3 point (scribing) centre punch

[Philip Davies]

I downloaded a pdf copy of “Modern Toolmaking Methods” ed. Franklin Jones, published 1915. On page 49, there is a photograph of a tool which can be used to centre punch where 2 lines at right angles intersect. The 2 points slot into one scribed line and the third point is moved along the work until it engages with the line scribed at right angles, “ with an audible click,” I read.

I have balked at the cost of an optical punch, but I thought that this was a good tool to have. But was unable to find one, even in a 1935 catalogue.
Of course this is not up to the accuracy needed for making accurate jigs, relying on it does on pegboard and those little brass buttons which you see. These buttons have been salvaged from telescopic frames, such as walking aids. They are attached to v-shaped springs inside the aluminium tubes and engage with one of a series of holes. I have kept them to use as dowel markers. These happen to be 1/4” diameter, same as the pegboard. I drilled 3 of them through as a tight fit on these hardened picture-hanging nails and the central one, the punch, just slightly larger, to make a single light mark, to be enlarged subsequently.

I have kept a square of pegboard around for many years since it’s handy to locate a point to drill holes in 4 corners.

I hope you toolmakers might like to make a precision version. The book is free to download, and very interesting. Other old methods may have been forgotten, but might save from buying an expensive tool.

Happy New Year.