After having studied all the plans carefully (all 5 of them now), I discovered an amazing fact:

The grid size of each plan increases almost exactly (< 1/64" deviation) in 1/8" increments!

In other words, the grid size of each plan is:

1) Picorare (Tipo 10): 5/8"
2) Nanorare (Tipo 20): 6/8" = 3/4"
3) Mirare (Tipo 40): 7/8"
4) Tiporare (Tipo 60): 8/8" = 1"
5) Merare (Tipo 120): 9/8" = 1-1/8"

I'm not sure about divine intervention but that sure as heck surprised me!! [X(]

These scalings practically follow the golden rule... even though that was never the intention.

Pete,

After looking at the 120 plans I thought... what a beast! Do let me know if you get going on one of these. An OS 91FX or 120AX or even an inverted YS 120-140 would make interesting power plants.

Anyone else out there building one of these beauties in wood?

A couple of pics to provide inspiration...

David.