The Final Push Begins

I really want to fly to Oshkosh next year. That means finishing and flying the plane by the end of this Spring. I have completed the airframe and am doing the 1,000 small tasks that comprise the completion of the various systems in the plane. There is a lot of truth to that old saying, "90 per cent done, 60 per cent to go". I have also been very busy at work, with family, etc. and have been putting every spare moment into the plane. As a result, no blogging. Here are some notes on what I've been up to since my last entry. I hope the photos help those getting to these various tasks.



The fuel lines are installed at the firewall. This was a lot of head scratching followed by a lot of tubing bending and flanging. I have to say that by this point I'd gotten the knack and hardly scrapped any tubing. Still, this little project took a while.











The rear section of the keel is completed after installing trim motor, bell crank and assorted hardware then bonding to floor with structural adhesive.













The aileron torque tube is installed. This involved an unpleasant Saturday morning. I think I'm precision measurement challenged. Don't ask about the extra hole in the back of the tube. Just let me say that adding a 1/16 index hole rather than relying on measurements from a Sharpie is an EXELLENT idea.







I installed an auxiliary com antenna on the side of the fuselage. I will add an "aux com" jack on the panel into which I can plug my handheld in the event of a com failure.











Rudder conduits installed! Duct tape in place, tack with 5 minute, then use a ziplock bag to put on microballoon fillets and add one ply of bid then peel ply. You can say it quickly but it is a long evening bending over inside the fuselage.









Cable and bushings attached to rudder pedal assembly.













Here is the static port tube. I hollowed out the cavity, bonded the aluminum line in with micro. Then I drilled one 1/16 inch hole through the center from the inside. I confirmed with an inclinometer that the tube was level. Then I measured the other two holes spacing on a vertical line on the outside of the fuselage using the first holeand a line from the inclinometer as a guide. I drilled those holes from the outside in and, voila!, they appeared on the inside in the center of the tube. I then filled the cavity and holes with micro balloons and two plies of bid.



At the top of the frame you can just see the mounts for the glare shield.












Obviously, the steel pins from the door don't extend out of the bottom of the receiving tubes so that they could trip the microswitches. The fix is to take a length of plastic venetian blind rod and stick it in the tube. It is light enough that it won't trip the switch on its own and it slides freely up an down in the tube. Next step is to mount hard points for the microswitches using the rod to determine the position for the switch below the receiving tube. First a cavity for the switch was hollowed out with a Dremel.




You need to install hard points for the micro switches on the door latches. My initial plan was to fill the cavity with flox, let it partially cure, then press the hardpoint in until it was in the right spot. That was a gooey mess and had to be laboriously swabbed out with solvent. I then hit on the idea of bonding the hardpoints onto wooden popsicle sticks and gluing them to the fuselage first to fix them into the correct spacing and alignment. That worked great! Here is the high tech assembly before installation.




The easy way to hold them while they cure.













Now it is a matter of fitting and filing the wooden spacer to get the correct angle and spacing to get the hardpoint and switch in the perfect place to receive the plastic rod when the door is closed. It will then be fixed temporarily in place then bonded permanently.








Here is the hardpoint on the copilot's side with the popsicle support bonded to the side with 5 minute epoxy.











Here is the switch taped onto the hardpoint and taped in place while the 5 minute epoxy bonds the popsicle stick to the fuselage. This will leave me with the hard point at the perfect height and orientation for the switch so that I can then permanently bond it in place with epoxy and flox.








Here is a top view of the switch showing the conduit access and the duct tape and popsicle stick dams to keep the goop in place. I used a disposable syringe to inject it behind the top and bottom of the spacer until it squeezed out of the gaps then Qtips and alcohol to clean and smooth. Note the hole in the top of the conduit for the wires. Make sure to use a dremel to make the holes. A drill could (theoretically) drill right out the bottom of the fuselage before getting access to the conduit.



Here is the finished product. The goop is cured. I used West 404 High density adhesive filler. The hardpoint was then drilled with a #43 drill bit and tapped 4-40. Then a plastic rod from a venetian blind was used as a spacer in the receiver tube to trip the switch when the steel pin from the door entered the tube.








On the right is a top view of the finished assembly. Note the hole for the wires and the cool polished receiver plate. All that's needed now is to fabricate a 3 bid cover for the hole and the switch.










Here is the final product with duct tape over the form to create a 3 bid cover to protect the switch under the carpet.