Paul,
Have you done a drawing for a RV-10 Motor Mount before?  I just
returned from the EAA SportAir TIG Welding class in Griffin, GA this
weekend and have been doing a lot of practicing on my Lincoln Invertec
V205-T AC/DC tig welder in preparation for building a mount to couple
my 20B to the RV-10.    I have Jeff's adapter plate and will be using
Tracy's RD1-C.

Don

Yes here is a 3 rotor version using the schertz beam.
I'll redo if for Jeff's motor plate shortly.

Paul Lamar