Hey, Paul.
I have made a basic disassembly of the RD1-C in preparation for the lightening
process. I have measured the wall thickness supporting the ring at .600". If I
recall, your recommendation was to cut out .500"? That would leave only .1" of
support for the ring. Just checking before we start cutting that that is enough.
Also what would you recommend for the resulting flange depth?
I will apply the same numbers to the supporting base ring?
I notice in the drawing showing the "PT-6" style torque meter, did you spec a
part number for the torque meter? while I'm in here that would be an interesting
and useful addition.
Thanks for your help.
C. Smith

If you do a stress check .1 inch wall certainly looks like enough
but if the sand casting is less than perfect that might be
asking for trouble.  Use .2" to be on the safe side for both the
wall and the flange.

The torque meter is built in to the helical sun gear.
There is a axial reaction force on any helical gear.
This reaction force is directly proportional to the torque
the gear is transmitting. One way of measuring it is
with an annular hydraulic cylinder. The same thing is now
used to disengage manual transmissions. The space in there
is limited so it probably must be custom made.

Here is a better 3D on the subject.

Paul Lamar