Will Aldridge
Well-Known Member
Hey guys, been working on the motor mount design for my plane. For those who don't know its a single seat Mazda rotary powered sport plane.
Paul Lamar sells the motor mount plate shown below, and he provides the cad drawing of it for those wanting to hang a rotary on the front of their plane.
My aircraft being single seat is a little too narrow for this design. So I've gone about modifying it to suit my purposes. Had to move the starter, and the other main difference is that I rotated the rubber bushings so instead of the long axis of the bolt that goes through being vertical it is now horizontal. The CG of the engine/PSRU/prop combo is roughly right at that plate so I doubt I'll be introducing any interesting loads into those bushings, but I thought I'd run it by you guys to see if there are any gotchas that I'm missing. BTW I did see a similar design for I believe it was a Rotax engine, and that's where the idea came from. Note I didn't finish modeling the mounting plate just in case the whole idea was a bust therefore the holes in it underneath the starter.
Also wondering if the mount tubes are properly triangulated? Meaning do I need a third tube going to each of the mounting points in the plate? Or is there anywhere else that it is obviously deficient? Getting set to run some numbers on it but didn't want to beat my head against the wall if it was an unsolvable problem using standard methods.
Paul Lamar sells the motor mount plate shown below, and he provides the cad drawing of it for those wanting to hang a rotary on the front of their plane.
My aircraft being single seat is a little too narrow for this design. So I've gone about modifying it to suit my purposes. Had to move the starter, and the other main difference is that I rotated the rubber bushings so instead of the long axis of the bolt that goes through being vertical it is now horizontal. The CG of the engine/PSRU/prop combo is roughly right at that plate so I doubt I'll be introducing any interesting loads into those bushings, but I thought I'd run it by you guys to see if there are any gotchas that I'm missing. BTW I did see a similar design for I believe it was a Rotax engine, and that's where the idea came from. Note I didn't finish modeling the mounting plate just in case the whole idea was a bust therefore the holes in it underneath the starter.
Also wondering if the mount tubes are properly triangulated? Meaning do I need a third tube going to each of the mounting points in the plate? Or is there anywhere else that it is obviously deficient? Getting set to run some numbers on it but didn't want to beat my head against the wall if it was an unsolvable problem using standard methods.
