SonexBuilders.net

For those of you that have fabricated a motor mount for your Sonex, or any other aircraft, how did you go about deciding on 4130 tube diameter and thickness? Professor Google hasn't been very helpful. I really need to find my Bingelis books. TIA if anyone can point me in a better direction.

If you can find someone local with a set of A model plans those plans show all the details needed to fabricate the aerovee and jabiru mounts. The B model dimensions will be a bit different but it would be a good starting point.

kmacht wrote:If you can find someone local with a set of A model plans those plans show all the details needed to fabricate the aerovee and jabiru mounts. The B model dimensions will be a bit different but it would be a good starting point.

Thank you


Now....
Where is Bryan....

This is probably not much help, but I did this recently for my Waiex. I ran a stress analysis and overdesigned mine. Full disclosure, I am not flying yet and I have departed way away from the recommended engine options.....I am using mainly 1 and 3/4 inch OD tube with wall thickness from 0.049 to .065 depending on the location. The exceptions are two parallel bars next to my engine and the landing gear legs, which are larger diameter.

Keep in mind jabiru mount offsets the nose gear so if you need some clearance that is an option, the Motor mount page includes what loads you need to meet for the motor mount so you could work backwards from that page in the plans depending on your engine selection.