Drill sharpening, the old timer's way

[martik777]

What carbide boring bar are you using to bore 1/8"? I have trouble with thin bars just flexing and not cutting

 

[DavidR8]

My father taught me how to hand sharpen HSS drills when I was a kid. Pop's been gone for many years now. I did pretty good for many years until my eyesight started downhill. I use a number of small drills, smaller than 1/16 inch sizes that won't fit a Drill Doctor or the commercial drill sharpener. So, those I use hand sharpening with a Dremel tool under a "bench glass". For the larger sizes I now use a Drill Doctor or the commercial machine that will handle the really big drills, Silver & Deming and such up to inch and a half or so.

The Drill Dr works well enough for me, but I have seen a number of comments here, derogatory and worse, to the point that some absolutely refuse to even consider them. All in all, I am still a firm believer in hand sharpening, I've just gotten lazy in my old age.

With this in mind, I have found a useful jig, made by a carpenter on a woodworking site, for grinding drills. He is a woodworker, but his explanation of drills and how to sharpen them is spot on. And his jig is a piece of cake, made out of a scrap piece of plywood. If anyone is considering drill sharpening fixture, I highly recommend watching the video first. If you don't use the jig, opting for something metal, it will still pay off just to see the finer points of what he is covering.

There are two parts, both should be watched. The first is sharpening the drill, the second is building the jig. I cannot give a suitable complement, I just think this guy really has his stuff together. Watch them... ...

Bill Hudson​

Thanks for this Bill, I have one of those General 820 jigs but I cannot seem to get a decent grind out of it. I also have a metric tonne of dull bits that I inherited. Definitely will give this method a try.

 

[Karl_T]

Anyone else an anal engineer here?

OK, we got a 59 degree angle in the XY plane from the grinding face. What angle in the XZ plane is best? 90 degrees is going to leave a heal to remove. He mentions increasing it for a small bit. What would be optimum?

I have a carbide tool bit grinder. the table on this can be set to any angle. i think it would work perfect for drill bit sharpening on the green stone side with a 59 degree wooden V guide.

 

[Lo-Fi]

takes more than a drill guage to properly sharpen a drill. It also takes a very good eye and good knowledge of how a drill works. The intent of this post is to show that it can be done with no more than a scrap of wood

I freehand anything 3mm and above. Learned years ago and never had to suffer blunt drills ever since. Handy skill when out and about with nothing but an offhand grinder available. Once you understand what the angles are supposed to do and how to grind them, you can tailor drills to any job you want too. Very occasionally now I have to go back and dress one of the edges because it's cutting heavier on one flute, but it's rare these days.
Never got on with any of the gizmos or jigs, they take too long for inferior results to my freehand grinding. Sadly never been able to teach anyone else the skill, though.

 

[Tipton1965]

I'm with Lo-Fi, I free hand it all within reason. When I did my apprenticeship back in the 80's everything in the shop was mostly hand ground. I remember going to a job interview at another shop and the foreman handed me an old nasty broken drill bit. He told me to sharpen it on the grinder we were standing next to. I sharpened it and handed it back to him. I told him I even relieved the center since they drill alot of aluminum.....fun stuff.

 

[martik777]

I'm with Lo-Fi, I free hand it all within reason. When I did my apprenticeship back in the 80's everything in the shop was mostly hand ground. I remember going to a job interview at another shop and the foreman handed me an old nasty broken drill bit. He told me to sharpen it on the grinder we were standing next to. I sharpened it and handed it back to him. I told him I even relieved the center since they drill alot of aluminum.....fun stuff.

I had to drill a bunch of 3/8" hole 1.9" deep into 5/8" round 6061 but the bit always gummed up about 1.5". Would relieving the center reduce this? And by this do you mean thinning the web?

 

[Tipton1965]

I had to drill a bunch of 3/8" hole 1.9" deep into 5/8" round 6061 but the bit always gummed up about 1.5". Would relieving the center reduce this? And by this do you mean thinning the web?

I mean taking the flat out of the very tip. We did it alot in the shop so we didn't have to center drill first. It allows the bit to start cutting right away without trying to wander and without center drilling first.