Four facet drill grinding.

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Four facet drill grinding.

This topic has 25 replies, 14 voices, and was last updated 8 September 2022 at 21:10 by bernard towers.

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26 April 2021 at 16:59 #541694
alan ord 2
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@alanord2
Help!! I am trying to find an article on 4 facet drill sharpening published in either ME, MEW or EIM. I'm sure I read an article in the last few years. I have tried searching the on line index of published articles, using various combinations for the search without success. There are older articles pre 2008 but I'm sure there was a more recent article. Does anybody know what the mag and issue or date was. I'm pretty sure I'm not suffering from the onset of dementia. At least I hope not!!!!!

Alan.
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26 April 2021 at 16:59 #28126
alan ord 2
Participant
@alanord2
26 April 2021 at 17:13 #541699
Alain Foote
Participant
@alainfoote90915
DAG Brown Model Engineer 1994 no. 3968 is a good starting point.
26 April 2021 at 17:14 #541700
bernard towers
Participant
@bernardtowers37738
DAG Brown has done articles in the past but there is one in ME Jan/Feb 1995 by Roland Gyllander from Sweden. i have made his jig but found it susceptible to variable hand pressure so have adapted it to fit directly on the T and C table removing the variable hand pressure problem. I have made a start on a article for MEW about the adaption but not finished yet! and sometimes think people have had enough of four facet articles. if interested drop me a PM
26 April 2021 at 17:17 #541704
alan ord 2
Participant
@alanord2
Thanks Alain, I did see that ref in the online index and I do have the mag. But I'm sure there was a more recent article published in the last few years. If all else fails I will have to do it the hard way and do a manual search.

Alan.
26 April 2021 at 17:18 #541705
Martin Kyte
Participant
@martinkyte99762
Here is some info for starters.

**LINK**

regards Martin
26 April 2021 at 17:18 #541706
Journeyman
Participant
@journeyman
There is an article by Gadget Builder in HSM (Home Shop Machinist) try this link to his pages there is a whole load of info on drill grinding , jigs and some of the theory. Also a powered 4-facet grinder/jig ** Drill Sharpening **

John
26 April 2021 at 17:55 #541715
alan ord 2
Participant
@alanord2
I've found it.

ME Vol 215 issue 4513 2015 by D.A.G. Brown. The reason I could not find it using the on line index was because the title of the article is "Further Developments in Drill Sharpening"

Dementia not just yet!!!!

Thanks to all for your advice.

Alan.
26 April 2021 at 18:11 #541717
Michael Gilligan
Participant
@michaelgilligan61133
Well-found, Alan

A collection of data becomes information when you properly index it.

MichaelG.
26 April 2021 at 18:58 #541728
Howard Lewis
Participant
@howardlewis46836
D A G is very expert at four facet drill grinding on his Quorn.

Four facet ground drills cut extremely well and a centre drill for starting is not obligatory.

Keeping the lip lengths equal is the secret to having accurately sized holes.

You are effectively grinding a two flute End Mill or Slot Drill with` inclined faces.

Howard
26 April 2021 at 19:22 #541739
alan ord 2
Participant
@alanord2
Thanks MichaelG but I was somewhat fortuitous. I took a punt and started searching ME first from the last issue. Checking each vol index until I got to the 2015 article. I wasn't going to go much further before abandoning ME and going onto MEW and EIM indexes. So think I was lucky.

Regards,

Alan.
26 April 2021 at 20:45 #541753
Robert Dodds
Participant
@robertdodds43397
Is the reprint article of Giles Parkes of any interest

From the Archives: Twist drill Sharpening by the Four Facet Method

Model Engineers' Workshop|May 2020 No293

The original article was published in 2000 MEW 64.

Bob D
26 April 2021 at 21:10 #541759
Martin Kyte
Participant
@martinkyte99762
Posted by Howard Lewis on 26/04/2021 18:58:59:

D A G is very expert at four facet drill grinding on his Quorn.

Four facet ground drills cut extremely well and a centre drill for starting is not obligatory.

Keeping the lip lengths equal is the secret to having accurately sized holes.

You are effectively grinding a two flute End Mill or Slot Drill with` inclined faces.

Howard

He claims, and there is no reason to doubt him, that his drills do not snatch in brass either.

regards Martin
26 April 2021 at 22:42 #541779
Emgee
Participant
@emgee
The method is detailed in the Quorn construction book.

Well worth the effort but I tend only to use the method on 1/4" up sizes.

Emgee
26 April 2021 at 22:59 #541782
Vic
Participant
@vic
Posted by Journeyman on 26/04/2021 17:18:45:

There is an article by Gadget Builder in HSM (Home Shop Machinist) try this link to his pages there is a whole load of info on drill grinding , jigs and some of the theory. Also a powered 4-facet grinder/jig ** Drill Sharpening **

John

Thanks for that John. I came across this quite some ago but is one of several good links I’ve “lost” over the years. It remains a very comprehensive article on drill sharpening.
27 April 2021 at 15:22 #541879
Howard Lewis
Participant
@howardlewis46836
Not sure who started four facet grinding of drills, but the late Giles Parkes advocated, and used it, on his Worden Cutter grinder. Relative easy to do, and well worth the effort..

Howard
27 April 2021 at 16:06 #541892
Douglas Johnston
Participant
@douglasjohnston98463
Posted by Journeyman on 26/04/2021 17:18:45:

There is an article by Gadget Builder in HSM (Home Shop Machinist) try this link to his pages there is a whole load of info on drill grinding , jigs and some of the theory. Also a powered 4-facet grinder/jig ** Drill Sharpening **

John

That is an interesting 4 facet grinder. Does anybody happen to have a copy of the article from HSM as I would love to have a look at it.

Doug
27 April 2021 at 16:38 #541897
Journeyman
Participant
@journeyman
Posted by Douglas Johnston on 27/04/2021 16:06:24:

That is an interesting 4 facet grinder. Does anybody happen to have a copy of the article from HSM as I would love to have a look at it.

Doug

I got a copy from John Moran (AKA Gadget Builder) try his Email: John at GadgetBuilder.com if you get no joy PM me and I will rummage in the archive and see if I can find it. He sent it to me as a web page.

John

P.S. Don't forget to change the ' at ' for a @

Edited By Journeyman on 27/04/2021 16:39:10
27 April 2021 at 16:45 #541898
Brian Baker 2
Participant
@brianbaker2
I have made Bernard Towers modified 4 facet drill grinding jig, from a pre published set of drawings and it works well. It is designed to fit onto the Stent, and makes the job straight forward and quick.

I think it should be published Bernard, and it is a useful addition to the Stent.

However, I have purchased a Quorn, which I like, and the Stent, including Bernard's jigs have been sold.

Publish it Bernard!

Regards

Brian B
27 April 2021 at 20:05 #541937
alan ord 2
Participant
@alanord2
Bob D thanks for the info. I will dig out the articles.

Alan
27 April 2021 at 22:46 #541966
Douglas Johnston
Participant
@douglasjohnston98463
Posted by Journeyman on 27/04/2021 16:38:08:

Posted by Douglas Johnston on 27/04/2021 16:06:24:

That is an interesting 4 facet grinder. Does anybody happen to have a copy of the article from HSM as I would love to have a look at it.

Doug

I got a copy from John Moran (AKA Gadget Builder) try his Email: John at GadgetBuilder.com if you get no joy PM me and I will rummage in the archive and see if I can find it. He sent it to me as a web page.

John

P.S. Don't forget to change the ' at ' for a @

Edited By Journeyman on 27/04/2021 16:39:10

Thanks for providing that email address John. I contacted John Moran and he has sent me the relevant files. This will keep me in reading matter for a while, then I will decide whether to make one.

Doug
28 April 2021 at 00:00 #541974
bernard towers
Participant
@bernardtowers37738
Thanks Brian, Article has been half written fo ages perhaps I should finish it!
28 April 2021 at 10:40 #542017
Howard Lewis
Participant
@howardlewis46836
The advice with an old kit for the Worden advised making a collet for each size of drill.

I followed, without realising, Giles Parke's method, of making an ER20 collet holder in a piece of 1" square steel, (The size used in the fixtures for the Worden. )

his allows drills of up to 13 mm to be held.

The drill is clamped in the ER20 collet, so that one cutting edge is vertical.

My holder is marked to identify the faces, so that rotating the holder through 180 degrees is obvious, if a an already ground face has to be revisited.

The Table is set square to the grinding wheel.

Fitted into one of the "standard" drill grinding fixtures (Inclining the drill at 31 degrees ) the complete assembly is swung through 30 degrees to produce the secondary clearance.

Once this is done, the fixture is reset to 10 degrees to produce the primary clearance.

The end result should be the primary reliefs being of equal width where they meet at the chisel edge in the centre.

Howard
8 September 2022 at 16:17 #612809
Alan Wood 4
Participant
@alanwood4
I've just completed a joint cooperation with John Moran to produce a hybrid 3D print / metal version of his four facet sharpener. The hybrid construction concept works very well making the whole thing much easier to produce.

You can download a ZIP file with Fusion files, STEP files and PDF drawings from my blog.
8 September 2022 at 16:50 #612814
Neil Wyatt
Moderator
@neilwyatt
Posted by Howard Lewis on 28/04/2021 10:40:09:

The advice with an old kit for the Worden advised making a collet for each size of drill.

I followed, without realising, Giles Parke's method, of making an ER20 collet holder in a piece of 1" square steel, (The size used in the fixtures for the Worden. )

his allows drills of up to 13 mm to be held.

The drill is clamped in the ER20 collet, so that one cutting edge is vertical.

My holder is marked to identify the faces, so that rotating the holder through 180 degrees is obvious, if a an already ground face has to be revisited.

The Table is set square to the grinding wheel.

Fitted into one of the "standard" drill grinding fixtures (Inclining the drill at 31 degrees ) the complete assembly is swung through 30 degrees to produce the secondary clearance.

Once this is done, the fixture is reset to 10 degrees to produce the primary clearance.

The end result should be the primary reliefs being of equal width where they meet at the chisel edge in the centre.

Howard

Coincidentally, Howard's detailed article on this subject will be in MEW 320!

I passed the proof half an hour ago!

Neil
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