Drill Sharpening Jigs – Advice please.

[John ShepherdParticipant @johnshepherd38883]

Armed with a bit of extra knowledge thanks to Clive I took my cheap swing jig out of the scrap bin and spent an hour trying various combinations of drill projection and lip angle and no way could I get a satisfactory clearance angle – whatever I did it was always too large.

 

I was just about to give up when I noticed that the v grove for the drill is offset from the pivot by about 4mm to the right (looking from the back).

 

By packing the joint between the main body and the pivot to bring the centre of the pivot and the bottom of the V in line I found I could get something like the proper geometry by rotating the lip about 10 deg from vertical and with the recommended 1/2 dia projection.

 

Incidentally, the base of the jig is angled forward by about 7.5 deg  as Clive mentioned and it looks as if this has not been taken into account when calibrating the drill point angle because when set to 59 deg it is out by about that amount.

 

It would be interesting to hear from anyone with the original Picador or any other variant  if the v is in line with the pivot. (BTW my jig was from Machine Mart but Im sure it is simiar to those from other suppliers)

 

My jig will be going back in the bin but I am now thinking of making my own clone based on what I have found. Who knows perhaps an article for MEW? 

[John Stevenson 1Participant @johnstevenson1]

What would be nice is if someone did a copy of the Christen 03 -10 drill grinder as an article

These grind from 0.3mm to 6.35 mm but can be adapted to 10mm capacity, they only grind 4 facet but can thin.

 

Are you sitting down ?

 

These cost about £9,000  and they fit in a shoe box, they still make them so there must be a demand for them.

 

I have one and use it all the while. I make some parts that have literally 1,000’s of holes in them from 2.5mm to 3mm and none of the off the shelf drill will stand up to this work.

I buy good quality Guhring drills and grind them from new into 4 facet drills using the inbuilt microscope.

 

An off the shelf drill will do about 700 holes before the web starts to break down, same drill reground to 4 facet will do 2,800.

 

It’s not about saving the cost of a drill, it’s about wasting a part if the drill breaks and the lost time.

 

John S.

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by John Shepherd 1 on 24/09/2010 09:25:54:

Andrew

Thanks

 

Judging from the comments in the link, that looks like option 1 out then – I am not totally surprised.

 I used to own a Drill Doctor – unfortunately, its bedside manner left a lot to be desired. Admittedly I bought mine s/h, but it was in decent condition & had the instructional video to show you how easy it is, but I could never persuade it to give even acceptable results let alone good results. It sat on my bench taking up space for a couple of years before it went back on Ebay.

 

I’m currently building a Worden; will see if the drill sharpening jig for that is up to snuff.

Regards,

Tony

[Axel BentellParticipant @axelbentell]

Sparey´s The amateurs lathe has a good chapter on drills.

[NilochParticipant @niloch]

What about this?

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Niloch on 22/10/2010 17:13:37:
What about this?

 Looks good, but ~ 175 squid & I believe it is designed to fit a Tormek grinder – there’s reference in the Q&A about the grinding being water cooled. No doubt you could cobble it onto something else though.

 

Not a lot there that you couldn’t build yourself, of course, including the nifty one-size-fits-all drill clamp.

 

Regards,

Tony

[chris stephensParticipant @chrisstephens63393]

Hi Niloch,

Saw an advert for one of those a few weeks ago, have you seen the price? 

chriStephens 

[John ShepherdParticipant @johnshepherd38883]

Saw this in my search for drill sharpeners but I have already got 4 a facet jig that works reasonbly well thanks to a design by Harold Hall.

 

Leaning toward a Potts or similar for conventional sharpening but still to make up my mind.

Thanks for all the replies and if anyone has anything to add about the Potts I would be interested.

 

John Shepherd

[Clive FosterParticipant @clivefoster55965]

I’m sorry that John hasn’t been able to report complete success.

Looks like I shall have to have a rummage for the analysis on drill points and swing jigs I started ages back to see if it can be made “ordinary guy friendly” with some numbers and plots to show what’s going on.  My recollection is that qualitatively its clear what happens but putting numbers in and comparing results to the real thing is less than easy.  However in the intervening couple of decades some ideas for different approaches have surfaced so, once I get rid of this stinkin cold, we shall see if anything publishable can be produced.  Given the number of swinging jig designs that exist and can be made to work by dint of sufficient effort the basic principle clearly isn’t rocket science.  But given that every design seems to cause problems for even the most instruction diligent users it looks as if the geometrical analysis has been less than exhaustive.

 

Despite the impressions given in certain quarters four facets aren’t the be-all and end all either.  Although very effective in machine guided situations they tend to be unstable in hand held use.  Think of a masonry drill.  These are basically 4 facet geometry but wander all over the shop given half a chance. Functionally 4 facets are spade drills.  Even on an industrial scale 4 facets are easier so cone points wouldn’t be standard without good reason.

 

 Clive

[Anonymous]

Hmmmm, the Tormek looks interesting, but it’s not cheap. Does anybody have experience of using one of these devices?

 

Regards,

 

Andrew

[Billy MillsParticipant @billymills]

The Tormek jig and their grinderwould take you into £400 region depending on the grinder chosen. That is a lot of drills. Having said that, I am a great fan of Tormek, their slow wet grinder is the fastest way of getting brilliantly sharp edges on edge tools time and time again. The grinder is a large wide stone wheel running around 90-120 rpm, the stone is immersed in a water bath at the botom. The bare stone is about 220 grit but with a re-grading stone you can convert the grade to 1000 grit.

 

There is a round bar mounted parallel with the stone axis along which all of the jigs are mounted so it is easy to remount a tool for resharpening. The stone is dressed with a diamond tool referenced to the bar. All of the jigs from Tormek are very well designed and easy to use alloy castings while their use is described in a book and DVD with current updates on the website! The system includes  leather honing wheels as well.  Jet make simular parts at lower prices.

 

Don’t have the drill jig but can say that wet grinding is very effective and completly avoids the risk of destroying edge temper. The other key detail is that the edges have much greater smoothness than from a 36 or 60 grit dry wheel so cut  with less force and better surface finish.

Regards,

Alan

[Billy MillsParticipant @billymills]

Had a look for  John’s Christen machine, found the spares and operating instructions at :-

http://www.christendrillgrinder.com/manualNOV2009.pdf. It is not vastly more complex than many T & C grinders but has a 20x microscope for aligning the drill. The operating instructions and the parts drawings might give the keen all they need!

 

One of the interesting details is that this is a 0.5-6mm drill sharpner i.e. it works in the range where the simpler adaptors fall off. But £9,000 buys you a lifetime supply of drills and some!

 

Regards,

Alan.

[Chris KellandParticipant @chriskelland71558]

Interesting.

 

It seems that the Potts drill grinding jig is based on an article by L. A. Van Royen which appeared in the Model Engineer dated 14 August 1913.

 

Fast forward to August 2008 and Harold Hall wrote in MEW on sharpening twist drills and mentioned the Reliance drill grinding jig which is very similar to the Potts. From his article it seems that the modern (cheap) drill grinding jig works in a similar way.

 

Ian Bradley’s book on The Grinding Machine has further information on swing grinding jigs, the Patts and also one by Van Royen.

 

Following Harold Halls description in another article I have used an off hand grinder with a cup wheel and enlarged safety guard in conjunction  with a cheap drill grinding jig and get quite satisfactory results. I feel that the secret is to get the drill projection correct in relation to the diameter of the drill. I feel this method is viable once a little practice with old drills has taken place.

For drills below 1/8 inch I use a butterfly jig for sharpening.

 

 

 

Regards,

 

 

Chris.

 

 

[chris stephensParticipant @chrisstephens63393]

Hi Chris,

 The Reliance jig has little or no similarity to the Potts, Van Royen or Duplex one. It is much more akin to the Picador or one of its cheap imported copies.  The three mentioned all have a means of measuring the drill diameter, which automatically adjusts the grind to suit. The Reliance has no such feature, but despite this can be made to work by measuring the drill, multiplying by a factor of either 3 or 5 (sorry cant remember which its been long time since I used mine and i seem to remember the instructions were wrong anyhow) and adjusting to projection to suit.

The big draw back of the Reliance is that you need to align the cutting lip with a scribed line on the jig, this is not always easy if your eyesight is below par, as the distance between the two can be relatively large.

Hope this clarifies things.

chriStephens 

[Paul BoscottParticipant @paulboscott25817]

 This is just an idea for discussion, as I have not yet the skill or understanding to complete the task

The idea if possible would easily off set the cost of a machine if some of the prices mentioned are a viable option or at least help to justify the cost.

As small CNC mills / lathes are now becoming more available in the Model Engineering environment would it be possible to use a small diamond wheel and write a G-code program to sharpen a drill.

The size of the drill and the angle could be entered as data the datum could be the end of the drill the centre line of the quill or headstock is already known by the machine.

As I am writing this I can see that the position of the flutes would also have to be located.

Has anyone any further thoughts on this? Is already done?

[Howard JonesParticipant @howardjones35282]

the photo is my drill sharpening jig, one of my first model engineering projects at the suggestion of a maestro.

there is a little V notch across the thing which locates the drill. you eyeball the angle of the drill usually by matching the existing sharpening. the whole thing is then just stroked along an oiled fine slipstone. it achieves absolutely regular drill ends.

I made mine on my shaper from SAE4140 which my maestro friend then hardened and nitrided for me.

It is a model engineer published design though craft disease hits me for the details.

I think it was a Bradley design. works a treat.

that is a 1/16″ drill in it.

[korbyParticipant @korby]

In the current edition of Woodworker is a review of a drill sharpening att. for the Tormek grinder. This is a wetstone grinder for wood tools. Thing is a picture of a drill sharpened on it shows unequal facets. The att costs £170 and the grinder £300.

Seems that woodies have very deep pockets compared to us metal bashers.

[Peter GainParticipant @petergain89847]

I am surprised to note that no-one in this thread has mentioned the Proxxon drill sharpener. I raised the question of how to get the thing to work in a thread in Jan this year. Never did get any definitive answers. I now use the Harold Hall sharpening rest. The Proxxon has gone back under the bench. The Proxxon brand has been refered to in another thread. Use caution when purchasing this “make”. Their more expensive items are EU sourced, but the cheaper products appear to be Far Eastern. “Engineered in Germany” is NOT the same as “Made in Germany”!

Peter Gain.

 

 

 

[keithmartParticipant @keithmart]

Hi

I have just been to our local Lidle and purchased a drill grinder for £19:99. It will sharpen drills from 3 to 10mm and works well.

It also comes with a set of TIN drills in half mm steps, plus two spare grindstones.

I ground a very blunt 10mm drill and drilled through a scrap piece of steel with no problems.

regards

Keith

Leeds UK

[Martin Walsh 1Participant @martinwalsh1]

I use the proxxon drill sharpener very pleased with it

works well

 

it grinds drill from 3 to 13 mm but you can get adaptors

for below 3mm

 

Best Wishes Martin

 

[alan frostParticipant @alanfrost17805]

Just to add two penny worth I have owned most of the cheapo sharpening jigs and find with care they can give a good result,including the swing jigs. I had never tried free hand sharpening as I’d read so many threads on how difficult it could be but recently I was lucky enough to get a visit to my workshop when drilling lots of big holes in mild steel (upgrading a trailer to take a couple of tons) by a retired toolmaker. He gave me a demo of freehand sharpening including very small drills, four facet sharpening etc.

A demo with a chance to then try it yourself is worth thousands of words and within literally five minutes I was producing very acceptable results with the promise “The more you do the better you’ll get “.

The ability to sharpen any blunt drill within a few seconds without setting up jigs is not as difficult as many would have us believe especially if you can get a demo from an expert and is such a convenient skill,

It became even easier once I cleaned up my wheel with a dressing stick and used a pinchuck and eye loup for small drills. I’m not claiming my sharpened drills cut dead to size (how often does that matter ?) but I keep a good set for that which I use rarely enough that they don’t need much sharpening. They don’t cut dead to size anyway.The ones I now sharpen freehand cut really well and altho I have n’t measured anything , pretty well to size.

I have read somel none positive reports of the drill doctor.

Edited By alan frost on 22/08/2011 14:41:18

[John HaineParticipant @johnhaine32865]

There was an article in an early MEW on a simple jig for sharpening small drills to 4 facets using a diamond plate – can’t remember the author I’m afraid. It struck me as a very nice design and is on the mental “to make” list (probably at about number 3277!).

[chris stephensParticipant @chrisstephens63393]

Hi John,

Long time no see. The jig you are talking about is probably the DAG Brown one, or at least it would be if you are talking bot ME not MEW. This jig is indeed a very elegant solution to small drill sharpening and I can heartily recommend it, as I am sure a very large number of ME readers would agree. This is because I believe his jig is the most reproduced tooling of any that has been published in the magazine.

 

By a strange quirk of fate I am at the moment making an up dated version, well an almost complete re-design, that is showing some promise and is certainly easier to use than the original, as it takes out some of the guess work from getting the facets equal.

As the original was so popular, I might consider doing a write up, but I would have to get the go-ahead from Derek first, partly because it is his original idea and partly to find out if he still does the diamond plate. Depending on the availability of his plate depends on whether I design the up date to take his plate or whether to design it to take readily available commercial ones.

 

For those who don’t know what I am talking about, take a look at;

http://www.gadgetbuilder.com/DrillSharp.html#Four_Facet

chriStephens

[NJHParticipant @njh]

Taking Keith’s tip I too purchased the Lidl drill sharpener. With a certain amount of scepticism, born of poor experience in the past of other patent devices, I gave it a try on a 3mm, 4,2mm and 7mm which had been languishing in my ” Old Drills” drawer.

BINGO – it works! Comes fitted with one specially shaped stone and two spares so hopefully it should sharpen quite a few drills.

Thanks for the tip Keith.

 

Regards

 

Norman

[Dave TointonParticipant @davetointon92281]

G’Day John,

The best drill sharpener I have come across is the simple hand and eye offhand grinder technique. It takes no time to set up, is cheap and almost always results in a good job. It merely takes a bit of practice to perfect the sort of swooping motion of the right hand and one can see immediately if it is right simply by looking at the drill.

Regards

Dave Tointon

 

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