I did not feel like working on knives today, so I have decided to make the measuring pin from brass. It took me rather longer than I expected because I had to work out several things on the fly and there were therefore several failed attempts and repairs. But I managed it in the end and the result looks kinda cool. And it works just as well as the wooden one, in addition to being ever so slightly more precise.

The bent brass pin on the right is screwed and glued into the lower half of the pin and goes through a hole in the upper half where it has slight (several tenths of a mm) clearance.

Here you can see the upper jaw, where a ground wood-screw holds the spring tightly in place. In combination with the bent brass pin, this holds both jaws fixed against each other so the tips do not misalign (too much) when used.

On the underside is no screw. Originally I thought that two bent brass pins in the back portion will do the trick. But it did not work at all, it turns out that make something like that precise enough by hand is impossible (for me at least). When you look closely at the pictures, you will see that there are plugged holes where that second pin was. If I were making another one, I would try to ditch the guiding pin altogether and fix both jaws to the spring with a screw. Whether it would work better or not I do not know, since I stopped tinkering as soon as I got a working product.

And the second tool that I have made today is a center scribe.

It is a piece of black locust wood onto which are fixed two small ball bearings. The axes are just press-fitted both into the wood and into the ball bearings. Black locust is strong enough to hold and if it splits, I will make the body from aluminium, this was just a proof of concept.

Here you can see the other side. The wood-screw goes all the way through and just the tip pokes out between the ball bearings. Should it turn out necessary, I will eventually replace the screw with a re-ground drill bit, but for testing, a screw was a readily accessible and easily applicable piece of hardened steel.

To scribe the center on a flat bar (in the future on an outlined blade) it is simply inserted between the ball bearings so it rests firmly on both of them and on the screw tip. When dragged through (for example downwards on the photo, assuming the tip of the tang is down), the screw tip inscribes a line that is very close to the center. Not perfectly, but I can also scribe a second line by dragging the piece of steel through the assembly in the other direction (putting the tang up in the photo and dragging that way). These two lines very close to each other are sufficient enough for me to grind the blades symmetrically, after all, it is better than what I have used so far.