This is the build log for Sonex Onex Serial #132, documenting my journey building a kitplane. This is a non-quickbuild version of the kit. Rough estimate to my first test flight is spring 2021.
Build Night Canceled August 28
Tonight’s build is canceled.
Inboard Wing Work
Build Night: Worked on puzzling out the next steps for assemblig the inboard wing. This area is complicated as it involved more than just getting the wing ribs in place and riveting on the skins. There are a number of moving parts and pieces for the wing folding mechanism. Had trouble identifying some of the parts on the pain spar, in particular one pin. Going to follow up with Sonex/other builders on this.
To keep going, we at least got the outermost inboard wing rib, the one with the paddle assembly for joining the ailerons installed on the port and starboard sides.
Inboard spar hinge - trying to find this on plans
Inboard spar hinge
Starboard Inner Wing Paddle Rib
Starboard Inner Wing Paddle Rib
Port Inner Wing Paddle Rib
Port Inner Wing Paddle Rib
Rear Spar Inboard Attach Bracket Assembled
Finally worked through all the issues with the bracket. I made some notations on the shorters bolts needed, and the shorter machine screws. The shorter bolts I had on hand, but I did not have the shorter machine screws. My build mentor and friend Ross walked me through the proper way to cut down machine screws, so my belt sander got a workout tonight.The brackets are now installed. Now we can go on to built out a fixture to make sure we place the ribs and wing fold mechanisms are properly leveled horizontally and vertically. Then we can finish skinning the inboard wings! After that on to the canopy fitting, engine, and electrical!
Modification I Made to Plans
Modification I Made to Plans
Measuring Parts
Measuring Parts
Fabricating Parts
Fabricating Parts
Rear Spar Attach Assembly Installed
Rear Spar Attach Assembly Installed
Rear Spar Attach Assembly Installed
Rear Spar Attach Assembly Installed
Onex Mentoring
I have been stalled on the build for the last two months out of frustration with some possible errors in the plans, some family emergencies, and events like Oshkosh. A friend and neighbor knew someone who had built (and sold) a beautiful Onex, and kindly arranged for him to fly over to my hangar and discuss very concerns I had about the build. I got the answers I needed to move past the issues with the read spar inboard bracket. Build nights are resuming on a weekly basis.
Inboard spar attach assembly
S36 screws did not arrive for build night. Cut down S38s (that were labeled incorrectly as S34) to S36. Ross mentored me on how to properly cut down the screw and measure using a belt sander. Began to reassemble the structure. Photos to be added.
Tailwheel
Bigger Tailwheel installed
Finished re-assembly of the 6 inch tail wheel with assistance of Ross Gressley. Tailwheel back on the plane this morning.
Inboard paddle assembly
Work on the inboard paddle assembly tonight. Noted that the plans call for two screw sizes that don’t make sense (one so short it can’t catch the lock nut on the thread and have any showing, the other has 5 threads showing. Measures the S32 and S34 screws and noted they are actually much longer/shorter, and don’t match the labels on the bags. Disassembled and filed the opening for the paddle as it was catching a bit on the edges and we couldn’t get it to tighten down flush. Will need to order the proper screws this week and reassemble before next week’s build night.
Photos to be added
Rear Spar Placed
Three EAA 309 chapter members helped with the build tonight, two flying in from nearby Lake Norman Airport (14A) by helicopter. Filed a rear attached bracket for the spar. Also filed the hole for the spar to fit through the fueslage slightly so the rivet heads could pass through. Removed the seat pan to get to the control cables running to the tail. We had to remove them to place the bracket and then run the cables through the spar. For now the spar is held in place paritially with a few bolts and clecos. Hopefully next we we can reassemble and rerun the control cables and reinstall the seat pans. First we will have to remove the clecos from the floor of the plane below the rear spar to cleco it in place (the we can rivet the floor skin down).
Filing a spar attach bracket
Removing the Seat Pan
Removing the Seat Pan
Disassembling the control cables
Disassembling the control cables
Sliding the Rear Spar into Position
Filed the corner of the spar hole in the fuselage
Rear Spar Placed
Rear Spar Work
Spent several hours work with my friend Ross on the rear spar. Riveted in one of the doublers, and worked on the one of the wing rib attachment assemblies. Discovered a possible plans error on page W15, it calls for a 1 inch screw, but that seems two short as it does not allow for 1 1/2 threads to be exposed above the nut. Looks like it needs 1 1/8 inch screw. Will post on build forum and contact Sonex about it.
Rear Spar Doubler Diagram 
Doubler in Spar Channel
(not riveted)
Doubler Clecoed and one rivet in 
Shan riveting the doubler 
Doubler Rivets in Place 
Diagram for Spar attach assembly 
Assembly bolted onto rib, some clecos holding portions in place
Rear Wing Spar Work
Worked on the rear spar attach brackets, forks, and blocks. Lost of checking and double checking the plans. Page W15 had some issues with perspective for the brackets. Finished fabricating them. Drilled them out and they are almost ready for spar attachment. Needs some light sanding on one fork.
3Hours
