Perfectly ground Twist Drills every time.

[John Stevenson 1Participant @johnstevenson1]

Posted by Neil Wyatt on 05/05/2014 20:31:12:

Sir J.That video is worth a thousand words!

Neil

.

Showed a profit for once then, – it was only 900 frames long…………

[VersabossParticipant @versaboss]

Many thanks Graham, now all is clear!

Well, maybe not – could it be that different species of these jigs exist? As I have other (better) means for drill grinding up to 13 mm, I don't use it often. Also the positioning lip was ground away long time ago, so setting up is more or less a matter of luck.

However, I tried it again today with a 15 mm drill. Without a wedge under the foot, and with the jig on the 59 deg. mark, I measured a tip angle of 120 deg, +/- 2 deg maybe. Due to the eyeball setup the drill cut about 0.2 mm oversize (directly into Alu and steel, without using a center drill…)

It seems what I really need is Mr. Hall's 180 deg. switchover gadget. Also a longer guide rod and something which prevents the different nuts from moving due to the vibrations.

Now I think I have stressed your patience enough,

Greetings, HansR.

[Clive FosterParticipant @clivefoster55965]

Nice one Micheal.

Looks to be the original of the Picador version with vertical pivot post and 5 to 5 drill lip alignment.

Clive

[“Bill Hancox”Participant @billhancox]

I have a similar model jig made in the US by General Tools. It must be forty years old and still in the wrapper. I was told years ago by various metalworkers that they were an abomination to use, so I never did unpack it. Now I will definitely give it a go with Graham's mod. Mod! That word of brings back memories …. of paisley shirts, mini skirts and Meccano erections.

[John Stevenson 1Participant @johnstevenson1]

If you look back far enough there were a load in 1908 and 1903 all based on the swing post method of operation.

Like many thing mechanical, nothing is new. it's only materials and electronics that are enhancing some of the old Victorian designs.

There is a thread going at the moment on the Eureka relieving tool. The basis of that was an advert from a magazine also from the 1900 era that Prof Chaddock and Ivan Law tried, and succeeded to reverse engineer from the sketch.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 05/05/2014 20:31:12:

Sir J.That video is worth a thousand words!

Neil

.

Neil and/or John,

Am I right in thinking that this comment belongs in the Eureka thread ?

… I searched here last night, but couldn't find any video posted by John.

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

I thing Neil was trying to save electrons by replying to two posts in the same reply.

Typical model engineer, tight arsed, moleskin trousers with deep pockets and drives a Reliant

[Michael GilliganParticipant @michaelgilligan61133]

Cheers, John

MichaelG.

[WALLACEParticipant @wallace]

Could not a similar variable offset be achieved with a set of spacers in a similar fashon to the one modified by Rik Shaw a few weeks ago ?

Definitely worth replacing the awful flat steel ‘bearing’ with something better but spacers might be easier to turn up than the eccentric.

Not sure I’ve thought through the geometry thoroughly so I could be wrong !!

W.

!

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 06/05/2014 10:34:00:

Typical model engineer, tight arsed, moleskin trousers with deep pockets and drives a Reliant

.

… forgot to mention; mine was a Scimitar Coupé with a nice "blueprinted" V6 and decent wheels & tyres.

MichaelG.

[NJHParticipant @njh]

Michael

Well I don't think a Scimitar  is too useful a vehicle for everyday use. On the other hand I suppose it might be useful to subdue JS comments! ( sorry John )

Norman

 

Edited By NJH on 06/05/2014 12:48:24

[Neil WyattModerator @neilwyatt]

I'll have you know I would never wear moleskin. I'm very fond of moles.

Neil

[John Stevenson 1Participant @johnstevenson1]

Moles – Bloody scourge those things are.

We used to catch them as kids and bury them alive.

[Gordon WParticipant @gordonw]

Well at long last I am a fully authenticated Model Engineer . Moleskin trousers, hairy jumper, very deep pockets ( yorkshire man in Aberdeenshire) Drive a 2CV .

[Michael GilliganParticipant @michaelgilligan61133]

On the subject of van Royen …

I was somewhat amused/bemused by this on "myhobbystore"

MichaelG.

[WALLACEParticipant @wallace]

Hi Gray.

Yep, I can see the detents would be lost – after I posted the suggestion, I dug out my unloved grinding jig to have a look….

Is there anyone out there who doesn’t have one stuck unused on a shelf somewhere ?? !

But it is shocking quality -and has prompted me to have a look at a Reliance jig to see how that works with maybe possble improvements…(although my long term plan is to go down the 4 facet route using a jig that takes er32 collets on my Union t&c grinder – eventually ! )

W.

W.

[LynneParticipant @lynne]

Hi, MEW 176 & 177, Drill Sharpening Jig, by John Shepherd, well worth a read.

2nd attempt. 1st showsin 'My posts', but not in thread .

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Lynne on 07/05/2014 04:54:00:

2nd attempt. 1st showsin 'My posts', but not in thread .

.

Lynne,

Your 1st is there, at the bottom of page 3

MichaelG.

[John HaineParticipant @johnhaine32865]

MichaelG, myhobbystore have clearly run out of bits, so we'll have to wait until they are re-stocked!

(But how come we can still see this web site?)

[Michael GilliganParticipant @michaelgilligan61133]

John,

Nice

MichaelG.

[BazyleParticipant @bazyle]

Posted by Graham Meek on 06/05/2014 15:08:18:

Finally I am convinced that the excessive off-set built into the jig originally is to cater for drills with a different included angle, i.e. the other settings on the jig, (one size fits all). I have not bothered to look into this as my requirements for different included angles is zero, in my 40 so years of Toolmaking I cannot remember one instance where I have needed such a drill.

Gray,

Thanks for that. I was gong to ask what the other settings were used for. When I find mine I can just pin the wobbly joint permanently.

[Thor 🇳🇴Participant @thor]

Hi Gray,

thanks for the additional photos and explanations, much apprerciated.

Thor

[Neil WyattModerator @neilwyatt]

Graham,

I had a 'play' with my plasplugs multi grinder yesterday. The drill holder is clever but imperfectly realised, although it's simple design does make a decent job of holding the bit at the same height for each flute.

Drills are ground at the top of the wheel, and the grinding is more or less normal to the cutting edge.

The setting jig has a triangular steel 'ramp' that sets the bit protrusion. A moveable 'V' at right angles to this sets the drill orientation by a four-point contact. You can use this as a check for symetrical grinding.

Drills are presented to the wheel with the bit turned slightly to the right, which more or less puts the cutting edge along a radius near the top of the wheel. An invisible, but presumably off-centre, pivot creates the backed-off edge as you turn the holder.

The weaknesses of the design are two fold – the tiny 70W motor struggles to keep the grinding wheel going at speed under any sort of pressure – so it's best for worn, not damaged, cutters. Secondly the plastic construction and some spindle end play mean you need to develop a consistent 'touch'. regularly turning the drill 9rather than doing one side at a time helps. The Tip angle seems to be accurate.

I suspect it would be worth duplicating the jig in metal.

Does anyone know how the sharpeners that have a drum with various holes for the drills to be poked into work?

Finally, anyone seeking the digital article (or other digital content) on MHS will be delighted to know that the effect of a system reset that rendered all digital editions 'out of stock' has now been rectified.

Neil

[Neil WyattModerator @neilwyatt]

Hi Gray,

My jig appears to grind more or less accurate at 59 degrees, using an engineers protractor on the drill tip, a few days ago.

Neil

[Neil WyattModerator @neilwyatt]

About 6 degrees, as best as I can tell by sighting across, but only a short portion of the pin is visible .

I deleted a duplicate post – the system seems to be throwing a few today.

Neil

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