October 27, 2011
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Cables and Pulleys
The next step was running the aileron cables and pulleys. There was no information in the plans as to the location of the pulleys on the front spar; only limited drawings of the rear spar pulley. Gathering info for the pulleys proved to be very frustrating. I tried many locations and gathered pictures from other builders before finally coming up with this set up. I used 3/16″ poly rope to simulate the 1/4″ cable that will be used in the final installation. The difficulty was making sure the cables did not very more than 5 degrees off the plane of the pulley. I fabricated a bracket with a slight bend to angle the upper pulley and that achieved the correct angle so the cables would run correctly. The picture below shows the final set up followed by close ups and different angles.
The next two shots are of the bracket I made to angle the upper pulley on the front spar. I used .090 4130 to make sure the cable tension would not deflect the bracket.
The following are some other shots showing various angles of the pulleys and the run of the cables.
This next picture is a view from the top of the front spar looking down.
Side view from inside the wing next to the “N” compression strut.
This shot shows the rear pulley over the rear spar; the cable clears the spar through the full range of the aileron.
The next step was to make the aileron stop bracket. I first made a stock aileron stop but that didn’t work with the aileron horn that I made for the wood aileron. I decided to make one that was easily removed with two AN3 bonts and flat brackets rather than the 1/2″ tubes as shown in the plans. The new design worked out well to establish the 17 degrees of travel up and down for the aileron.
Finished aileron stop without the aileron installed:
View from the underside with the aileron installed and the lower stop ground to match aileron horn.
Top side view of the stop with the aileron installed:
This brings me up to date on my wings. The next step will be to build up the second wing to this same point. The second wing is currently hanging from the ceiling. I will need to build the second flap and aileron (parts all ready to assemble) and to install the hangers and other hardware. This should go pretty quickly as all the parts are made but more importantly I don’t have any R&D to do on the second wing. My next new step will be to fabricate the fuel tank and mounting hardware so I can then cover the leading edge of the wing with ply to finish out the wings. Getting closer every day!
