Harold Hall's book "Tool and Cutter Sharpening" has a good description of how these jigs work and a simple mod.

Russell

If its a genuine Picador grinding jig it needs no modification. Just follow the instructions and it will work just fine. The major weakness of the Picador jig lies in setting both drill projection and tip rotation angle accurately and repeatably. Picador jigs have the pivot pin vertical and the drill cutting edges set at 25 past 11 orientation for sharpening.

Takes a certain knack but once you have got the idea your drills will be sharp. I do mine more by eye than by reference to the gauge. I also remove and replace the drill after setting up so that cutting conditions are the same for doing the first edge as they are for the second one after flipping the drill 180°.

Drill holding and location is where "build down to an affordable price" rough edges show. Nothing that a bit of skill and care can't overcome but it does mean things aren't quite as easy as the instructions suggest.

If I wanted to seriously improve a Picador I'd take a close look at the flip over drill holder and integral Vee gauge setter used on the original Plasplugs multi sharp system which uses the same drill cutting edges at 25 past 11 angle setting. A really clever set up that takes all the guess work out. Would have doubled the price of Picador jig tho' and they weren't objectively that cheap back in the days when I got mine, £5 ish around 1973-4 in a closing down sale I think.

The modifications referred to apply to the cheap copies of the American "General" brand device having the pivot pin angled back away from the grinding wheel with the drill cutting edges set vertical. Good quality brand name ones e.g. Spiralux in the UK will work as per instructions. Cheap imports that don't work will have unquantified and unknown errors of construction leading to poor results. Most of the internet and, regrettably, far too many published witterings are "how I fixed" mine stuff. Fine if yours has the same constructional infelicities as that of the writer. Odds of that are …. If you want to sort one of those copy Graham Meek. As ever Graham takes no prisoners and gets it right. Do what he says and it will work properly. Probably better than the original designers ever envisaged.

Clive.

Edited By Clive Foster on 07/05/2018 11:06:33

Edited By Clive Foster on 07/05/2018 11:07:27

Robert,

If your jig is not made from light alloy, could it possibly be a Reliance?

**LINK**

HTH,

Rod

Neil [Nimble]

A couple of typos seem to have crept into that URL, but this seems to be the thread you were aiming for: **LINK**

http://www.model-engineer.co.uk/forums/postings.asp?th=95436&p=1

Regrettably, the thread now contains everything [?] except Graham Meek's input … so it makes rather disjointed reading.

MichaelG.

I have the Spiralux version where the tool is angled towards the grinding wheel. I don't use it much because I don't do that much drilling! I have found that it is of little, ie no, use for drills below 1/8 in, which in any case are cheap enough to replace. For larger drills, it does seem to work quite well.

Probably the biggest problem I have had is that the two screws holding the adjustable lip guide (correct term??) on to the alloy body have eventually worn away the thread necessitating a retap in a larger thread, 2BA being what I used.

The comment re hollowing of the grinding wheel side is a valid one, whether or not a cup wheel would be satisfactory I suggest may be debateable as the device requires a relatively large area for the drill bit to swing against. Presumably a cup wheel with a large, ie wide, grinding area would be ok.

Regards,

Peter G. Shaw

First, I have a set of original Picador instructions, if anyone needs those. I have the original device, which I bought some 40+ years ago, and it works very well indeed. The instructions are peculiar to the Picador, and the projection of the drill bit beyond the front of the Picador is very different from other makes.That's because the geometry underpinning the jig is different from the Reliance-type jigs. So if you slavishly follow the Picador instructions with a Reliance-type jig, you will not get the intended result.

Secondly, my own opinion is that one should not grind on the side of the normal type 1 wheel which is found on most basic grinders, because the working face of a type 1 wheel is the front, curved, face. Yes; I know most people use the side, and that's what's shown in most drill jig manufacturers' instructions. I don't wish to start the usual argument, so I will leave it at that. My point is that the drill bit moves very little during its swing. If the drill jig was swung through 90 degrees, so that the drill lip sat horizontal, the drill could be sharpened against the curved face of a wheel. Some jigs are designed to do just that. I have a flat-faced type 6 'cup' wheel with a narrow face (8mm or so), on my grinder, so I use that, with the jig orientated in the 'normal' way, with its foot on the bench. I have a grinder and Picador set up permanently for sharpening drills. Each to his own.

Picador is Picador, and there is no real Picador-type, as the geometry of other makes varies either slightly or a lot, despite what are, at first glance, similar looking styles.

Picador made, I think, 3 sizes of jig. I have never seen the large one, which sharpens drills larger than 1/2 inch, if I remember correctly.

There are lots of other good drill sharpeners out there, of entirely different design, and I have a substantial collection of them. The geometry of the sharpened drill bit is similar, in the good ones, but the means of arriving at that geometry sometimes looks radically different. I understand the more recent Far Eastern pattern copies are not of the Picador, but are more like the Reliance, and they contain a built-in incorrect angle in the base unit. Graham Meek's article sorts that quite elegantly.

Marcus

Hello Marcus could I also have a copy via a PM. John

.

Robert,

If you a referring to the images in the link posted by Vic … it should be a simple matter of opening them 'full size' and then saving the jpg image, to do with what you will.

MichaelG.

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[detailed user-input will vary according to what operating system you use]

Glad to hear that the printing problem is solved.

Thor