The Correct Way To Sharpen Drill Bits Using A Picador Drill Sharpening Jig With Custom Base

Peter G. Shaw - You raised some good points.

Lots of opportunity to refine and modify once someone has the basic setup.

The purpose of the post was to keep it simple initially so that the user can gain confidence and experience.

I found it no problem grinding drills from 3mm to 3/4" as specified by the Picador instructions.

Once you have the cutting edges in the five-to-five position is is really very simple.

Once you have done a few drill bits you gain some experience.

R

Edited By Richard Kent 1 on 01/06/2022 11:41:48

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

peak4 - Bill, your setup sounds good.

The Picador jig works well an as described especially for what is cost and is especially good if someone is on a budget.

I have not found the need yet to purchase a more 'upmarket' grinder as the Picador restores my drill bits to "as new" condition.

R

Edited By Richard Kent 1 on 01/06/2022 12:51:19

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

Something worth looking at about sharpening using this type of jig.

Unfortunatley you may need to sign in It links to a PDF which I have but can't insert here

Edited By Derek Lane on 01/06/2022 13:20:42

Graham Meek - Looks great Graham.

If someone has the time and inclination for modifications etc then they should go for it.

I tried to keep the original post as simple as possible for those people who want to use the original Picador jig which I found works as described if set up properly.

R

Derek Lane - Thanks for the info Derek

is it just my eyes or do the sharpened drills have rather long central chisel edges?

JasonB - Thanks for the info.

Some clever comments here today - Not your eyes- it's photographic distortion - 2D representation of a 3D object.

The bits were ground according to the instructions.

They drill and work perfectly fine.

Just like new drill bits.

P.S just double checked them by eye against the photos and it is indeed photographic distortion.

The best way to evidence this is for someone else to grind some bits on their Picador jig and compare the results.

Or perhaps send me a drill bit and I will sharpen it and send it back to you for testing?

Edited By Richard Kent 1 on 01/06/2022 13:46:07

There's a few comparative photos in this thread, the first post of which has a link to a different thread again.
https://www.model-engineer.co.uk/forums/postings.asp?th=139828

Bill

peak4 - Thanks for the link Bill

If anyone is interested in talking about comparative results then they are welcome to do so.

I say "fill your boots"

As for my setup works perfectly well for me.

I am getting consistently good results.

As mentioned earlier, if someone wants to send me some drill bits for interest sake I can sharpen them and send them back.

Just came across this thread and am a little confused as you say that you use silicon carbide wheels. I have been under the impression for the last 40 plus years that that material is for soft materials and carbides but am ready to be told otherwise. and as for grinding on the side of the wheel is NO NO NO the reason being is that when using the front face the wheel is in compression but on the side you are trying to separate the bond. Ask Norton abrasives what they think.

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The trouble is … they put out stuff like this:

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MichaelG.

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Edit: __ You may [or may not] be interested to read the current H.S.E. Guidance, which I linked in this recent thread:

https://www.model-engineer.co.uk/forums/postings.asp?th=177532

My post timestamped : 20/03/2022 08:27:45

Edited By Michael Gilligan on 01/06/2022 23:19:32

Michael Gilligan - Mike, thanks for your post. Please see my reply to bernard towers above....

Edited By Richard Kent 1 on 02/06/2022 09:50:33

I will admit that when I'm using my Picador jig, It's on the surface grinder rather than on the side of the pedestal grinder. This it actually far superior to the pedestal grinder setup. One can advance the feed with the cross feed of the grinder instead of the nasty nut on the jig, this gives a repeatability of a tenth of a thou, which is better than the rest of the jig can achieve.

One can then grind one side of the drill, wind the feed back, rotate the drill, then grind the other side to the same amount all without having to keep flipping the drill over multiple times.

Picador did make a larger jig, for drills over 3/4". Those are as common as rocking horde leavings.

I have one of those Picador type jigs brand new in the box that has sat unused under my grinder bench for at least 7 years since I rescued it from an old guy's shed where it sat for I don't know how long. Still not sure after reading all this if it's worth setting up. It is on my Round Tuit list though. I have spare 6" grinder and piece of board to set it up on. Might look at making some better fine adjustment screws etc for it after reading above comments. Something in 40TPI with a micrometer collar to really dial it in could be a nice little project.

Meanwhile, an extra seven years of practice at freehand sharpening and I get by ok. Anything under 1/8" is a challenge due to eyesight these days though.

Edited By Hopper on 02/06/2022 10:25:04

Mark Rand - Mark, appreciate your comments.

I was showing how it can be done with a 'minimal' setup

If you have a surface grinder then that is great.

Regarding the Picador mounding bracket. As you can see from my photos, I fabricated a new one.

The bracket is only used to offer up the drill to the grinder for the first 'cut' and beyond that you use the screw on the Jig for successive 'cuts' which ensures you keep the drill profile correct as you take more material off the drill bit.

R

Edited By Richard Kent 1 on 02/06/2022 10:31:16

Hopper - A picture of my mounting board below...............

Hi, there seems to be many opinions of how to use these attachments and here are three that say you should use the face of the wheel, Draper images- amazon.com Iinstructables.com. If you must use the side of the wheel, in my opinion and the way I was told in my Abrasive Wheels Course, is it should only be very light and should be as close the face as possible, where any wear will be dressed out during normal maintenance of your wheels and you should avoid dressing the sides of the wheels and certainly not using a star wheel dresser. one of the worse illustrations I've seen, is this one where it is shown near the centre of the side of the wheel, where you really don't want to weaken your wheel Sealey,

Regards Nick.

Nicholas Farr - Hi Nick - Thanks for your comments. The way you have suggested do this is the same way as the Picador instructions - taking small cuts. It is interesting to hear other people's point of view.

Edited By Richard Kent 1 on 02/06/2022 11:34:38

Edited By Richard Kent 1 on 02/06/2022 11:34:52