Lathe open segmented bowl index wheel 18x2

An index wheel for woodturning 18x open segmented bowls. There are two rows of 18 holes, with each row offset by half, to allow for layering of the segments.

Glue them to a ø200 circle cut from 7mm ply as shown. Gorilla glue worked for me. My lathe has a 30mm shaft, so I used that for the centre hole in the ply (30mm x 3.5TPI). It's easiest to drill the centre hole and mount it on the lathe, sandwiched between the chuck and shaft shoulder, then turn it down to ø200mm.

Three prints are required. Use the aligner segments to complete the circle, and they can be discarded once the glue-up is done.