Brian -

All good points.

Ring size charts are not standardized as you noticed. I built my own table years ago by averaging several charts from reference books. There is now an ISO standard for ring sizes. I can edit the .htm file to match the ring size table I use. For now the constants used in the existing script are close enough for development.

The 3D prints will be made from PLA. Your idea for a shrinkage multiplier (scaling) to be applied to each of the 3 ring solids is a good one. As you know the results would be affected by the brand of filament and the print temperature, so I would have to make some test prints to fine tune the scaling factor. A 5% scaling constant in the script is a good place to start.

The three profiles would be drawn in advance and saved in a MoI 3DM which becomes the template for running the script. I assume the three profiles can be named (via Styles) in the template file for use by the script.

If possible, a nice final feature would be to find a simple way to identify each of the three rings as nominal size, 1/4 size smaller, and 1/4 side larger. I'm thinking each of the three profiles could be supplemented with two additional profiles, so I would have profile A1, A2, A3 and profile B1, B2, B3, and profile C1, C2, C3. I could modify the outside of the profiles so, for example, A1 produces one groove in the ring OD, A2 produces two grooves in the OD, and A3 produces 3 grooves in the OD.

Ed