Drill sharpening

[Guest asmol]

Hello all, i have a heap of metal drills that are blunt and need sharpening. I purchased a $40 attachment from Bunnings that goes on the end of a drill and its f'ning useless.

 

I will spend the money to get a proper tool, any ideas on what to get ?

 

and, no i dont want to learn how to do it by hand, my eyes and the shakes would stop me from doing this properly. Any ideas on what to get are appreciated. Thanks

 

 

[Cosmick]

Googled Drill Sharpener, Try ---

 

http://www.drill-doctor.com.au

 

 

[Guest asmol]

Thanks Mike, I looked at these but dont want to purchase another one unless recommended by someone on the group who has used one.

 

 

[Ultralights]

i have used the drill doctor above, does an ok job, but the bits will never be as sharp as a new drill bit...

 

 

[Bubbleboy]

I have one of these and it does a pretty good job on drills from 3mm up.

 

http://www.bunnings.com.au/ozito-65w-multi-function-sharpener_p6290088

 

Scotty

 

 

[SDQDI]

i have used the drill doctor above, does an ok job, but the bits will never be as sharp as a new drill bit...

it is extremely rare to find a drill set that doesn't need one or two drills touched up to start with, even the better quality sets from Sutton ect. Even if hand sharpening them isn't your thing Asmol I would recommend seeking a good fitter or boilermaker and getting them to show and explain the technique to you as there will be little tips that will help even if you are using a gadget. In my limited experience (farmer by birth, did a few years of tafe welding) I have learnt that drills are one tool that skimping on quality will make more work for you down the track.

 

 

[Ultralights]

also, make sure you have the correct type of bits, silver bits are usually for wood, plastics, and soft metals like copper and commercial aluminium . High speed steel are better for aircraft harder aluminium alloys, and soft steels, but wont last long on steel. the best would be Cobalt drills, usually a dark yellow colour. work well and last long with aluminium, but will get through hard steels and titanium. even steel fasteners such as bolts etc.

 

 

[Guest ozzie]

Many different types of cuts you can put on a drill face. If you are drilling sheet then i recommend that you learn how to put a sheet cut on the bit especially number drill bits for clearance holes.

 

Another way to do it is find a first year apprentice fitter or toolmaker and get them to do it. Or stock up on double ended drill bits.

 

I have yet to find one of those drill sharpeners to do a decent job.

 

 

[mothra]

My younger brother was apprenticed as a fitter and turner and taught me to hand shapen drills decades ago, there are some details to get right and you'll butcher a few on the way but its a skill worth having.

 

Bigger diameter drills are easier to learn on and give you a chance to recover a botched job.

 

You can end up with some minor variance in diameter if you are off a bit so I'd always recommend a new drill for precision work, its not that expensive in the end .

 

 

[geoffreywh]

where do you live? I'm sure there is a ( retired ?) fitter/turner/machinist that will throw an hour or two your way?

 

 

[kgwilson]

Drill sharpeners are pretty much a waste of time in my experience but it does take a lot of practice to get right. All you need is a bench grinder with a fine grit stone wheel and 2 hex nuts. Get a bunch of old drills to practice with. The angle between the 2 nuts when placed together on the bench is the correct angle for most drill bits when putting the drill tip between the 2 nuts. Once you have perfected this angle then the angle of the cutting edge relative to the drill twist groove is how much cut you will get. Too little and it wont cut & too much will blunt it quickly especially if the material is hard steel.

 

There is an old bloke I know, a retired fitter/turner who can just about sharpen them blindfold and to perfection. I sharpen my own but if I want them perfect I give them to him.

 

 

[tillmanr]

If your angle to the stone is correct, the cutting edge is a straight line. If the drill is closer to perpendicular to the grinding face the edge will be concave. Too shallow an angle gives a convex rounded cutting edge. The back angle and pressure (feed) on the drill determines the cut.

 

 

[sain]

there are some really good vids on youtube regarding drill sharpening.

 

 

[M61A1]

I have used the "Drill Doctor" with reasonable success. It is ideal that you sharpen the drills as they dull, if you've chipped out the corners badly or burnt the tip, just get new ones.