# Drill sharpening jig



## firebird (Nov 23, 2011)

Hi

Has anybody made a simple drill sharpening jig? I'd like to make something that I can use on my disc sander sooner than the grindstone. Any ideas welcome.

Cheers

Rich


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## ShedBoy (Nov 23, 2011)

I assume you know a bit about drill point geometry already. Try this site lots of good info

http://www.gadgetbuilder.com/DrillSharp.html

I have an inexpensive drill bit sharpener as described at the bottom of the page which seems to work okay once you know what is happening and what causes what. Here is a another page with some good ideas.

http://www.instructables.com/id/Sharpen-Your-Drill-Bits/?ALLSTEPS

If you look through the rplies the is a different way to mount it which would be better. I am sure you will open a can of worms with this question. I am looking forward to the answers.
Brock


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## ShedBoy (Nov 23, 2011)

Here is one for small drillls from the model engineering website.

http://modelengineeringwebsite.com/Small_drills.html

Brock


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## rake60 (Nov 23, 2011)

I worked with guys who could hand grind a drill bit perfectly every time.

I could never do that, so they were all very dear friends! 

The problem with a drill sharpening jig is it doesn't really grind the relief 
from the cutting edge. 

Bits sharpened in a jig will drill but the cutting edge will often have zero or
even negative relief. They don't cut well and burn up quickly.

This isn't a plug for Drill Doctor, but it explains it better than I can.

[ame]http://www.youtube.com/watch?v=K90WlpZK_MI[/ame]

Rick


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## Tin Falcon (Nov 23, 2011)

I learned how to hand sharpen . I do I will say a decent job at it. I also have a drill doctor. It also takes some practice and feel but much more consistent than by hand. There had been an ongoing discussion about the drill doctor in another thread, so will not get too involved here. 
Tin


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## firebird (Nov 24, 2011)

Hi

Thanks for all the replies so far. Thanks for the links Brock. 

I have a disc sander in my wood work shop which I use for shaping wood (obviously) but also for grinding chisels, screw drivers, plane irons in fact pretty much anything I can throw at it. One of the best bits of kit I have ever made. I'm currently building a 8 inch version for the metalwork shop. Being able to grind on a flat surface is an advantage I find. I'm not keen on using the side face of a grinding wheel. I have sharpened some of my larger drills by hand on the disc sander with reasonable results but not as accurate as I would like.

I have seen the drill doctor before which looks to be a nice tool but not within my budget at the moment.

It seems there is a bit more to drill sharpening than first meets the eye. 

My thoughts are if I can hold the drill bit at 59° to the disc in a jig of some sort then turn it I would at least be able to get a better more accurate grind. What do you think.

Cheers

Rich


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## ShedBoy (Nov 24, 2011)

I met an old chap who use to sharpen his drills in that way with on addition, he ground the negative relief after the twisting part. This left no chisel point but a cone point, it worked okay for wood, don't know how it would go with steel but I think there would not be enough strength in the point. Drill point geomtry is the key.

Brock


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## tel (Nov 24, 2011)

Most of my drill sharpening is done freehand on the home made 7" disk sander as well - they do a good job. I am, however, having made the Harold Hall grinding table, looking to use that with the smaller sizes


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## Tin Falcon (Nov 24, 2011)

how about one of these
http://www.generaltools.com/825--ORIGINAL-DRILL-GRINDING-ATTACHMENT_p_213.html
Tin


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## ShedBoy (Nov 24, 2011)

That is the type I run, takes a bit to set up right but I have good results with it as long as it is mounted at the 12 oclock position on the side of the wheel. This way it grinds perpendicular to the cutting edge and makes for a strong edge, if you mount it at 9 oclock the cutting edge chips real easy. Good cheap tool and if you look you will see them alot in the background of posts so they are used. I got a big fluro magnifying desk lamp to help with set up of small drills. They work good on discs and belts too. 

Brock


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## tel (Nov 24, 2011)

Yeah, they work well, but are a real fiddle to set up - I've had one for many years, but rarely bother with it.


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## Tin Falcon (Nov 24, 2011)

I have one of the general jigs IIRC I paid like $ 5 us for it at a Habitat for humanity restore (thrift Shop ) it was New in box condition. I still have it still in the box never used. 
The drill doctor gets some use. 
I never liked the idea of side of wheel grinding maybe A mount for the disk sander another to do. 
Tin


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