Today I managed to finish all the remaining systems installs in the aft fuse. Finish is perhaps not exactly accurate, as there are still a couple of zip ties that need to be tensioned up later.
I started by completing the static install. No problems here, was careful not to create any low spots. Everything went together quickly.
Static system completedRight static port with elbow connectorRight port connector and tee connector
There are a couple of antennae cable that run through the aft fuse. One down the center of the bottom skin, and the other one, the ELT antenna, runs down the side skin and through the bulkheads via a snap bushing. Vans have been criticized for routing the ELT cable through the bulkheads, because in the event of a crash it’s possible the bulkhead could shear the cable. I’m not going to worry about it, and just followed the plans.
Installing zip ties. These stay lose for now to accommodate future wires All of the systems; rudder cables, antennae cables, “phone cable”, and wiring harnessWiring harness secured to j-channelAll systems installed!
Today I ran the rudder cables up through the aft fuselage, attached the cable guides, and installed the two static ports. I’m going with the Cleveland Tools static port kit, as I’ve heard these are worth the $50 investment.
Before running the rudder cables I countersunk the nylon cable guides, and installed a bunch of bushings for the various systems that run them rough the aft fuse.
Some of the snap bushings being installed in a bulkhead
Running the rudder cables was trivial, and I thought it would also be trivial to install the cable guides. Instead I ended up drilling out a pop rivet, after I stupidly pulled the entire rivet stem out of one rivet. I also ran into trouble with my pneumatic pop rivet puller; it wasn’t always breaking off the stem after setting the rivets. I ended up with everything installed, but some uglier than desired looking rivet heads.
Rudder cables. Feels strange to put something so heavy into the airplane, but also fun to be installing some systems!Left rudder cable installed. The cables cross overOutside view of cable guidesInside view of cable guides. Washers give the rivets something stronger than nylon to pull against when setting
Next up were the static ports. The standard Vans static system uses a pop rivet with the stem removed. Some builders from my EAA chapter reported having issues getting the static line to stay on the rivet and recommended the Cleveland static kit. The Cleveland kit has a pair of nice looking ports, uses red static hose, and has some really nice connectors that grip the tube firmly, and provide a quick removal.
First I stepped drilled the standard holes out to 1/2 inch.
Using the step drill to upsize the hole
Then I carefully cleaned and preped the hole, and used some silicone adhesive on the surface of the port. This was then pressed into the hole from the inside.
The finished port looks good! 24 hours and this will be ready for the rest of the system install.
One of the two ports installed (one of each side of the fuse)
Today I did a final round of fitting and then drilled the two keeper holes from the aft bulkhead into the tail wheel mount. Then I primed the aft fuse bottom skin and shims.
Drilled and countersunk the keeper rivets holes. This is where the tail wheel mount attaches to the aft bulkhead
There is a slight twist in the bulkheads and the tail wheel mount doesn’t quite sit flush against the aft bulkhead. After checking with Vans, this is common and due to the sandwiching of pieces used to make up the bulkheads. With a little hand pressure, I was able to straighten it out and drill the two keeper holes. Then I countersunk them on the drill press. I was disappointed in the quality of the three fluted countersink after using the single fluted sink on the longerons. I need to buy some more countersink cages, and a couple more single fluted sinks.
Primed the aft bottom skin, shims, tail wheel mount, and touched up the bulkhead
I decided to prime the outside of the aft bottom skin, as it had been scratched up in the trimming and drilling process. I may regret this at some point in the future, but it seems like the right thing to do for now.
I also cleaned, dried, and primed the inside of the tail wheel mount using some green self-etching rattle-can primer.
The last couple of days I’ve spent a couple of hours trimming the aft most bulkhead. To clear the weld on the tail wheel mount, I had to file down the bulkhead cutout a surprising amount. It now sits flush against the flange of the tail wheel mount, and the bottom skin cutout fits nicely around the mount also. This weekend I’ll drill a couple of holes and countersink then, then touch up the primer.
Aft bulkhead now clears the weld bead allowing tail wheel mount to sit flush against the bulkheadBefore and after trimming the aft bulkhead
Aft bulkhead needs trimming to clear the tail wheel mount
Today I test fit the aft bottom skin, aft bulkhead, and tail wheel mount. The bottom skin cutout was pretty close, needing just a small enlargement to clear the tail wheel mount. The aft bulkhead needs a bit trim so the skin and contact the bulkhead flanges, and the weld bead can clear the bulkhead. I spent a couple of hours assembling, disassembling, trimming and repeating before it started to fit well. I still have some more work to go before this is final.
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Shims will be needed to close this gap
I will need to use some shims to close the gap between bulkhead and mount. Right now the gap is large, almost 1/8th of an inch. This is in part due to the weld pushing on the aft bulkhead, keeping these apart. Will be interesting to see how many shims/spacers I’ll be up needing here.
Need to trim the bottom skin to match the template
Today I cut out the aft bottom fuse skin template from the manual, and marked out the areas a needing to be trimmed. I found that taping the template to the outside of the skin resulted in good placement, and some masking tape held it in place while I drew out the area to trim.
Trimming the aft bottom skin
I used a variety of tools to make the cut, a handsaw, bandsaw, vixen file and small files like the one in the picture. I was happy with the way this turned out.
Tonight I hit a milestone, as I clecoed on the side skins and rolled the aft fuse right side up. It’s great to have a major part of the fuselage taking shape!
I started by reading up on the systems that need to be laid out in the aft fuse. There are a number of wiring runs that need to pass down one of the left hand j-channels between the side wall and the bulkheads. It’s much easier to do this before putting the side skins on, so I studied the diagrams to understand it all. I identified that one of the wires shown in the plans was not in the wiring harness, but I went ahead anyway. [edit] I’ve since confirmed with Vans that the wire has been deleted from the plans.
Highlight shows the missing wire in the plansC410P with missing wire. This is the correct configuration according to Vans Aircraft
I didn’t attempt to use the wire ties at this stage, and instead used a little masking tape to hold the wires in place while getting everything set up.
J channels and longeron installed on the left side. These are loosely held in place with tape while I ran the wiring
I ran the wiring harness and phone cable, then carefully clecoed on the left side skin. Then I carefully rolled the assembly upright.
Wiring runs installedLeft side skin clecoed on, after rolling upright
Once upright, the right j-channels and longeron can be installed, the aft bulkhead (#11) clecoed on, and then the right side skin is clecoed on. With both side skins on, you can really get a sense of the size of the airplane. The longerons extend forward, and diverge from each other at surprisingly wide angles. The bulkheads sit tall and highlight how much space there is going to be up forward. The cockpit will be wide and tall… this thing is big!
This aft fuse section occupies a surprising amount of spaceSide skins on, starting to look like a real airplane!
Last night and again today I spent a few hours dimpling the side skins. Doing in one session would have been faster, but each time I started I got interrupted. In any case, I rigged up some extensions by placing some sheets of particle board cover with carpet on boxes, and strapping them down with tie downs. I was able to adjust them a little to ensure I had the right support. The holes on the curved edges were the most difficult, but I found a way to make it all work.
