Tonight I started riveting the side skins onto the aft fuse. I started with the longerons, where I could use my squeezer to set all the rivets. To assist with alignment, I packed up the front edge of the yoke, one for the bottom row of rivets, and a larger pack for the top row. This worked out nicely and everything set well. I did both sides, except for a few rivets down aft where I plan to leave things open until I have the aft bottom skin riveted on.
Today I fiddled around with the aft skin, and finally managed to get everything to fit just right. The challenge was deciding how many spacers I needed to fit between the tail wheel mount bracket and the bulkhead to which it is bolted. Vans supply 3 of these shims made from two thicknesses of aluminum. I started with all 3, and ended up needing just the two thinner shims to get a perfect fit. I used fresh bolts, washers and nuts, as I’ve attached and reattached these parts several times now. My torque wrench isn’t quite up to the task, as it maxes out at 80 inch pounds, whereas I need 85. Additionally, being a beam-style, there’s an access issue getting to the nuts. I’ve ordered a new tool, should be here on Friday.
I riveted the aft fuselage to the aft bottom skin, and then to the tail wheel mount. 10 rivets in total, all squeezed with a variety of yokes.
Green touch up primer on the mount, and splotches of white on the bulkhead makes everything look messy. The iterative process of shaping these parts to fit well scratched off primer and powder coating, so a touch-up was needed.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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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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.
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.
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.
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.
I ran the wiring harness and phone cable, then carefully clecoed on the left side skin. Then I carefully rolled the assembly 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!
