Center marking small stock

[mklotz]

There are numerous ways to find the center of a piece of stock, but many of them aren't well suited to very small (< 0.5") diameter stock. My simplified methods...

Find circle center without a compass

Easier center finding technique

aren't well suited either.

Today I needed to find the center of a ~0.25" diameter bamboo rod so I could hand drill it to make a sheath for a sharp pointed continuity checker that bit me when I reached into the tool tray. Now, I could have gone out to the garage, backed the car out so I could get to the lathe, mount the 3jaw chuck, chuck it and center drill it, and move the car back into the garage. This isn't a high precision task so there must be a simpler way.

It occurred to me that, if I had something about the same diameter as the bamboo and with a point I could rig something to keep them aligned and simply hammer the thing into the bamboo to make a centered mark. Transfer punches have (centered) pointy ends and come in a variety of diameters.

The picture shows the setup. The bamboo and an appropriate size transfer punch were held in a V-block with the bamboo backstopped by a heavy vise. A quick hammer tap on the punch and, voila, a TLAR center mark in the bamboo.