Finished drilling all #40 pilot holes and clecoed complete assy. Updrilled with 1/8" bit instead of usual #30 because of issues related to the batch of rivets provided. Apparently many builders have had the rivet mandrel break above the head surface. One Sonex suggestion was to us a #31 or #32 bit for a closer fit. Tried to get a rivet to go into a #31 hole. May work on thin material if really forced considering the rivets are about 0.124 and a #31 is 0.120". The .125" bit seems the best choice. The rivet goes in easily and I didn't have any mandrels break above the head. Used minimum pressure on my rivet gun, sometimes took 3 or more seconds for the mandel to break off.
Before riveting, I confirmed that all components had a proper fit and were satisfactory to close up the structure.
The rudder is complete except still need to install 3 rivets that are close to the rudder horn. RV has a small wedge that is used between the rivet head and the gun to give a straight pull with the gun at an angle. Need to borrow one from a local RV builder.
Don't know what goes in the 3 vacant holes on the rudder horn. I suspect some bushing go in those that are detailed on the control drawings, which I don't yet have. Would have been easier to drill those out while the horn could still be put on the drill press.
