D.I.Y. Axe and cleaver sharpening jig

[aquataur]

This is a description of a jig I made for sharpening axes. Nothing speaks against using it for cleavers or other blunt instruments too, but I have not tried it. I hope you will.

If there were a subforum for axes, then I would put it there, but there is none.
Using it for cleavers however justifies its relationship to knives.

Tormek´s jigs for knives clamp the knives on the spine, hopefully symmetrical around the center to achieve symmetric bevels. Using the available knife jigs, a given knife in the jig gives a projection distance of some 10-15cm, and that´s what the whole system is set up for.

With a chosen grinding angle, this results in a certain T-USB value. All available calculators spit out the corresponding value. So far so good.

Unfortunately there is no jig commercially available that clamps an axe in a comparable way.
There are many ways an axe could look like on its butt, many shape it could take on, and there could be huge variations in thickness. A jig like the knife jig that grasps from the back would most certainly fail.

The projection would become enormous, and T-USB with it. The attempt to use their huge support bar is a palliative measure and does not necessarily touch the problem. The axe jig clamps, but does not help much otherwise.

So I thought, what clamp is adjustable? A screw clamp. It even has a pressure plate that can adapt its angle to the surface with its ball-bearing like holder and thus always stays put.

Unfortunately the other side of such a clamp is fixed. So I bought two of them, and out with the angle grinder, and I mounted the two adjustable halves facing each other with a common spine like shown in the picture below.

For the axe shown, I clamped the jig approximately at the center of the circle the cutting edge describes, or slightly behind that (see later). This lets you pivot around that point. I used the known techniques of lifting and pivoting.

If you take care, the axis of the two screws (resp. the rod) is perpendicular to the axe´s surface, which will guarantee symmetric grind. The two screws function as a pivot point, and the axe becomes the jig. The double clamp grips perfectly, particularly if you have the spine flush against the axe´s butt.

This contraption has several similarities to a knife clamped in a knife jig:

• short projection
• symmetric clamping
• all calculators work

I used the usual calculator, but with a slight change. The calculators work with the center of the jig plane, and they half a given diameter automatically. So haul out your calipers, measure the axe´s width at the clamping point (in other words: the distance of the pressure plates) and enter that value in the position where the "jig diameter" value goes.

When grinding the traditional way (with the stone rotating towards you), you have a certain downwards tilt, just as you would with a knife. Now with the c-clamp jig (I call it the Bessey jig) the USB´s horizontal rod rests against the clamp´s screw (see picture below). The USB bar may initially rest against the pressure plate, but soon before long it will slip over the pressure plate´s rounded edge and find its final destination at the screw. So take care that you always rest against the screw and not the pressure plate when you are changing sides.

Acute readers will notice that this changes the angle, but I found that the angles come out right (gauged with the notches on the angle master) when you measure the axe´s width inclusive the pressure plates at their top. Because that´s the surface the USB finally rests upon.

I made two axes so far. According to John Juranitch´s advise, I thinned down the region behind the cutting edge somewhat. I also polished this relief with a JIS1000 stone, which is more of a cosmetic thing probably. I did not polish the cutting edge. As you see, it holds up nicely after a fair rake of hardwood at a 40 deg inclusive angle.

This jig costs very little and does not require any additional expensive accessories or any contorted postures by eliminating large projection distances.

For the axe shown, the projection distance was 148 mm. At a 20 dps angle the resulting T-USB value was 96 mm. This is fairly at the limits of what the USB can be pulled out (I can only speak for a T‑3) but would come down if I had chosen clamps with a larger depth. The clamps´ depth is 50-60 mm. Next time I get a pair of larger ones. Note the axe it not rusty as it may appear, this is painted with linseed oil, as is good practise.

I can see that this works on cleavers too. The length it grips "forward" just depends on the depth of the clamp you choose. For a cleaver, the depth of the clamps used would probably be perfect.

And don´t forget to reset the jig diameter parameter after use.

(please excuse the less than stellar photographic skills. This is not an art contest.)

[Ringarn67]

That was very cle(a)ver 
Jokes aside, what a brilliant idea.

I have sharpen a bunch of axes and struggle to get nice and even bevels.
Mostly due to the axes have been used as a sledge, (with the backside, not the edgeside)
Will make one for sure.

*thumbs up*

[HaioPaio]

Thanks for showing your helpful solution.

[aquataur]

Great that you find that useful. That rewards my effort.

(...) axes have been used as a sledge, (with the backside, not the edgeside)

That is quite common, because it is intuitive. I have done it until I recently read (surely in one of the sharpening books) that the heavy butt end is solely there to balance the axe. It should never be used as a sledge hammer, although it looks like.

But who of us laymen seeks training for the feed and care of axes?

Logic dictates that you use clamps with sufficient depth so that you can grip ahead of the mutilated area.
On the other hand, don´t choose them too large; I think an integral part is the spine of the clamp (if that is the appropriate term for it...) resting firmly against the axe´s butt.

For the axe shown, the proposed radius´s center does not quite meet the mounting point. But like sharpening a knife, you control those things with lifting the handle and/or pivoting. So since the axe is a rather coarse instrument, unlike a delicate knife blade,  you have plenty of passes to see where you get.

And as some of the renowned sharpening masters said (about chisels): Don´t worry about razor sharp. The blade ist only razor sharp until the moment it meets wood...

[RickKrung]

I did something quite similar about five years ago.  Worked great.  The clamp I used was similar to the one used here, only one-sided.  Even so, I was able to use it for both sides without changing. Haven't had the need since, so it is great to be able to use something already on hand.

Rick

[aquataur]

Yes, there is actually nothing new under the sun 

As one might expect, there is very little new in electronics, at least in analog circuitry. (...) Sometimes the innovators try to make their transfer of known electronics methodology from one discipline to this one seem revolutionary. The revolution is not actually the technology, but rather its revelation to the rest of the world.

- Kevin O´Connor: The Ultimate Tone Vol 4, Power Press Publishing, Thunder Bay, CN, 2006, p. 4-15f 

[Drilon]

A super solution. Will try it the next days!

Drilon

[cbwx34]

This is a description of a jig I made for sharpening axes.
...

Nice job.  Others have done it, but you brought it to another level.

[aquataur]

Thank you very much.
What I like about this approach is that all commodities that have been established so far, like the number set-up (using one of the calculators), are applicable.

I would not appreciate to have to resort to the guesswork of using angle masters and the like. Apart from that, I suspect a non symmetrical grind could steer and deflect the axe during the cutting, which could be dangerous.

I have done an axe before free hand, and the angle turned out to be way too acute. The axe was useless. One chop and it had a huge dent.

I looked up Rick´s job. I like the laser bit, I will get one of those one day.
Good stuff too. I have never seen one of those axes in Austria.

[RickKrung]

...snip...
I looked up Rick´s job. I like the laser bit, I will get one of those one day.
...snip...

There has been a bit of discussion of the "laser line module" in the past.  Might be worthwhile doing a search here.  I no longer use one. It crapped out and I've I get along just fine without it. 

Rick