RivetBangers.com

flat mating surface for aft spar. no single washer required to provide offset. may increase torsional stiffness of the vertical stab aft spar slightly. these are important bolts to check torque on the annual inspection list. in my opinion, adding a single washer between flanges is not good basic mechanical design. bolted flanges should always be flat and parallel to each other, not at an angle. a bolt applies thousands of pounds of load, the mating surfaces need to be flat.

max speed during Vmo testing = 192 ktas, rock solid. light rudder paint, light weight rudder trim wedge and light weight strobe (major players because these are at the trailing edge), no glassed-in end caps, built to plans (additional glass adds weight) .... and faired rudder cable attach bolts (no vortex shedding from fasteners, minor effect).

and never a loose jam nut in 9 years (since new) because they are installed with Loctite or maybe superglue. loose jam nuts may be a factor for flutter. so far, I am very pleased with this rudder.

https://youtu.be/2LhFZwankY0

Personal Space, Yotto
https://youtu.be/l-KSATZTi_4