Wednesday, July 13, 2011

Catching Up With Controls

After closing up the fuel tank and still waiting for the sealant to fully cure, I caught up with the installation of the control elements.
The first step was to trim the blocks that would hold down the flap handle.


Before installing the flap handle I realized that going further back in the tunnel to install the flaperon pushrods the still installed turtle deck skins would make access unnecessarily hard, so I removed them.


Back to installing the flap handle. It turned out that it was easier to install the flap handle and the flaperon mixer at the same time as they are connected.


I noticed that the sticks were not quite aligned and straight after connecting everything to the mixer. The right stick appeared to be ok but the pilot side was pointing outboards when supposed to be in straight and level flight. I even sat in there to verify that this wasn't an optical illusion. I had measured the pushrods and set them according to the plans. I decided to adjust this a little as I didn't like the look of it. This took quite some time but I ended with 3 full turns longer than I had the pushrod measured before. The whole adjustment process was a bit awkward and mostly guess work, because the sticks move when the flap handle is actuated. It must be coming from the radial movement of the mixer which is supposed to the a linear one. I wonder how this will feel in flight. Here's a better shot of the flaperon mixer.


Installing all this took around an hour as accessibility was close to ridiculous with the fuselage on its belly. I decided to turn the fuse on its side for the next steps. With the tail cone attached, it is significantly harder to turn the fuselage on its side but it's still manageable.
When I wanted to slide the flaperon pushrods into the tunnel I realized I had made a building mistake. The roll servo was already installed and torqued into place which prevented me from getting those dang long pushrods into the tunnel. The only possible access point is through that cutout in the back of the cockpit floor that was blocked by the servo. I removed it, cussed because of those two forward bolts that are hardly accessible and slid the pushrods in without any problem.


I put the servo back in place and cussed a bit more (about the same bolts as before). Here's a picture of the rear tunnel with the pushrods installed.


Finally I installed the powder-coated Flaperon Torque Arms and connected them temporarily to the pushrods. They will get match drilled a little later and then removed again to get match drilled on the opposite side which you can't reach with the arms installed in the plane.
Once this was all connected I was amazed how mushy and wobbly the whole control track felt. I think it mostly caused by the torque arms not having a stable pivoting point. They can literally move all 3 dimensions and so they try to avoid to go in the direction you want to go in. I expect this to go away when their counterparts are installed and the wings are connected as they will provide lateral stability for the bearing of the torque arms.


Here's a view of the whole installation area.


I just hope I don't have to take anything of this out again - ever. I am completely aware that by saying this I have doomed myself to eventually having to just do that - taking it all out again. It will probably be because of a fuel leak which I overlooked despite all the pressure testing ... Can you tell I'm in a positive mood today?

3 comments:

  1. This is why I'm so worried about the wiring changes that are promised to come with the SkyView. I don't want to take any of this stuff out again either!

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  2. Yep, that was my thought while tightening the last nut. What if ... ? At least I realized that the change of the pitot tube routing won't be an issue. The part of the static tube going forward to the panel can be used to run the pitot pressure back without having to pull this beast out of those tiny snap bushings.
    Had there been any unused room in those pesky bushings I would have installed some spare wires, just in case. For now, I can't see how we could add any wires that run the full stretch from stern to bow without drilling.
    Are you going to OSH this year? Try to squeeze some unofficial info out of them about the wiring when you're there. I rather see the train coming before it hits me. Not that it would make a huge difference, but still ...

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  3. No, I'm not going to OSH, but I figure we'll find out from others that go.

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