Page 1 of 1

Rotax Engine Mount Attach Bars

PostPosted: Tue May 12, 2020 3:17 pm
by Zack
Has anyone used the Aeroconversions Rotax Engine Mount Attach Bars with the Sonex provided Rotax motor mount? How did you install the attach bars?

I made a beautiful pin using the AeroVee mount pin specifications http://www.aeroconversions.com/images/products/SNX-P31-03_AeroVee_Mount_Pin.pdf, only to find it doesn't apply to the Rotax mount. The mount pin is a 4130 steel tube with a washer welded in the middle. One side is then welded into the motor mount and the other side the shock absorber rubber bushings sandwich the attach bar. On the factory Rotax mount half of the tube and the washer are already welded and powdercoated in, but it terminates at the washer and there is no tubing for the rubber bushing and attach bar. Furthermore, the length of tubing for the bushings and the attach bar differs between the AeroVee and Rotax.

I made a steel bushing out of 4130 steel tube the length of the shock absorber rubber bushings and attach bar stack, then bolted it together with an AN4-60A bolt. This is a two part solution instead of the one part solution in SNX-P31-03. The weight of the engine will be carried in shear on the AN4 bolts only and not the 4130 steel tube welding into the motor mount. Thoughts?

Re: Rotax Engine Mount Attach Bars

PostPosted: Thu May 14, 2020 12:50 pm
by SonexN76ET
Image

I mounted my bars similarly to that shown in AeroVee manual for the engine mount. I put fender washers on the two outside ends of the rubber bushings as suggested by Mike Smith on his AeroVee to present sagging or distortion of the bushings.

Jake