 118 to 135 -- 24 to 32-- 7 to 24
Stainless 118 to 135 -- 24 to 32-- 7 to 24
Plastics 60 to 90 -- 0 to 20-- 12 to 26

Diamondpilot · Jan 6, 2012

I love mine. Got it from the SIL 5 years ago for Christmas. I have save $100's with it. I spent a day sharpening my bits and my neighbors. Its been a life saver and time saver many times when drilling multiple holes in steel like on trailers that I work on.

Chris

mwb · Jan 6, 2012

dstig1 said:
Good step drills are far more than $10 a set... The tip is the thing that really needs re-sharpening on them. Once the tip breaks through, they go real easy. Nothing better for drilling thin metal. They don't catch and you actually get round holes...

The step drill wouldn't fit into the doctor - the tip would be a great candidate for sharpening by hand on a bench grinder.

SPYDERLK · Jan 6, 2012

FredH said:
I broke a 1/2" bit when a piece of steel flipped around and came down on the end of the bit in the drill . Clean straight across break , took maybe 5 to 6 minutes and although it is about 1" shorter now , Just like brand new .
Opinions are like a certain part of human anatomy , We all have one .

Fred H.

The center web of the spiral gets thicker as you move up the drill bit. ... therefore its not possible that it is like new.
larry