drill bit sharpeners

[woody paul]

Slightly dulled small drills can be sharpened on some emery paper on  a flat surface done it on jobs when no grinder on job. 

[Baldbloke]

I tried the Lidl one and it was Ok to start with but not working so well now. Not changed the stone yet so that could be the problem but if it is the stone it's not lasted long. Larger bits I do free hand on the bench grinder but it's a tricky game with smaller bits.

It’s a matter of getting the cutting edge being higher than the relief. Once you’ve mastered that on a grinding wheel you have a usable bit until it’s too short to use.

Ignoring the depth control gauge on a chainsaw chain look at the side on profile of a chain and you can see the cutting edge is proud of the relief. It’s the same with a drill bit. A badly sharpened drill bit often doesn’t have the cutting edge above the other material so the bit heats the work rather than making the desired hole. Another fault is doing too much grinding and producing too much heat. Then the bit loses its temper and it’s knackered.

Small grinds with a finishing twist to ensure the cutting edge is proudest[emoji1303]

 

I have a couple of mates that bring boxes of drills for me to sharpen on a regular basis.[emoji3]

[doobin]

The heat is a real issue. A cbn wheel makes so much difference. 
 

to be frank, you’re wasting your time trying to learn to sharpen on a cheapy grinder with a grey wheel. You’ll need to dress the wheel every twenty seconds and it’ll still get too hot and your bits will blue slightly then chip when you try to use them.  Invest in a decent wheel- ceramic grain wheels are not that pricey and a big step up. But cbn makes life easy. 

[doobin]

And if you don’t have a drill gauge get one and learn to use it before you start! 

[Canal Navvy]

7 hours ago, doobin said:

And if you don’t have a drill gauge get one and learn to use it before you start! 

Nuts......., a pair of them ?

[Macpherson]

18 hours ago, doobin said:

to be frank, you’re wasting your time trying to learn to sharpen on a cheapy grinder with a grey wheel. You’ll need to dress the wheel every twenty seconds and it’ll still get too hot and your bits will blue slightly then chip when you try to use them. 

I've used a ordinary grinder for this purpose all my life, you should have a pot of water next to it and quench after a couple of touches or when you notice the bit getting straw coloured.....as for dressing the stone.....if it's for sharpening only use it for that and it'll only need dressed occasionally.

 

[Stubby]

1 hour ago, Macpherson said:

I've used a ordinary grinder for this purpose all my life, you should have a pot of water next to it and quench after a couple of touches or when you notice the bit getting straw coloured.....as for dressing the stone.....if it's for sharpening only use it for that and it'll only need dressed occasionally.

 

You should have a " star wheel " dresser or better still a diamond on a stick .

[doobin]

Nothing will touch cbn for a clean cool grind. Stubby, pop down my yard for a go. You’ll be a convert.

[Will C]

15 hours ago, Canal Navvy said:

Nuts......., a pair of them ?

That’s how I was shown to get the angle, ive got a pair welded together next to the grinder ?

[doobin]

42 minutes ago, Will C said:

That’s how I was shown to get the angle, ive got a pair welded together next to the grinder ?

That’s a good start, but a a drill gauge is cheap and allows you to easily check angles and more importantly, each flute length. 
 

also two nuts give you 120 degrees. 135 degrees is a more useful angle for metal work. Most quality cobalt bits come at 135 from the factory.