Weeks 67-74: Center/Rear fuselage
While waiting for the missing parts I continued fitting the controls. I mounted the rudder pedals and trimmed the control stops per the instructions to provide the required clearance. I also fit up the control sticks and the torque tubes for the flaps and elevator. I have all theses just temporarily mounted until the center fuselage is more complete. Once I am comfortable that the structure is locked in place I will make sure everything moves smoothly and rivet the brackets in place.
I also continued to work on the antenna layout. I had planned to put the ELT/ADSB antenna under the luggage floor, just behind the rear seats. During his second visit, the technical councilor suggesting moving it a little farther back to reduce the potential for radiation exposure for rear seat occupants. On his recommendation I decided to put it just behind the rudder cable tension adjustment bracket. I made a simple doubler to provide a more sturdy mounting location then drilled the holes to match the antenna.
With that mounting determined I ran the coax cable with braided sleeving to protect it and secured it in place. When I have all the wires in place I will zip tie them to the rudder cable sleeves to keep them in place and prevent interference with the controls. I also pulled the wires for the top COM antenna and the GPS. I am going to follow Midwest Cable's recommendation and place the IFR GPS on the top of the fuselage next to the parachute cover.
To prepare for the next steps once the parts arrived I also test fit the parachute box and match drilled some holes that were missing. I think I caught some parts between a design update. Once thing I was not sure of was how to dimple the holes on the angled top of the right side of the parachute box. I thought about unbending the flange enough to dimple them, then bending them back but before I did that I found a 5/32" rivet puller dimple die set that looked low profile enough to work. This turned out to work perfectly. I also got ahead on the center fuselage by cutting the insulation for the floor. This can now be glued on when I am ready.
To get ready to complete the rear fuselage, I test fit the top skins. One of them fit fine without any trouble, but the other one started to crease when I tried to bend it in place. With a little work I figured out the best way to get it properly bent around the ribs. It must be cleco'd in place starting at the top and then working down. I found that the holes for the most aft rib (that I initially had cleco'd first) were not lining up properly. I decided that if these still did not line up when doing the final assembly I would just match drill new holes in the rib.
At the end of week 72 the missing luggage floor finally arrived. I I immediately test fit it in place, then match drilled the holes for the holes to attach the four supports to the back luggage compartment skin and the holes in the side skin to attach the center support. With that done I prepped and primed the floor, then I cut and glued the insulation on the bottom.
Before I could install the luggage floor I needed to figure out the ELT mounting. Midwest Panel had suggested below the rear seats, but I couldn't find a way to create a sturdy mount that would still allow the ELT to be removed for service. I decided to move it back to the rear fuselage, just under the luggage floor. I made a mounting bracket out of .063" aluminum angle from Lowe's and some thick aluminum plate I had on hand. I think this turned out very well, it should be a strong mount and the ELT is easily accessible through the luggage door and the access hole in the floor.
The last step before installing the luggage floor and parachute box was to put in the long elevator pushrod. I got this in place, then added grease at the bushing as indicated in the finishing manual. With that done I riveted the floor, luggage extension and parachute box with any rivets that go into the parachute box or cable tray installed from the inside out as indicated in the manual. This is to prevent the parachute from snagging on the rivets in the event it is deployed.
Once the luggage area was done I cleaned up the inside of the rear fuselage as much as possible then started putting the top skins on permanently. Everything fit very well except for the rivets on the last rib on the left skin, and the bottom row on both sides when the top skins attach to the more rear bottom skins. Since the entire from section was fitting properly I just matched drilled these holes then riveted everything in place. The rear fuselage is now done and I am ready to start working on the sides of the center section.
I also recently received the 915is motor. I had been expecting to get this in the fall, so this now removes one of the last potential roadblocks. Now I am going to try and get my progress ramped back up. Unfortunately there was some damage to the motor crate during shipping. There was a plastic cover that was cracked, and the part it covered looked like it had been pushed back in towards the motor. The US factory representatives decided the best way to fix it was to ship the motor back to them in LA so their local tech can repair it and they would ship me another new one they had on hand. The first motor is on its way back to California now, and the replacement should be here in the next couple weeks with the firewall forward crate.