January 28, 2014 


I finished the wood mock-up of the fuel tank only to discover that the location of the pulleys and cables for the aileron were going to interfere with the tank straps.  I also discovered that the balance cable might interfere with the "X" brace at the top of the cockpit.  I spent most of the past week or so trying to figure out a better routing for the cables.  I discovered that The location I previously chose for the two pulleys was incorrect.  I had missed the locations in the plans for the pulleys!  After talking to another 2+2 owner I figured out how to position the lower pulley with a spacer on the lift strut attach fitting (not shown on the plans).  With that solved, I worked on the location of the upper pulley and decided to keep it where I had previously had it.  After careful measurements, I think the cable will clear the "X" brace with a couple of fairleads if necessary.  

First, the mock-up of the fuel tank.

The straps took some time but worked out good.  After fitting the tank I checked and found the possible interference of the cables.  


I drew the diagram above to see how the cables would pass the tank.  The upper cable is ok; the lower was too close to the tank and the strap prompting the re-location of the pulleys and cables. The lower cable needs to go under the strap.  With the cable located correctly on the lift strut fitting the cable would pass underneath the straps.

 

This picture shows the lower pulley positioned correctly on the lift strut attach fitting.  The upper pulley was supposed to be to the right of the lower pulley but I didn't think it would work as well; cables were very close to the "N" strut and anti -drag wires. The above gave me good clearance.

Fairleads will be needed as the cables enter and exit the tank bay tut that will be easy.  



This picture shows the cable running under the tank but above the center brace.  I'll add fairleads here also to make sure the cables don't hit the straps.  

I have a lot of finish work to do on the tank area before I can glue the shear plate on the bottom but now I can move forward without so much "head scratching" to do.  

Return to Past Posts and Pictures by Date

Return to Home Page

© Marty Feehan 2015