drill sharpening jig or dedicated tool

[jon hill 3Participant @jonhill3]

I find sharpening small drills quite tricky by eye on the bench grinder but am reluctent to just buy new ones every time the point goes blunt or I brake the drill.

Is it worth buying/making a bench grinder jig for sharpening twist drill particularly the small drillls of say 3mm and under? Or a dedicated tool to do the same?

[jon hill 3Participant @jonhill3]

sharpening twist drill

[Anonymous]

I've got a Clarkson tap and drill grinding attachment, but never use it for drills. For standard jobbers drills, I just buy new ones as needed. By the time they're blunt they're worn out anyway and not worth sharpening. For drills above 12mm I grind freehand. Life is way too short to waste grinding a drill that might cost a couple of quid. I doubt I spend more than £30 per year on standard jobbers drills.

Andrew

[noel shelleyParticipant @noelshelley55608]

Like Andrew I have commercial drill sharpening equipment but both the Clarkson and brierley only go down 1/8 or 3mm. below this it's not worth the trouble, unless you enjoy doing such tasks. Buy at the right price and a box of 10 dormer,gurhing or the like are less than £5 Good luck. Noel.

[Howard LewisParticipant @howardlewis46836]

The ideal way is to use a cutter grinder and sharpen drills by the four facet method.

SUPERB results once the technique is mastered. Barely need centre drilling and cut like hot knife in butter!

But for a beginner, a passable job can be produced using a Picador type jig.

It is not ideal, but used with care, can suffice until better methods become available..

But there have been various modifications made by model engineers which have improved accuracy

Avoid the gadgets where the drill is located in a plastic holder. A drill,,heated by grinding will melt the plastic and ruin that "guide".

Also, for the integral ones, the power is very low, something akin to a fly on a treadmill!

How do I know? Experience is hard and sometimes an expensive teacher.

Howard

[Howard LewisParticipant @howardlewis46836]

P S

You can make a simple jig. Just a metal block with a Vee slot at an angle of 59 degrees to give the 118 degree point angle.

You then need a simple jig to check that the lip lengths are equal; if the drill is to cut to size. Unequal lip lengths will result in oversize holes.

You can buy a simple gauge to measure lip length so that you can grind them to the correct angle and length.

Howard

[duncan webster 1Participant @duncanwebster1]

Anyone use one of these wishbone. There was an article on making one in either ME or MEW, it's on the to-do list, but so is a lot of other stuff

[Martin KyteParticipant @martinkyte99762]

Under 6mm regard as disposable. I have several sets of drills. a best set (well 2 actually steel and brass). As drills get blunt they are relogated to the DIY category and are also fodder for regrind specials for plastics etc. If you don't have a cast off set you will end up using your good drills for iffy jobs, like using them in battery drills where they will never run true again.

regards Martin

[noel shelleyParticipant @noelshelley55608]

The EXPERT in this field is Derek Brown who has written up in ME. He visited many clubs showing his little diamond pad/ and jig for very small drills. Noel.

[Howard LewisParticipant @howardlewis46836]

The late Giles Parkes beat me to it with using ER collets to hold drills for grinding on a Worden.

DAG Brown really is VERY EXPERT at drill grinding. He has demonstrated the technique on his Qourn at exhibitions,using my abused drills, They cut marvellously.

Somewhere have his drawings for the "manual" honing devices. Another job on the Round Tuit!

Howard

[jon hill 3Participant @jonhill3]

Thanks everyone.

[EmgeeParticipant @emgee]

Jon

If you haven't got one get a decent loupe and sharpen the drills on a fine wheel grinder, you may aquire the expertise required but as said it's probably best to buy new quality drills in such small sizes.

Emgee

[bernard towersParticipant @bernardtowers37738]

I personally like the 4 facet method as it almost makes centre drills redundant. I made a couple of jigs to sharpen 3 to 6mm and another one to take up to 13 mm. The smaller ones I do on a DAG Brown jig. The two jigs for the cutter grinder are an adaption from article in MEW by Roland Gyllander from Sweden. 1995 I believe.

[Clive FosterParticipant @clivefoster55965]

Reluctant though I am to cross swords (keyboards!) with Andrew Johnston I strongly disagree with his view that the Clarkson Drill grinder accessory is of little utility.

As I do a fair bit of fix-it work my drills are, perhaps, more at risk than his from the 'Orrible Metals Company alloys like "Drill Muncher", "Super Hardinium", and "Inclusion Rich" or similar products from other sources.

My Clarkson attachment is permanently set up and in very regular use.

If there is there is slightest question as to whether a drill is still really sharp it goes on the Clarkson. Takes about 90 seconds from drill box to sharp to chucked up on the machine. Having really sharp drills on tap all the time does make life easier and makes for better work.

I used to use Andrews method of buying new drills when the old ones were blunt. Which wasn't stupid expensive, even at pre millennium prices. But I now know that much of the time the drills, although still sharp and working decently, were not giving optimum performance.

For the home shop person the big problem with the buying strategy is always what happens when you kill a drill on Friday evening and the engineering tooling shops don't open until Monday. Assuming you can get away from work during shop hours! Can't get a 9.3 mm drill from B&Q on Sunday morning. Or maybe a week to mail order, as was back then. Couple of days now from the switched on suppliers now, sometimes better, but still a wait.

I had a Picador for sharpening when buying wasn't going to meet the schedule. Effective but a considerable faff and so slow taking into account time wasted remembering how to do things after 6 or more months since last time.

If its going to be useful a drill sharpener has to be fast, effective and right first time every time. Which basically rules out all of the jigs unless you follow Graham Meek and do a proper re-engineering. Although the cheapy Plasplugs Multisharp thing was, in its original incarnation at least, unreasonably good.

For a Clarkson the technique is put drill in 6 jaw chuck with 1/2" projection and edge level. Bring up to touch the wheel, swing lever up, feed a touch more, start machine waggle the lever until it stops sparking. Swing up, rotate spindle by 180° (really hefty positive stop), repeat waggle and job done. Right every time.

Nothing else remotely home shop suitable comes close in speed and reliability.

My opinion is that anything less is flat out not good enough and won't be used. The better 4 facet set ups can come close tho'.

Baby drills of course are bin and buy, packs of 5 or 10 usually.

Clive

[Anonymous]

Posted by Clive Foster on 08/01/2022 19:53:52:

…..disagree with his view that the Clarkson Drill grinder accessory is of little utility.

Swords at the ready!

That's not what I said; I don't use it for drill grinding, not saying it was of no utility. It's my personal preference to buy rather than grind. By the time my jobbers drills need replacing they tend to be rather a mess. I use the Clarkson attachment for grinding the lead on taps, both commercial and home made:

Andrew

[Clive FosterParticipant @clivefoster55965]

Ooops!

Sorry Andrew finger trouble.

Meant to write "little utility for drill grinding" but the "for drill grinding bit" fell off twixt brain and keyboard.

One day I shall try the tap lead grinding feature. Slowly getting a collection of won't cut ones.

Must try harder when proof reading.

Clive

[Anonymous]

Posted by Clive Foster on 08/01/2022 21:35:5

Sorry Andrew finger trouble

No need to apologise; can't imagine we'll be duelling at dawn!

Andrew

[noel shelleyParticipant @noelshelley55608]

Like you Clive, I cannot tolerate blunt drills, so small ones in the bid & buy new.

For not much more than the price of a Clarkson DP&TL attachment on the usual place I bought a Brierley drill sharpening machine That makes the Clarkson attachment look very slow, it will do most forms of point and will do up to 1.25"Dia, twice the size a Clarkson can handle. Noel.

[BazyleParticipant @bazyle]

If anyone is throwing drills away if just blunt (as opposed to damaged) please consider giving them to your local men't shed who will have people who are not in a hurry and can spend a day working through a box full as occupational therapy.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Jon Hill 3, this free Drill Sharpening Jig plan might interest you, although the construction notes are in MEW 17.

Regards Nick.

[Mike HurleyParticipant @mikehurley60381]

Re small drill sharpening – I inherited these two items from my late brother (he was a competent model engineer), and I assume they are for sharpening small drills. OK insert in V, set projection to give appropriate angle and rub on oilstone / diamond lap. Rotate 180 & repeat.

But that will only give you flat cutting edges with no relief surely? Is there a nack to doing this? I have seen articles on units such as the ' butterfly ' jig that allows you to tilt slightly to give the relief, but these do not seem to permit that easily.

Also, any obvious reason why 2 different heights?

( I meant to put a rule in the photo but forget. They are both around 20 – 25mm across )

I may be barking up the wrong tree totally, but if these are useful they would assist me greatly – so any input most gratefully received. Regards Mike

Edited By Mike Hurley on 09/01/2022 10:35:20

[Rod RenshawParticipant @rodrenshaw28584]

I wonder if the items that Mike has inherited are intended for sharpening screwdrivers or gravers?

I have an original "Wishbone" sharpener ( is the buttterfly one similar?) which I bought many years ago. It does work for small (sub 3mm) drills though it takes time and practice. The original "whetstone" was too coarse, in my view, and I use a fine diamond bench stone instead. The original loupe was rubbish and had to be replaced, so I don't have very much of the original kit. I tend to buy new drills now because time is short and the economics seem to have changed.

Rod

[bernard towersParticipant @bernardtowers37738]

I would imagine that if the drill bit was projecting the same amount in each jig you would be able to get 4 facets,

[Mark RandParticipant @markrand96270]

I use a Picador Fig 9 jig for drill sharpening using the surface grinder (haven't been able to find the larger model). I've got a Darex drill Doctor 750X, but it can produce strange results.

I have been transcribing the Duplex drill sharpening jig (ME September 1951 and onwards) into an Alibre model at double scale to work with drills up to 1" diameter and it's on the list of things to make.

[Mike HurleyParticipant @mikehurley60381]

Posted by bernard towers on 09/01/2022 12:41:49:

I would imagine that if the drill bit was projecting the same amount in each jig you would be able to get 4 facets,

Hadn't thought of that! Thanks fot the suggestion, i'll give it a try & report back.

ROD: Thanks for the comments. I have seen both terms used for the same physical unit.

It's unlikely that these were used for anything other than drills (but not impossible I suppose) as I know he did a lot of small hole drilling – he'd built many fine models over the years and was half way through a model of the Agenoria when he passed away. There's an awful lot of rivet holes in that one !

Take care. All the best Mike

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