Chapter 16 - Section 5

Routing and Rigging Rudder Cables

 

Making the Electrical Conduits

I followed the plan and cut up strips of urethane foam from leftovers in Chapter 13. I ended up with six 22" strips of foam. With 3 per, I ended up with two 66" forms. I first laid down a wide strip of packing tape on my work table. Using a strip of double sided tape and a straight edge, I stuck the foam strips down temporarily. Then I applied duct tape over the foam strips and secured them in place.

 

I only laid down 1 BID layer over them because I was concerned that it may not want to conform to the fuselage sides later on. I also peel plied over the entire strip to cure. Once the glass cured, I popped the electrical conduit off the mold and trimmed to length.

 

 

 

Attaching the Electrical Conduit to the Fuselage

My concern (regarding the conduit conforming to the fuselage curvature) was correct. I had to push the conduit down somewhat hard so that it conforms to the fuselage curvature, especially the front portion of the conduit. I decided to take the main wheels off and lay the fuselage sideways such that I can weigh it down during the attachment process. Instead of floxing the conduit in place (per plan), I used 5 minute epoxy on the entire length of the conduit to hold it in place temporarily. Once cured, I glassed in a 1" BID tape along the conduit flange and the fuselage - full length, both sides. I also peel plied for a smooth transition.     

 

Rudder Cable Conduit

I tacked down the rudder cable conduit along the top of the electrical conduit, every 6", with hot glue. Then I glassed the nylon conduit in place in between the hot glue spots. However, I made sure that the glass BIDs are always at the front and ends of the conduits because I expect the maximum pulls and tugs will be at these locations.

 

 

 

 

 

 

 

 

Notch at the Instrument Panel

The plan calls for extending the rudder conduit through the pre-cut notch at the instrument panel (Chapter 4). Since I am using the hanging rudder pedals and  my rudder legs are a bit higher (from the fuselage floor) than the lay down rudder pedals, passing the rudder conduit through this notch will cause a slight dip in the flow of the conduit. If you look close, you can see the relative position of the pre-cut notch about 1/2" lower.

 

I used a laser and marked a straight line from the top of the ELECTRICAL  conduit to the center of the rudder pedal attachment point. I drilled a new hole through the instrument panel where the laser beam crosses it. This gave me a smoother conduit flow. I was aware that the lower tip of the control stick fork will hit the conduit - ONLY if I have to rotate the control stick to +/-40 degrees. Since my control sticks are limited to +/-25 degrees (ref. previous section), I should be OK.

 

Adjustable Pedal Travel & quick disconnects

The plan suggested a simple cable connection that can be added in line with the rudder cable such that it can accommodate pilots of different heights. I am more concern with any slag in the rudder cables - but that can be better served with a turnbuckle. I went ahead and made the parts since they are rather simple to make. I will decide if I'll use it or not when time comes.

 

Here's a picture showing the basic idea of how I plan to hook the rudder cable to my rudder pedal. I have to fabricate a button holder for good fits of course.