drill bit sharpener

I am pretty much a klutz when it comes to sharpening. I am smart enough to realize it, but I'm still a klutz.

Some years ago, I bought a Drill Doctor 750. I had variable results. If I followed the instructions, I often had 0 or even negative relief on the cutting edge. Some drills came out pretty good. I often tweaked the adjustments to get some relief.

A few months ago I notice a redesigned drill doctor at Lowes. I talked to the tool guy and mentioned my variable results. He said that if it didn't work out, just bring it back. I couldn't lose!

This was the model XP drill doctor. I have been very happy with it. It gives good relief on the cutting edge and when I put the drill in the lathe, I get two cuttings coming out. I've used it on some pretty small drills (just for a test, I'd probably just buy a new one when they are around 1/8 and below) and up to 3/4. The results have been consistent.

I fully admire anyone who can sharpen drills by hand. But as Clint Eastwood has said, "A man has to know his limitations." Mine seems to be in the sharpening skills, so any thing that can help me and take away the knack that I seem to lack, I'm in.
 
Mightymouse said:
Why have that contraption taking up space? Grind them yourself......

As an apprentice we were given a collection of drills to sharpen by hand and you did not stop until every drill had drilled a hole in Mild Steel.

Have hand ground rads on milling cutters and got better finishes than from bought in tools. Try it......it is not as hard as you think.

Trevor

PS, if anyone wants any tips on hand grinding drills post here and I will produce a guide with pictures.....
Click to expand...

Hell yeah :-) ,

any tool sharpening and grinding info much apriciated, i do practice but have varying results, i already have a box i call "blunt and useless" to practice on.

On a side note (as the thread has diverted a bit already) maybe a whloe thread on tool sharpening top tips could be in order.

stuart
 
It would be great to see tips on sharpening drill bits. When a 1" bit costs $80.00 you don't want to spoil it on the grinder. I was thinking of going to the annular cutters. Any comments about these? Stan
 
I like this thread.... I certainly understand the frustration that would come with being unable to sharpen a very basic cutting tool.
But like it or not everyone who uses machine tools needs to be able to do it for themselves.
I remember having, and trying to use one of those general drill sharpeners about 30 years ago. They are a halfway decent way to sharpen drills if it's your only choice. The problem is that to do a really good job with one of them requires quite a bit of practice and attention to detail. About as much as it takes to sharpen a drill by hand.
Sharpening a drill isn't magic, and a drill doesn't have to look exactly like it did when it was new to do the two most important things it must do. 1) it must cut with relative ease, and 2) it needs to not drill an oversize hole. I remember many years ago when I was the tool and cutter grinder at job-shop, there was this old toolmaker who would bring me a new drill and ask me to sharpen it just a little off center because he wanted to drill a hole just a little bit large.
There may be times when you only have one of a certain size drill, and need to drill a blind hole, and then give it a flat bottom, so you need to be able both make a flat bottom drill, and then re-grind back to a normal drill.
When I'm teaching someone how to sharpen a drill I will take modest size drill- say a 1/4 inch, and begin by grinding it completely blunt, and then quickly regrind it to a decent point. I find this takes the mystery out of the whole process, and while it might seem challenging at first, it's a good way to quickly build confidence.
You need a drill point gage, and you need to practice making the drill point centered, and you need to try and keep the angle as close to the same on both sides. The angles don't have to be exactly the same as the drill gage (135 degrees) but they need match each other. Otherwise one flute will do all the work, and you'll only see a chip curling out of one side. Finally the drill needs to have clearance between cutting edge and the heel of the drill. If you're not sure, intentionally sharpen one with too much clearance just to prove you can. It may cut too aggressively and it won't retain it's edge, but it helps establish boundaries.
Sharpen, Drill, Repeat. you'll learn, and you'll feel good about it.
 
Quite a response.......been away for the weekend and just read my emails......

I have developed over the years a technique to grinding drills that stems from machining Titanium and Aluminium Bronze. These materials cannot be pilot drilled as the larger drills drag on the hole being cut and grab the tool. It can mean pushing a 1" drill into solid metal so the web of the point has to be as small as possible. Also deliberately cutting big by dog-legging the cutting edges.


To the purists this may seem like heresy but the point of using a drill is to produce a hole......if it cuts then how can that be bad....if the drill is only cutting on one flute (but cutting all the same) you will still end up with a hole albeit a touch big.


There seems to be an obsession with perfection when grinding drills that is really unnecessary. What is difficult to get are the angles needed, mainly for clearance to allow the cutting edge to dig into the material.


I will take some pictures and re-post here later in the week.


Trevor
 
I have always hand sharpened my drills until recently ,but my eyes are not what they used to be and I can no longer see small drills well enough,so I purchased a DrillDoctor.For me,problem solved.

Ian (seagar).
 
That one operates much like one of the Sterling grinders:

rg-044.jpg

I've used one of those extensively, and they do a nice job, and you can set just about every angle as you need it. I know where one is for sale, but the guy wants too much for it.

I hand sharpen mine, except for the small ones. Can't see any more.
 
Tony Wells said:
That one operates much like one of the Sterling grinders:

rg-044.jpg
Click to expand...

I've always wanted a grinder like this or an end mill style grinder because they seem to be more versatile but are really expensive. A drill doctor has worked well but doesn't shine on the bigger bits. Question on this style:
apavyvy7.jpg
I can see this style would work for sharpening a drill or two but how does a wheel hold up over time? Seems it would be difficult to dress the side of the wheel.
 
Well, in the first place, a regular grinding wheel isn't designed for grinding on the side, so there's a strike against it in my book, but yes, it would work. And it would be difficult to dress. If you notice on the Sterling, there is a small arm above the guard that swings down and holds a diamond nib and can sweep across the face of the wheel. Their wheels are designed for side use though. You would have to build something like that to keep a regular wheel flat on the side.
 
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