|Stephen Osborne||01/09/2018 10:03:39|
|14 forum posts|
Graham Meek's excellent article re his modifications to the Picador drill grinding jig, contains many photographs, but no drawings. Does anyone know if such drawings exist and if so, where can I find them?
|Mike Poole||01/09/2018 11:26:01|
1805 forum posts
Have a look here Graham explains what he did to get a picador type jig to give better results.
Edited By Mike Poole on 01/09/2018 11:26:23
I think you have probably read the article, must read the question properly!
Edited By Mike Poole on 01/09/2018 12:04:41
|Clive Foster||01/09/2018 12:46:37|
|1635 forum posts|
Nice link Mike.
Two weaknesses in Grahams treatment tho'.
1) Not really made sufficiently clear that these modifications don't apply to the true Picador drill jig with vertical pivot. The Picador jig with its vertical pivot and 5 to 5 cutting edge orientation uses a different movement geometry to generate the conical point. The tilted pivot variety use a crude approximation to the Van Rouen (spelling?) geometry as used on the Reliance, Potts and other more sophisticated grinders. Biggest issue with the usual die cast suspects is that they have to be made cheaply enough for ordinary folk to afford for occasional use. Graham has very effectively shown how to re-work the them into something approaching the performance of a more highly engineered, sophisticated (and expensive) version.
That said the true Picador could use a seriously better method of setting drill point projection, especially for small drills. Not sure that anything greatly better is possible with the Vee trough holder. The flip over holder and separate setting gauge concept as used in the original PlasPlugs drill sharpening system looks much better bet. But if you are going to do that might as well start over with an improved PlasPlugs device and be done with it. Not as hard as it might seem once you have the geometry figured. I sketched one out then a drill sharpening jig for my Clarkson appeared at "wallet came out smoking" price and the whole thing became moot.
2) The relationships between drill centre line offset relative to the pivot axis, pivot angle off vertical and drill point projection are both complex and inter-related. Several ways of getting to the same place for any specific size of drill. In practice the objective is to choose a set of dimensions that works adequately well for reasonable range of sizes. Not really something you want to try figuring out for yourself unless good at 3D geometry maths and like headaches. As Graham has shown a skilled worker can get a pretty decent solution empirically. A bit more guidance for Mr Ordinary Guy or Ms Ordinary Girl wouldn't have come amiss.
I seriously admire Grahams work. Always thought that attempting to do anything with these devices would be rather futile lily guilding and silk purse from pigs ear efforts with any gain not worth the work. Graham came to a different conclusion and has handsomely proved himself right. Well done.
|Stephen Osborne||02/09/2018 13:04:54|
|14 forum posts|
Thank you Mike & Clive for taking the time to reply.
Mike - the link you provide takes me to the exact article I referred to. Nice photos but no drawings.
Clive - I am confused with the various jigs around. Mine is a Picador with a vertical pivot pin. As it is in a very original looking Picador box, I assume it is not a clone. Would this model be improved by Graham's mods?
If so, my original question remains - are is there a set of drawings of the mods in existence?
|Rod Ashton||02/09/2018 13:13:47|
|280 forum posts|
+1 for drawings if anyone has them please.
|Graham Meek||02/09/2018 13:48:03|
|70 forum posts|
I had asked Neil to supply a short note to confirm that the Picador unit does not need to be modified. It works on a completely different principle to the "Clones". A friend has recently purchased a Picador complete with box and instructions. It worked flawlessly straight out of the box.
The original "Spiralux" unit introduced the leaning pivot pin. It also featured a different base which did not need the wedge shaped piece that I added. I think it would however benefit from the revised pivot pin arrangement. A picture of this design can bee seen on the following link, but you will have to "log-in"
The previous link on the second post was an article which was a precursor to a more detailed follow-up article. This appeared in EiM not long after my original post on this Forum, "Perfectly Ground Twist Drills every time". This article contained all the necessary drawings. As regards which issue/month that was I cannot say without wading through my back numbers. I am sure the more meticulous on this Forum have the answer to that.
I hope this clarifies things.
|Michael Gilligan||02/09/2018 14:02:59|
12766 forum posts
It doesn't answer your specific question, I'm afraid ... but it may be useful for you to read through this previous thread: **LINK**
... It's all rather disjointed now that Graham Meek's contributions have gone.
|Phil P||02/09/2018 14:55:17|
|446 forum posts|
Some info here as well.
|Neil Wyatt||02/09/2018 16:49:49|
15697 forum posts
As I said in my email, I feel Clive Foster's post made the points you asked me to highlight.
|Stephen Osborne||02/09/2018 17:28:49|
|14 forum posts|
Many thanks for all your comments, most helpful.
Nice to know that no modifications are needed to my Picador jig.
|Clive Foster||02/09/2018 18:34:53|
|1635 forum posts|
I've had my Picador for 45 years or so and its always produced nice sharp drills once I've got my eye in. That said I'd never guarantee to get one drill right first time so tended to stock up and do biggest one first as its easier to see any errors. My standard error is to set the drill with too much projection so the swing radius of the drill end is too large leaving insufficient or even negative clearance at the heel. Hafta say I've never really mastered the setting finger thingy.
I made a U shaped guide permanently bolted to the bench to ensure that the base always moved perpendicular to the wheel when adjusting. The plan was to fit a fine thread adjusting screw so that grind depth could be accurately and repeatably controlled but there always seemed more urgent things to do. Pretty sure it would have been worth the effort though because using the standard system generally involves setting to grind a bit too deep then keep swinging until no further grinding occurs. Flip drill and repeat.
I always found it imperative to remove the drill and re-fit it after the basic setting had been made before grinding the first cutting edge. Drill position achieved during adjusting never seems to be quite the same as when inserting a drill into the adjusted jig. Another trap is over tightening the holding device as it can tilt the drill slightly in the trough. Just enough to make a right mess but not enough to be obvious. Look down both sides of the Vee to ensure proper contact all along the drill.
After maybe 15 - 20 years I switched to a narrow cup wheel for tool sharpening. This seemed to give more consistent results with the Picador. Possibly because I regularly dressed the cutting face (1/4" or 3/8" can't recall which) with a diamond. Being a proper brand name white wheel the cup wheel was probably rather better than the Taiwan standard ones that came with the Whitcolt bench grinder bought 40 years ago when Mr Black & Mr Deckers bottom of the range one let its magic smoke out. Actually a more than decent machine, especially given the price, save for the inadequate tool-rest issue endemic to import machines.
It seems to me that an adequate projection gauge could be made if a vertical plate were set up alongside the jig so that turning the jig through 90° would permit the drill point to be set so as to just touch the plate. Main issue would be making arrangements to set the plate position so as to correctly register the drill point projection for any given drill size. The ideal would be to use the drill shank as a positive gauge. Scales are easily misread and turns of adjuster screw miscounted. For me (yet) another of those "life is to short to sort it our properly" things.
|Stephen Osborne||03/09/2018 09:50:47|
|14 forum posts|
Thank you Clive, it seems I have a lot to learn.
I am new to the Picador and am using it with an old MES Tool & Cutter Grinder that I made with a set of castings about 30 years ago. With the tilting table removed, the Picador bolts to the bed nicely and offers up to the cup wheel perfectly. My first attempts have been encouraging.
|124 forum posts|
Hi all. Did we ever get to answer the OP original question - where are the drawings to be found.? I would also like to modify my non picador jig and would like to access the drawings. I have looked through the eim index and my back copies of eim but cant find anything.
So if anyone does know or can post the info please share the location!
|larry phelan 1||08/09/2018 18:28:36|
|393 forum posts|
Seems to me like there is room out there for someone to come up with a simple reliable jig to sharpen drills,which does not cost an arm and a leg. My attempts at free hand sharpening leave a lot in the hands of the Gods,and we all know how fickle the Gods can be [most times,in my case ]
Many moons ago,I bought a sharpening device made by Markel,but could get no good of it at all,so it ended up on the shelf. Time came when I became the proud owner of a large collection of blunt drills [still have a few] so I dug out my drill "sharpener! to have another go,and to my surprise,this time around,I got fairly good results. [Well,at least they cut rather than rub] Not perfect by any means,but anything is better than the way it was. I grind as near as I can on the bench grinder,then finish off with the Markel jig.
When you are all finished laughing,remember this; Half a loaf is better than no bread !
This unit is easy to use and not too dear [if it,s still around ],so for those of you like me,a very small number,I suspect, it might be worth looking at. Just dont tell anyone you need to use something like this. I keep it hidden when "Experts! call around.
Those who can sharpen by hand are lucky,and few and far between.
Remarks,kind and otherwise on a postcard please ! All welcome.
|Graham Meek||08/09/2018 19:09:39|
|70 forum posts|
At post number 6 above I wrote,
"The previous link on the second post was an article which was a precursor to a more detailed follow-up article. This appeared in EiM not long after my original post on this Forum, "Perfectly Ground Twist Drills every time". This article contained all the necessary drawings. As regards which issue/month that was I cannot say without wading through my back numbers. I am sure the more meticulous on this Forum have the answer to that."
|thomas oliver 2||08/09/2018 20:01:45|
|102 forum posts|
Your drill sharpening troubles are now all over. I use drills every day and I have 5 sharpeners all of which suffer from the same problem, even my Picador which I used successfully for many years in my old shed - the need to reset the other edge every time I even have a hand sharpener made by Eclipse which is worked on a sheet of carborundum back and forth - the backing off attained by eccentricly mounted wheels Lidl stores sell a multi sharpener which includes chisels, planes, scissors, garden shears to name a few,, For drills, the bit is mounted in a separate holder and set for length in a v-jig then clamped. The edge is sharpened and then the holder is inverted and the other edge sharpened. This ensures that both edges are the same length and angle. The wheel is diamond and a spare included. I sharpened umpteen drills perfectly in no time, They cost only about £15.00 whereas on ebay the cheapest alternative clone is £42.00 ans one as much as £60.00 Incidentally, even if your local store does not stock them, they can be ordered quite easily on line.
|Frances IoM||08/09/2018 21:24:55|
|574 forum posts|
|The Meek articles are in EIM March 2016 pp318/9 + continued in following month (not for nothing do I joke that the title should be engineering in multiple instalments)|
|David Davies 8||08/09/2018 21:25:30|
|8 forum posts|
I have taken note of Graham's post of 2nd Sept and repeat above. After looking at the EIM index I believe that the details are in the May and June 2016 issues of that mag. My next job is to find copies.
One other thing, Graham, did you develop a design for your 'Hardinge' type screw cutting clutch system for the Boxford lathe? I'm sure there are many who would be interested.
|David Davies 8||08/09/2018 21:25:38|
|8 forum posts|
Delete duplicate post and note that Frances beat me to it!
Edited By David Davies 8 on 08/09/2018 21:27:43
|Rod Ashton||09/09/2018 10:49:12|
|280 forum posts|
Anyone use a Drill Doctor??
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