Motor mount shimming

[Bryan Cotton]

Did you guys have nice symmetrical shimming for your mounts? I do not and am wondering if I have built a banana or something.

[ScottM-Sonex1629]

No I think you built a boomerang!

My shims are not even at any of the four corners. I do remember measuring the position in relation to the fuselage to match the plans dimensions, then filling the gap as needed between the mount and the fuselage angles. I wanted to make sure I didn't compress or stretch apart the motor mount frame.

I'm sure there are some other pictures on my photobucket account, but this one shows the shims for one side taped to the fuselage while I was finishing the deburring for the mounting screws.



Good luck!

[pilotdriver]

I built my mount and have a .090 shim at each corner. still good with no cracks after 16 yrs.

[wlarson861]

I have different thickness of shim top to bottom but each left right pair are the same thickness. This ensures the mount is centered.

[peter anson]

I not only have uneven shimming, I had to make one shim that is tapered diagonally. I think your problem is that the engine mount is a bit wonky. One of my friends even had to fit his axles at different heights because the angle of the landing gear legs is different from one side to the other. It wouldn't matter much on a Sonex but he is building a Xenos.

Peter