Drill Sharpening.

[Alan .204Participant @alan-204]

Hello chaps after making H Halls grinding rest I thought I would make the jig for sharpening my drill bits but it doesn't seam to matter what or how I do it they do not cut any suggestions, they look right and I have done what it says in the book but I must be doing something wrong and can't see it, any advice would be welcome.

Alan.

[Alan .204Participant @alan-204]

[Chris HeapyParticipant @chrisheapy71135]

Sounds like you don't have enough clearance behind the cutting edge and it is just rubbing..

[Ady1Participant @ady1]

The hardest bit to get right is the centre point area, and this is the most important bit. Do a small hole followed by a bigger hole wherver possible to make life easier for the bigger drill.

I always found that the flutes cut quite easily and the pointy bit held things back

A drill has to be REALLY bad for the flutes not to cut

Edited By Ady1 on 02/06/2013 01:41:55

[Ady1Participant @ady1]

The best advice I can think of is get one you've never touched up and have a really good look at it

Then practice practice practice

I found that a drill press can cover a host of sharpening errors because it applies such high pressure compared to hand drilling steel with a bosch

Once you get it right you can zap through steel with a hand held drill, but it does take a while to "get it"

The main thing to learn is never ever try to force it if it won't cut

Basically… the tip is at right angles to the flutes… which have a bit of relief behind them

If you angle the tip too much it can actually drag the drill into the cut, almost like a self tapping screw

gl

 

Edited By Ady1 on 02/06/2013 03:17:24

Edited By Ady1 on 02/06/2013 03:17:49

[Ady1Participant @ady1]

If you angle the tip too much it can actually drag the drill into the cut, almost like a self tapping screw

You can get away with this with bigger stronger drills and produce cool whirls of swarf, but the teeny ones will grab too much metal and snap, so it's worth knowing any details which control the amount of metal being munched

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Teach yourself to sharpen drills by hand . Practice on a reasonable size drill – say 6 to 8 mm . Keep trying and comparing with a new bought drill and you'll soon master the funny angled twist and push motion needed .

You will then be able to use a grinding jig with more understanding of the set up needed .

Just for interest :

For general purpose drilling many engineers including me sharpen drills by hand as normal practice . Even when I worked directly in industry only the larger and special purpose drills were ever sent to the cutter grinder section for accurate sharpening .

A drill is not a precision sizing tool and the statistical difference in cutting size between a reasonably well hand sharpened drill and a precision ground one is very small in first op drilling and undetectable in second op drilling .

Modern practice in high volume production is to treat drills as expendable items – buy in ready to use and send for recycling when they've done a specified number of holes .

MikeW

Edited By MICHAEL WILLIAMS on 02/06/2013 08:12:55

[dcostaParticipant @dcosta]

Hello Allan, good morning.

I think I had the same or similar problem when I first used my HH tool and cutter grinding rest.

Please see ***LINK*** this thread.

Best regards
Dias Costa

[Clive HartlandParticipant @clivehartland94829]

It looks as if you need to make or invest in a 4 Facet drill grinding jig! This should solve all your problems. To grind a drill by hand, particularly small sizes is difficult without lots of practice, mostly hit and miss.

Clive

[Russell EberhardtParticipant @russelleberhardt48058]

You don't say which drill jig you've made. HH describes one for small drills and one for 4 facet grinding in that book. I have made the 4 facet one and it works fine. Perhaps you should post a close-up picture of the tip of your reground drill?

Russell.

[Harold Hall 1Participant @haroldhall1]

I assume Alan that you are attempting the four facet method, in that case, can I suggest that you look at the explanation of the method on my web site as it describes and illustrates it in more detail than in the book.

This is at – **LINK**

See also the earlier pages in that item that deal with more normal drill sharpening techniques.

These start at – **LINK**

Harold

[Alan .204Participant @alan-204]

I will go back and have another go at it tomorrow if I get chance, have read the reply's and its given me a new lease if you know what I mean, it is the four facet jig I made, for years I have been sharpening free hand and never had much of a problem just gets a bit difficult with the small drills, so thought I would have some ultra sharp drills using the jig ?

Regards Alan.

[Sub MandrelParticipant @submandrel]

Alan,

Try and get a close up of the drill point. It should be easier to make an assessment of a 4-facet point than a conical one from a picture.

Neil

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