Continuing with initial assembly of the mid fuselage, I clecoed all the bulkheads to the ribs, and then clecoed the two skins in place.
 |
| Rear spar bulkhead clecoed to seat rib assemblies |
 |
| Rear seat ribs and aft bulkhead clecoed in place |
 |
| The fuselage is rapidly growing bigger |
 |
| Bottom skins clecoed to the mid fuse structure |
 |
| All holes lined up perfectly, confirming correct orientation of the parts |
 |
| Skin stiffener were then clecoed in place, again paying attention to the orientation of each stiffener according to the plans |
 |
| Right (copilot) side floor stiffeners |
 |
Left (pilot) side floor stiffeners
|
 |
| Right side rear seat ribs |
 |
Left side rear seat ribs
|
 |
| Right side baggage ribs |
 |
| Left side baggage ribs |
After clecoing everything in place, and verifying all holes that needed dimpling (which in essence includes all bottom flange holes of ribs, aft center section spar, and rear/aft spar bottom flange, except those rib and rear/aft spar holes that lie together), I took some time to think about COM antenna placement.
After much research, my plan is to install two Delta Pop Bent Whip COM antennas on the bottom of my RV-10 in the same location other builders have used (the forward section of the second inboard rear seat rib bay on each side).
To achieve this, I fabricated some spacers and doublers that will be installed inside each rib bay for antenna attachment. The doubler will rivet to the second inboard rear seat rib bottom flange, hence the need for an additional (slightly smaller) spacer to sit in the space between the doubler and bottom skin.
For the spacers, I used 0.025" aluminum from my empennage trim bundle (same thickness as the rear seat rib), and for the doublers I used 0.032" aluminum.
 |
| Two spacers and one of the doublers marked for cutting on the bandsaw |
 |
| I marked the approximate location of the spacers/doublers directly on the bottom skin. This enabled me to determine the required size as well as initial rivet spacing |
 |
| Doubler after cutting and deburring, The additional marks are for bend lines for extra rigidity |
 |
| Doubler ends were bent by hand in the vise |
 |
| Doubler ends bent, but still need some additional bend to fit |
 |
| Doubler came out nicely after cutting and bending |
 |
| Spacer fits next to the rib flange |
 |
| Doubler fits over the spacer and rib flange |
 |
| Left and right doublers and spacer ready for rivet holes |
 |
| To begin with, I match drilled the rib flange rivet holes from the skin into the doubler |
 |
| Initial 6 rivet holes match drilled and reamed to #40 |
 |
| Doubler with initial rivet holes as dictated by spacing on the skin |
 |
| The next set of rivet holes were marked to allow riveting of the spacer beneath the doubler while maintaining hole edge distance requirements |
 |
| After drilling these additional holes into the doubler, they were also match drilled to the spacer |
 |
| Spacer clecoed to doubler. I also verified that the doubler/spacer assembly fit well into the space between the rear seat ribs |
While waiting to receive my COM antenna order from
Delta Pop Aviation, I decided to countersink the holes called out in the bulkhead flanges that lie under a rib.
 |
| For holes at the ends of the bulkhead flanges, I used magnets to hold a piece of aluminum (the same thickness as the spar) next to the edge. This created a continuous flat surface for the countersink cage to rest on while drilling |
 |
| Holes countersunk for a skin dimple in the aft fuselage bulkhead bottom flange, on the right... |
 |
| center... |
 |
| and left sides |
 |
| Holes were also countersunk in the rear spar bulkhead bottom flange |
 |
| This included countersinking all holes intersecting a rib... |
 |
| ...as well as all holes intersecting a bottom skin stiffener |
 |
| Be sure to double check the orientation of the bottom skin stiffeners. It is very easy to place them the wrong way, which would then mean the floor pan rivets would not line up correctly |
Next all remaining bottom flange holes in the ribs and spars (except the aft center section bulkhead) were dimpled.
 |
| Dimpling rib bottom flange holes |
 |
| Dimpling bulkhead bottom flange holes |
 |
| Rear spar bulkhead bottom flange holes dimpled |
 |
| Holes in the aft center section bulkhead were countersunk to accommodate a skin dimple |
 |
| Aft bottom skin holes were also dimpled at this time |
My COM antennas arrived and I decided to continue working on the antenna doublers. After match drilling all the rivet holes, I 3D printed a
drill template for the antenna mount holes, and marked and drilled the hole locations through the spacers and doublers.
 |
| Hole mount template and holes marked for drilling |
 |
| Using the step drill to drill the coax connector hole through the doubler and spacer together. A 1/4" pilot hole had been drilled prior to using the step drill |
 |
| Coax connector holes drilled through both doublers |
 |
| After drilling the bolt holes, the antenna was test fit against the doublers and fit perfectly! |
 |
| Antenna doublers and spacers ready for alodining |
 |
| Doubler rivet holes being match drilled to the bottom skin |
 |
| Antenna coax connector location was also marked on the bottom skin but will be drilled later with the skin attached to the structure |
At this time, I also decided to do some work on conduit routing. After researching other builders decisions on conduit routing, I decided to route two conduits through the second inboard rear seat rib on each side of the mid fuse towards the baggage area.
I 3-D printed a
polycarbonate bushing designed by Allen Glen (also building an RV-10) which will allow me to securely route the Van's conduit through the rib at an angle while avoiding sharp bends. I also printed Allen's template that allows me to accurately mark the bushing outline and drill locations on the ribs.
 |
| 3D printed bushing and drill template. Bushing location was also marked in the ribs. |
 |
| Drilling pilot holes for the conduit bushing cutout |
 |
| Using the step drill to enlarge the cutout |
 |
The cutout was shaped to final size using a drum sander in the dremel, followed by filing and deburring. I also drilled a couple of 3/8" holes that will hold bushings for routing the COM antenna coax cable
|
The 3D printed conduit bushings fit perfectly in the cutouts. Many thanks go to Allen Glen for all his 3D print designs that are really helping me out with my build. I highly recommend his
build log as it has been and continues to be a great reference for me!
 |
| All mid fuse parts drilled, deburred and ready for priming |
 |
| Mid fuse bottom skin dimpled |
Time Taken: 15.5 hours
Dates: January 24 2025 - February 4 2025
Mid Fuse Ribs & Bottom Skins Total Time: 34.7 hours
RV-10 Build Total Time: 937.4 hours
Priming Total Time: 115.3 hours (not included in build time totals)
