Aileron and Flap Rigging

Time: 8 Hours

This weekends task was to finish up the fuel connection lines from the fuselage to the wing tanks and rig both the ailerons and flaps. The fuel lines consist of a connection for the vent line and a connection for the fuel feed. Since I had used flop tubes, for inverted flight, I had a little bit different fuel feed line vs the standard pick ups. The lines have to travel through the hole that was drilled in the tank attach brackets. They will also have a union in the line where the standard ones don’t. The vent lines just have to clear the brackets staying below the skin level so they will be hidden under the flashing that will get put there. I made the lines and their connections minus the end that goes on the fuel line that comes out of the fuselage. That will get cut and flared after the wings are removed to make room.  

   Once I had the fuel lines done I moved on to the big task of rigging the ailerons and flaps. First up is to attach the ailerons to the wings and set the neutral point. I used a digital level which has a magnet and stuck it to my control stick to get perfect neutral stick. 

 With the stick in neutral I adjusted both of the ailerons so that they were in their neutral position. This is done by aligning three tooling holes in the outboard rib and the aileron tip. When all three line up the aileron is in neutral position.  

  Once I had both ailerons on and adjusted to be in the neutral position I had to make adjustments back at the control stick to return it to the neutral position. This is done by adjusting the rod ends on the two pushrods the connect to the control stick.  Once the ailerons have been adjusted you can move on to the flaps to line them up.  Before doing this I put in the aileron judgment tool the Vans gives you to hold neutral position. This is a jig that has a hole in it for the aileron rod bolt to go through and a flat surface to sit against the wing spar. When installed the bell crank is in its neutral position but also holds the ailerons from moving.  With the jig in place I know that ailerons will not move and I can adjust the flaps to match them. The flaps need to line up with the ailerons so that as you look down the wing in neutral position the ailerons and flaps trailing edge is lined up in a perfect line. To do this with the flaps you just adjust the pushrod either up or down to get the flaps to line up with the ailerons. Before you can do this you need to enlarge the hole in which the pushrod it goes up-and-down through.  
   You need to open this whole up as when the pushrod goes up-and-down it’s geometry changes moving the pushrod forward and aft as it moves. Once you have this whole opened in the pushrod no longer hits the skin you just adjust its length to align the flaps trailing edge with the ailerons in there up position.  
 With the flaps adjusted both left and right I removed the aileron jig to check their travel in the up and down position and compare to the degrees that vans specifies.   
 All the measurements were dead on and perfect!  One thing I did find with my flaps was that I did not bend the rears are flange enough when I built the wings. This caused the wings skin to curl up just a little at the aft end of the top skin. Vans knows that this is an issue for builders and describes how to correct this with a 2 x 4 jig. I took a 2 x 4 and cut a slot in it and drilled out the center in order to bend the flange without bending the skin as I do that. 

 The idea is that the slot would allow the 2 x 4 to slide over the skin at the very tip I opened up the slot a little to slide over the rivet heads on the rear spar flange then I could use the 2 x 4 to slowly bend the flange down in turn lowering the skin. 

   This worked out well and I will do a little more tweaking on it to get it perfect. What is fun is that I can make the flaps go up and down using a 9 V battery with it’s flat motor. Kind of fun to see things working like they should!

Print Friendly, PDF & Email

Leave a Reply

Your email address will not be published. Required fields are marked *