The K-Max housings are cast from ZE41A-T5 (AMS 4439) magnesium alloy and machined to accept 4340 CEVM (AMS 6414) alloy steel bearing liners.
This information is from 'K-Max Intermeshing Rotor Drive System' 53rd Annual Forum Proc., AHH, 1997. I have hard copy
The Flettner FL-282 had a magnesium gearbox, as well.
The transmission assembly will be designed so as to accept the loads from the rotors, the engine, the seat (back) and the supports.
Crankshaft to point up and forward at about 70-degrees from the horizontal.
Have the expansion of the frame and the X-shaft the same so that the two pinions can be firmly affixed to each end of the X-shaft???. This may not work since the temperature of the X-shaft and the frame may vary at different rates.
If the X-shaft is made from steel, then consider having the triangular frame produced in welded steal tubing. Then have the weldment heat treated, tempered, normalized, annealed, whatever, so as to remove the stresses at the welds.
