Drill Grinding Jig

[VicParticipant @vic]

What do you think?

[bernard towersParticipant @bernardtowers37738]

About what Vic?

[Chris CrewParticipant @chriscrew66644]

Give me a Reliant drill grinding jig any day of the week. It’s a pity they are no longer manufactured and that our Asian cousins have not seen fit to reproduce them, although they do make the inferior Picador type.

[roy entwistleParticipant @royentwistle24699]

I quite agree Chris

Roy

[DiogenesParticipant @diogenes]

Don’t suppose anyone has ever thought of doing a set of drawings for the Reliance, however sketchy..?

 

[Chris CrewParticipant @chriscrew66644]

“Don’t suppose anyone has ever thought of doing a set of drawings for the Reliance, however sketchy..?”

The No.1 Reliance may lend itself to printing in a durable plastic by one of our experts in this field. The metal parts would then be just rods and simple knurled screws. Why the Chinese haven’t picked up on this device is a mystery because I think there would be a market for a reproduction.

[MikeKParticipant @mikek40713]

Hemingway Kits has one, but it appears almost like the Picador.

https://www.hemingwaykits.com/HK1311

 

[Chris CrewParticipant @chriscrew66644]

There’s a Reliance on eBay right now. Ends in 1 1/4 hours today so you better be quick. It’s running at £15 at the moment. They are asking £15 for postage which is a bit steep but if someone gets it for fifteen quid they will still get a bargain, or they could collect if possible. Ends at 16.30pm today. I am watching but not bidding.

[bernard towers]

On bernard towers Said:

About what Vic?

If you reload the page a few times you should see I posted a link to a YouTube Video.

It’s some kind of software glitch.

[Chris Crew]

On Chris Crew Said:

Give me a Reliant drill grinding jig any day of the week. It’s a pity they are no longer manufactured and that our Asian cousins have not seen fit to reproduce them, although they do make the inferior Picador type.

Are they any better than the newer ones? I ask as seeing a review of them the clearance angle changes with bit size, not ideal.

[Chris CrewParticipant @chriscrew66644]

All I can say from experience is that the Reliance produces drill bits that actually cut and the backing-off of the cutting edge can be automatically increased or decreased simply by varying the amount of overhang from the end of the jig which is set by eye. This is because the drill is held at an angle to the grinding wheel and has imparted to it an eccentric rolling motion as the grinding takes place. This is not the case with the Picador type which simply strokes the cutting edge across the wheel and if the rear thumb-wheel is not rotated to advance the bit during grinding there is no backing-off of the cutting edge and the drill will not cut. You need to mark the thumb-wheel on the Picador so it can be returned to its original position for grinding the other edge. It is possible to sharpen bits with a Picador but its very ‘fiddly’ and it takes a little practice to co-ordinate the stroke with the turning of the thumb-wheel. The Reliance is a crudely made device which probably won’t suit those who work to NPL standards but for normal people it provides a quick and easy way of producing a drill bit that will cut first time, every time.

You can see the off-set angle to the axis on this larger No.2 jig and how the bit is rotated on this axis rather than stroked across the wheel, the rolling motion of which automatically generates the backed-off cutting edge.

[Dave WoottonParticipant @davewootton]

There were a short series of articles in Engineering in Miniature a few years ago by Grahame Meek on upgrading the Picador type sharpener. Nothing too complex to make and knowing of the authors other works I would imagine the completed device would work well. I have a feeling the series was titled drill sharpening without tears but may have remembered that wrongly. Another thing I have not got around to!

[Vic]

On Vic Said

[…] I posted a link to a YouTube Video.

It’s some kind of software glitch.

A Bug which I have previously reported, using that handy green button.

… it was duly acknowledged [on Friday 10-May] by the system, but I have no idea how long it might take  to fix.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

A quick grab, whilst Vic’s post was [fleetingly?] visible:

.

.

MichaelG.

 

[Bo’sunParticipant @bosun58570]

Just wondering, but what thoughts are there on using the side of the wheel with the Picador/Reliance style jig?  Yes, I’ve used the side of the wheel for light dressing of HSS lathe tools, but not sure about doing the same with the tool (drill) fixed in position, with somewhat rudimentary control over the tool advance.

[Chris CrewParticipant @chriscrew66644]

“Yes, I’ve used the side of the wheel for light dressing of HSS lathe tools, but not sure about doing the same with the tool (drill) fixed in position, with somewhat rudimentary control over the tool advance.”

I can understand your concerns, but because of the ‘roll’ into the wheel of the cutting edge to be sharpened it does not need to be actually in contact with the wheel, although it must be close before grinding commences. Therefore, you have full control of the pressure being applied to the side of the wheel and if you think it is becoming to great you simply roll back to the starting position slacken off with the rear screw and start again. Or, what I do, simply relieve the rolling pressure because it is in your hands and you are in full control. In practice, despite all the advice, I have been grinding on the side of wheels for the last 50 years with no problem but you must apply ‘common sense’ and care when doing this which I accept, for some people and raw beginners, cannot be guaranteed.

[bernard towersParticipant @bernardtowers37738]

Vic ,with that great big piece of angle and using your fingers I think the vacuum is the least of his worries!!!.

Chris, In line 4 you say (full control of the pressure being applied) which means that both sides of the drill are different whic is why I changed my holders to fit the stent where even grinding is applied to both sides.

[peak4Participant @peak4]

Try a forum search, there’s lots on here about drill sharpening, some of it by me, so a proportion of the info might be dubious. 🙂
Struggling to type at the moment, as I had a cataract done yesterday, so brief comments only.
Reliance works well with practice; I have sizes 1 & 2
Genuine Picador works OK straight from the box, supposed clones mostly use a slightly different geometry and may need modification to get reliable results. Seek out articles by Mr Meek
Hemmingway is a Potts design and should work OK, but personally I struggle to get mine just right. I bought it second hand, and I’m not sure the flute location detent has been made correctly; I’m struggling for a proper diagram for it.

Look up Harold Hall’s website for lots of useful stuff.

Axminster do a useful grinding wheel, which should fit a standard 6″ grinder, wider at the periphery, but with a recess towards the centre, so it fits a normal length spindle; it may not be their recommended use, but the speed rating is OK, it works for me, and is thick enough to allow for dressing.
It should allow access to the side of the wheel for grinding, without worrying about thinning it too much.
References in my previous posts.
Personally I’m set up to use one of those wheels on the Clarkson, with another ready for the Herbert, when I get round to making a wider guard; either of those will allow the feed in, without needing to adjust depth of cut on the jig.

Sealey SMS2008 works OK (ish), but shop around for much cheaper sources.
The original Plasplugs was apparently OK; Not sure about the Lidl/Aldi version.

A few examples here and in the adjacent photos; they used to be in an album on the previous site, with a fuller description.

 

Bill

[duncan webster 1Participant @duncanwebster1]

Sarik hobbies will probably sell you a set of drawings for the ‘Duplex’ drill grinding attachment, which was in ME many moons ago. It looks very much like the Potts.

[Clive FosterParticipant @clivefoster55965]

Adding a few details to what Peak4 say.

1) There are two varieties of the die cast alloy swing across the wheel type. Picador use a vertical shaft requiring the drill edges to be set at “5 to 5″ for correct back-off and good cutting. The alternative version, introduced by General in America (I think), has the shaft angled back away from the wheel to generate back-off with the cutting edge vertical. The axis of the drill on both versions is offset relative to the pivot axis. Both this offset and the projection of the drill point relative to the pivot axis must be correct if sharp edges with good, durable, cutting properties are to result.

Many of the import clones have incorrect offsets and inadequate instructions leading to very poor results. The offset and point projection are inter-related so, with certain limits, variation in one can be compensated by changing the other. It doesn’t help that there is fair bit of mis-information out on the internet concerning set-up. Several folk who should have known better have gotten it wrong. If you need set-up details best to search out the official instructions from Picador or General. Spiralux made a good UK clone of the General and their instructions are also reliable. For a bargain clone. Who knows.

Graham Meek has shown that it’s possible to re-work a badly dimensioned cheap import into a useful device. Something I believed to be impractical due to the difficulty of figuring out exactly where the errors lie. Well done Graham.

The imports are almost invariably of the General, angled shaft, version so the drill projection varies with size. For the Picador device projection is fixed for all sizes but its a short distance and the locating finger less than ideal so there is certain knack involved in use.When a Picador was all I had I would wait until there were several drills needing attention so as to minimise the overall time wasted getting my act together.

The major fundamental weakness of both devices, and to some degree all the ones using a Vee channel holder, is getting both edges exactly the same. The drill needing to be flipped free hand in a not super precise holding device make good judgement essential. The price you pay for something affordable.

 

2) The drill sharpener in the original Plasplugs multisharp kit worked unreasonably well given its cheap plastic nature. Principle of operation was basically that of the General but there was an ingenious device built into it to set the projection correctly and the drill carrier was invertible so no re-setting of the drill. The fixed projection limits the size range over which satisfactory sharpness can be achieved. The edge geometry does change over the range. Only one point angle can be cut. Many of the cheap clones use a diamond grit on steel pressing grinding wheel which is somewhat unsatisfactory. The dimensions on inexpensive copies may be off, reducing the range over which satisfactory sharpness can be achieved.

I looked into replicating the invertible drill carrier and point projection setting devices in larger scale to use on either a Picador or General style jig. Concluded that it could be done but for various geometric and manufacturing reasons 3 sizes of carrier would be desirable to cover the range from 1/8″ to 5/8″. Two could probably manage 3/16″ to 1/2″. All starting to look bit laborious.

3) Then I lucked into the Clarkson sharpener device to go with my T&C grinder. Industrial standard with a 6 jaw chuck to hold the drill and build in flip. Drill sharpening made trivial. Expensive new. One day I shall make a bigger brother to cope with drills larger than 5/8”.

4) For anyone wanting to roll their own the design of the Kaindle BSG-20  https://www.kaindl.de/en/bohrerschleifgerat-bsg-20-2.html   looks to be a neat starting point. Geometrically simple and the comb type V block drill holder is both accurate and inherently invertible. plenty of scope for simplification.

5) 4 facet points are geometrically simpler but you need guided motion with some sort of slide to easily make them accurate enough.

Clive

[noel shelleyParticipant @noelshelley55608]

Replication of the Brierley type drill grinder makes the job easy but it will take a while to make. The Clarkson attachment will make life easier if not a bit costly. By eye is quick and cheap. Noel.

[Clive FosterParticipant @clivefoster55965]

The tricky issue with trying to replicate a Clarkson attachment was always finding a self centring  6 jaw chuck with the long sloped jaws at a sub heart attack price.

The rest is straightforward, albeit chunky, machining if you have the angles and basic dimensions. A good deal of simplification is possible.

I got a Sandu K13-ll direct from China for my proposed enlarged version for around £120 a few years back via E-Bay which seems well up to the required accuracy. If you just want to copy the Clarkson it looks like the 4″ – 100 mm version can be found for under £100 but what customs and VAT will do I don’t know. Much to my surprise mine arrived without additional charges. Seems like they are still about at accessible prices, important to make sure you get the K13-ll with sloped jaws rather than the standard K13.

I really should measure things up and do a drawing for folk.

Clive

[derek hall 1Participant @derekhall1]

I built the “Duplex” designed drill sharpening jig described many, many years ago in the ME (1950’s I think).

I found an old bench grinder and fitted a cup wheel to the grinder rather than use the side of the normal wheel you tend to have fitted to these grinders.

It is a bit of a faff to use and better to have a dedicated session to sharpen a pile of drills rather than just one.

I think the jig is a design based on the reliance/picador style.

I did a mechanical engineering apprenticeship back in the 1970’s and never got the hand of being able to freehand sharpen drills on a bench grinder, I never got consistent results.

[Clive Foster]

On Clive Foster Said:

The tricky issue with trying to replicate a Clarkson attachment was always finding a self centring  6 jaw chuck with the long sloped jaws at a sub heart attack price.

The rest is straightforward, albeit chunky, machining if you have the angles and basic dimensions. A good deal of simplification is possible.

I got a Sandu K13-ll direct from China for my proposed enlarged version for around £120 a few years back via E-Bay which seems well up to the required accuracy. If you just want to copy the Clarkson it looks like the 4″ – 100 mm version can be found for under £100 but what customs and VAT will do I don’t know. Much to my surprise mine arrived without additional charges. Seems like they are still about at accessible prices, important to make sure you get the K13-ll with sloped jaws rather than the standard K13.

I really should measure things up and do a drawing for folk.

Clive

There’s a decent set of photos on The Bedroom Workshop, but I’ve never managed to contact the webmaster.
I have some extra document scans somewhere for his archive
https://bedroom-workshop.com/grinder-clarkson-attachments-dpatlga/0grinder-clarkson-attachments-dpatlga.html

Bill

[Clive FosterParticipant @clivefoster55965]

Bill

Bedroom Workshop is a really useful resource but it seems to have been pretty much abandoned these days. Unsurprising I suppose because one persons enthusiasm can only last so long. I’ve wondered about the morality of scraping the site so the collected information isn’t lost. More so since the threats to the Internet Archive.

Wish that the internet could come up with some way of linking a modest charge for down loading copyrighted material as part of your broadband subscription. Basically extra £5 or £10 a month to download “lots” of Mb. Could fund a proper repository for sites teh creator wishes to disengage from, avoid the paywall nonsense and put a few shekels into the pockets of the many people who have put up useful stuff of their own devising or collation. I often feel guilty using things gleaned from individuals efforts for free when a bit of payment is merited.

Must get round to drawing up my Clarkson attachment. The geometry isn’t properly accessible from pictures.

Clive

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