iPart Beginner

[spackle42]

This post is a slight tangent from my previous post about O-Rings.  jhagarty offered a metric o-ring ipart, but I've realised that I need JIS B2401 parts, so I've decided to create my own ipart that can be displayed either as supplied or appropriately deformed based on the groove type.  My research leads me to conclude that I can't use text variables, so what I'd like to set up is this:

A multilevel table.  Top level is the groove type (face, piston, triangular).  Next is the nominal ID, then the cross section.  With these three pieces of information, I should be able to calculate the standard deformation which will define the correct cross section shape.

Can someone please point me in the right direction with regards to the table layout? I've attached my initial attempt and also jhagarty's ipart which has a multilevel table similar to what I'm trying to achieve.