It's time to start work on the fuselage.
The first section in the fuselage plans involves assembly of the mid fuselage bulkheads. After locating all the parts required, I started working on the first of the four bulkheads.
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| All bulkhead parts located, and ready to be worked on. As always, I debur all edges of a part before I start working on it |
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| First steps involve creation of two stiffener angles that will be attached to the ends of the center section bulkhead spar |
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| Angle is clamped flush with the end of the center section bulkhead spar... |
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| ... and match drilled to #30 |
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| Match drilling in progress, using a drill stop to minimize chances of any mishaps |
Next various nutplate screw holes in the center section bulkhead side channels were countersunk for the head of a #8 screw.
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| Countersinking nutplate screw holes for a #8 screw. Given the thickness of this piece, I used an additional piece of angle with a #19 hole to act as a pilot for the countersink bit. This resulted in perfectly round countersunk holes |
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| Countersunk holes turned out well with no chattering thanks to the angle acting as a pilot for the countersink bit |
After countersinking the screw holes, I reamed out the bolt holes in the landing gear mounts where the required bolt size did not fit through the hole. This cleared out any excess powder coating within the hole and allowed the bolt to pass through cleanly.
The reamers used were
- 3/16" for AN3 bolt holes
- 1/4" for AN4 bolt holes
- 0.311" for the lone AN5 bolt hole
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| Reaming the landing gear mount to allow bolts to pass through the holes |
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| Landing gear mount in place on the center section spar with bolts temporarily inserted to check for alignment |
The plans call for trimming the outboard portion of the forward center section bulkhead lower flange as needed to allow the landing gear mount to sit in place without interference. I found, however, that both the left and right landing gear mounts sat well within the pre-trimmed flange cutout, and no additional trimming was necessary.
Next I moved on to more countersinking.
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| Countersunk holes for #8 screws in the center section bulkhead side channels on the right... |
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| ... and the left |
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| Countersinking the nutplate attach holes in the mid seat rail supports |
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| Mid seat rail supports ready for priming |
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| Countersinking the nutplate attach holes in the center section bulkhead side channels |
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| Center section bulkhead side channel countersinking complete |
As other builders have done, I am adding two additional 3/4" wiring/conduit holes in the center section bulkhead side channels. I marked the locations for these at the same spacing as the existing holes and drilled them on the drill press.
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| Drilling 1/4" pilot holes for the additional wiring holes |
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| Upsizing the wiring holes to 3/4" with the step drill |
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| Center section bulkhead side channels with additional wiring holes cut and ready for priming |
Next, I followed the suggestion on
rv10.org to countersink the 7 outboard holes on each side of the center section bulkhead spar along the top portion of the bottom flange. These are easy to countersink by hand using a #40 countersink bit in the deburring tool (with the extension attached), and would be a pain to do with other parts riveted on as the plans suggest in section 28.
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| Countersinking holes for a flush AN3 rivet. These holes will later be under the landing gear mount so rivets will be double flush riveted |
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| Later I will put a dab of primer in these 7 countersunk holes on each side of the spar |
I then moved on to working on the aft center section bulkhead. This requires enlarging wiring holes in the bulkhead side channels (as only pilot holes were present), and I also added 2 additional wiring holes on each side as I had done in the forward center section bulkhead side channels.
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| Additional pilot holes drilled for wiring below the 2 predrilled holes on each side |
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| Wiring holes enlarged using a step drill on the drill press, and hat stiffener parts separated and trimmed |
Next I assembled the aft center section bulkhead to ensure all existing holes aligned and were correctly sized, and then proceeded to match drill bolt holes from the spar caps into the seat rail supports and side channels.
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| Aft center section bulkhead assembled and secured to workbench |
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| Match drilled bolt holes into the seat rail supports and side channels at the top and bottom of the spar |
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| Match drilling of bolt holes complete |
I then used bolts to align the center section upright bars to the spar and match drilled the #30 holes into the bars using a reamer. I did have to sand the ends of the upright bars just a touch to get them to fit easily within the space between the spar caps, as without sanding, the upright bars would have spread the spar caps enough to cause misalignment in the wing bolt holes.
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| Match drilling the upright bars |
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| Upright bars match-drilled, countersunk and labelled |
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| The final steps in preparing the aft center section bulkhead involved countersink the nutplate attach holes along the top flange of the spar |
Moving on to the rear spar bulkhead assembly, I again started by deburring all edges of the parts, and then straightened the rear spar attach bars with the help of the vise.
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| Rear spar bulkhead parts |
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| Rear spar attach bars lay flat after being straightened (except for the intentional joggle at each end) |
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| Nutplate screw holes were upsized to #19 as needed |
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| Rear spar bulkhead assembly clecoed together |
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| Once again using angle with a #19 pilot hole to guide the countersink cutter while countersinking nutplate screw holes for a #8 screw |
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| Following another tip on rv10.org, I countersunk the #40 holes on the outside flange of each bulkhead side channel to accommodate a dimpled skin |
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| Due to the proximity of some flange holes to the edge of the part, I carefully countersunk those manually to have better control over the countersink depth |
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| All parts countersunk as needed, deburred... |
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| ... and ready for priming... |
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| ...including the four crotch strap lugs |
The final bulkhead to work on in this section was the rear fuselage bulkhead. This has only a few parts that need to be prepared.
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| Rear fuselage bulkhead parts |
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| After separating the two gussets, I clecoed the rear fuselage bulkhead together and found that I had to ream the gusset-to-spar holes for rivets to pass through cleanly. Minimal material was removed while reaming. |
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| Left gusset reamed |
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| Right gusset reamed |
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| Rear fuselage bulkhead ready for priming |
Time Taken: 16.2 hours
Dates: December 9 2024 - December 19 2024
Mid Fuse Bulkheads Total Time: 16.2 hours
RV-10 Build Total Time: 890.4 hours
Priming Total Time: 104.7 hours (not included in build time totals)
