I went through the calculation for the front shaft using an online java
calculator here:
http://www.tech.plym.ac.uk/sme/desnotes/shaftMandT.htm
The attached screen shot shows the result of the calculator and would

indicate that the front shaft is indeed capable of taking the full torque
pulse of a 2 rotor, even if you add a significant fudge factor.
If you only ask it to take ½ the load?  Dual prop amphibian?
Decker, Michael

What stress level or material did you enter the program with?

Paul Lamar
UTS 800 Mpa
Decker, Michael


800 megapascal = 116 030.190 41 pounds per square inch Nobody designsa
crank shaft or e-shaft to run at 116,00 psi.

19 mm is a 3/4" diameter e-shaft. That is crazy :)

Yes it might not break if applied once but no engine designer would usethat
number. 30,000 is more like it.

Paul Lamar

Even using 206.842(30000) it still works, and that is for the full max
torque
pulse, not half load max which would be 200ftlb.

Are you telling me that when they ask for UTS in these calculators
they don't really mean UTS?
Decker, Michael


Stop mixing and matching measuring systems. If you use foot pounds then
use psi instead of Kpa. I have to convert things and that takes time.
We got to the moon on inches... as my old friend Vance Jaqua RIP was fond
of saying :)

No but engineers don't always design things to ultimate tensile strength.
There are fatigue and deflection considerations.

If you want to try this be my guest. It is a free country. Just
please don't kill your self in a rotary powered air craft.

I don't want to waste any more time on this scheme. There are more
productive
things for me to do.


Paul Lamar


It would be interesting to me to consider why the flywheel end is
heavy and the accessory end is thinner..  What were the designers
going after?


Regards,

Matt-

It is only thinner out side the rotor loads. Weight savings
where you don't need it to drive the accessories. Also gives you a
shoulder for the thrust bearing.

Paul Lamar