Monday, November 18, 2019

Control Cables

I started making my control cables today. The manual is again weak in this area. It does specifically state to measure out two eight foot pieces for the flaps. No other measurements are given for the rest of the cables. So, I measured out and cut the two eight foot cables.

Then the head scratching began. No part numbers are given, just a couple of grainy pics with instructions to hook up as shown. I started with the turnbuckles since I knew they were definitely involved and I could locate those parts. Having never worked with turnbuckles, I was immediately confused because I had multiple packages of what appeared to be the same parts with different part numbers and different quantities of each?

I started scouring the usual web sites looking for clues, pictures or even directions. I ended up looking up the part numbers on Aircraft Spruce's web site and fortunately, they had a diagram showing the relationship of some of my parts. Finally after fiddling with the parts, it dawned on me that some were reverse threaded, this made it easy to get all the parts together... they only would go together one way. However, I did have two fork ends while there were five cable eyes? I figured out that the fork ends actually hook up to the rudder pedals. So, I ended up with seven completed turnbuckles. From this two for rudder pedals, two for flaps, two for down ailerons and one for up ailerons. The manual does say to screw the eyes into the barrel until no threads are showing, this is the mid point and allows 1" to 1.5" of adjustment in either direction which will be plenty.

So, I decided to start with the rudders. First I tied a string to the rudder pedal and ran it back to the rudder adding a little adjustment, marked and measured it. Then measured out and cut two lengths of cable to match. I swagged the thimble to the cable eye on the rudder pedal end and put the turnbuckle assembly together and bolted it to the rudder pedal. The directions suggested to fix the rudder pedal in a position 18" from the "control tower" where the sticks are located. I fixed the rudder pedals in place and ran the cable through all the cable guides in the fuselage back to the rudder.
The rudder had to be centered and braced so not to move. Then I had to drill a hole in the tabs on each side of the rudder to accommodate the AN3-5 bolt for the shackle. A thimble goes on the shackle and is swagged in place with the cable being drawn tight.
Repeat for the other side.