And Ps: I was taught "Never grind on the side of a grinding wheel" Where did that go out of the window ??

Language is used in a context. The truth of a statement has to be assessed within the context in which it is made.

If we want to modify what you have been taught, we could say 'never FREEHAND grind on the side of a grinding wheel'.

There is a huge difference between you pressing a rusty bit of iron into the side of a wheel and the delicate, controlled movement and depth of cut the jig produces. One is freehand grinding where the advice is good and correct. The other is tool/cutter grinding where it has less validity.

If I mention cup and saucer wheels, can we have a discussion of what constitutes the side or face of these?

My understanding for this, is that it's difficult to dress the side of the wheel.

David

Removing and replacing the drill after setting the point projection before grinding the first edge gave me more consistent results.

Presumably the actual position taken up by the drill point when adjusting the projection can be slightly different from that resulting from simply putting the drill into a preset jig. Most likely due to the difference between sliding against the little rotation setting gauge on the end as you set projection and simply placing against it when merely inserting the drill. Any such effects mean the point grind will differ between the two edges.

Using identical insertion technique on both edges avoids this, very inconsistent, effect.

I also made a U section guide mount for my base. Needed to make it higher to reach the right part of my grinder so it seemed sensible to make sure it always stayed perpendicular to the wheel when setting the base. Plans to add a screw adjuster to reliably set the position and add the requisite tiny cuts between swings never reached fruition.

I did try making a tighter, more controlled swing pivot than the simple, rather flexible, plate across the cast Vee in the base. Which significantly dis-improved performance! On reflection many years later after getting my Clarkson attachment I reckon the flexible plate acts as a crude spring limiting the force on the drill point when grinding. The Clarkson has a proper spring for this. Presumably too solid a mount gives too much force on the wheel and poorly controlled grinding.

The grinding a hollow in the wheel objection is valid but probably moot given that this is a consumer grade product and that most won't get enough use to seriously consume the wheel. I put a cup wheel on my grinder. Not only a complete solution to any such worries but also letting me fit a large grinding rest perpendicular to the spindle. Simplified Hemingway Worden style. The Picador base lived underneath. Two studs and wing nuts held the table down so it could esily be removed for drill grinding.

John is a bit unfair in in his comments about cheap screw threads. Its fair to say that, as an unfortunate necessity to meet a price / performance ratio acceptable to its target market, the constructional and engineering standards of the Picador are lower than one would ideally like. As is the case with all such devices.

I got mine around 1972-74 on a special offer price, reduced from £7-50 to £5 as I recall things, when I was earning maybe £650 a year. In those days cheap crap wasn't cheap! You could buy a half decent 1/64" to 1/4" drill set for similar money.

Significantly better engineering would have been unaffordable.

If you were going to make a better device you'd use a different design.

feel its a great pity that an updated version of the concept using the ingenious flip over Vee drill carrier and drill point projection gauge used on the original PlasPlugs drill sharpening system has never been produced. This would effectively mechanically resolve pretty much all the set-up related issues.

I imagine that given the will a really nicely engineered set-up to use with your grinder could be made for less than the rather cheaply made "£40 (ish)" PlasPlugs grinder system knock offs with integral grinder from the usual suspects.

Clive

Edited By Clive Foster on 01/06/2022 09:39:29

Might I suggest a search of the forum as there have been a number of threads concerning this topic. In particular, try a search for "Spiralux" and also a search for "Graham Meek – Mods to (copies of ) Picador drill grinding jigs."

I own one of the Spiralux jigs which incorporates a slight angle on the spindle around which the actual jig rotates. My reading is that this "lean" is beneficial. Sorry, I can't tell you what the angle is, or which way, although I think it's toward the grinding wheel. Obviously mine works which means that I haven't paid any real attention to these threads.

I have found that for drills below 3.0mm, well, forget it! For drills between 3.0 & 4.0mm, it is possible but requires a lot of care. Drills between 4.0mm and, oh, dunno, 10mm say, the jig is satisfactory – as long as you can get the drill into the jig. The end result is that for drills below 4.0mm, I buy in packs of 5, others I sharpen.

Grinding on the side of the wheel. Well, enough has been said already. It is acceptable as long as the loads are kept light.

Cheers,

Peter G. Shaw

p.s Incidently, my biggest problem is that my grinder, bought some 30+ years ago, gets hot, very hot, sometimes too much to touch, if used continuously, hence I limit my grinding until the grinder becomes noticeably warm.

Personally I do use a Picador jig, along with a Reliance, and a Potts, but since I have a Clarkson grinder, I use that for the actual grinding, rather and a double ended off-hand grinder.
I use one of these recessed wheels from Axminster, which does the job nicely and has a bit more thickness, so I'm able to dress the side of the wheel.
https://www.axminstertools.com/axminster-wide-wheel-for-awbgdl-bench-grinder-400074

Bill

This was my final set-up using my much modified Non-Picador grinding jig. A White recessed wheel from Axminster and a diamond, set-up so as to sweep the entire face. There is a micrometer adjustment on the diamond. This method also produces the grinding marks on the drill lip for maximum cutting edge longevity. (Grinding marks should be at 90 degrees to the cutting edge for maximum cutting edge life).

Regards

Gray