"Two-Line Assembly" for Control Line Leadout Wire Eyelets

 - Airplanes and Rockets

Figure 3. Two-Line Construction, "Control Line General 2017-2018"

For as long as I can remember, the instructions for assembling eyelets to control line leadout wires has been the one depicted in the image to the right. It appears to be a copy of a copy of a copy of a scanned image from a printed version of the Academy of Model Aviation (AMA) rulebook. This particular rendition comes from the "Control Line General 2017-2018" publication from the AMA (Figure 3. Two-Line Construction, on page 8). Its simple presentation is fairly easy to follow, but actually accomplishing the feat can be a little tricky when using the multistrand steel leadout wire. I am no master of the task, but have constructed many leadout eyelet ends in my six decades. A pictorial representation of the process I use is given below. This is from my electric-powered Jetco E−Shark 15 control line model. Hopefully, you will find it useful.

Two completed leadout lines with eyelets assembled - Airplanes and Rockets

Here are the two completed leadout lines with eyelets assembled, so you know where we'll be headed. Choose a starting point some distance from the wingtip which allows full motion of the bellcrank.

Pass the free end of the leadout line back through the crimp tube - Airplanes and Rockets

Step 3 - Pass the free end of the leadout line back through the crimp tube, forming a loop for the eyelet. Don't worry about the exact length at this point.

Pull the leadout line tight around the eyelet - Airplanes and Rockets

Step 5 - Pull the leadout line tight around the eyelet while adjusting the eyelet position to match the other eyelet. Don't worry about the other end for now - just get the eyelet positioned and tightened correctly.

Clip off the excess free end of the leadout line - Airplanes and Rockets

Step 7 - Finally, clip off the excess free end of the leadout line. Done!

Block the elevator at zero degrees of throw - Airplanes and Rockets

Step 1 - Here, the first eyelet is already installed. Block the elevator at zero degrees of throw and find the point on the other leadout line equal to the first eyelet.

Slide the metal crimp tube over the line - Airplanes and Rockets

Step 2 - Slide the metal crimp tube over the line.

Now pass the free end of the leadout line back again through the crimp tube - Airplanes and Rockets

Step 4 - Now pass the free end of the leadout line back again through the crimp tube. This is much easier than trying to hold the leadout line tight around the eyelet while feeding the line back through.

Use a crimping tool or rounded pliers to crimp the tube - Airplanes and Rockets

Step 6 - Hold the eyelet and crimp tube securely while pulling the free end of the leadout line back toward the eyelet until the other looped end (closest to the wing) protrudes the prescribed distance (1/8") from the other end of the crimp tube. Use a crimping tool or rounded pliers to crimp the tube tightly in two location per the AMA instructions.

 

 

Posted July 26, 2019