Cable Splices

Got a good start on making cables today.  All the splices are the wrapped and soldered style.  Started out making a couple of practice ones first.  As I mentioned in a previous post, they don't conform to any standards I've seen, but decided to make them like the original ones anyway - that was how the airplane was type-certificated.  I was a little concerned how easy they would be to make.  2 strands of wire are looped through the thimble, then all 4 ends wrapped around the cable simultaneously.  I wasn't sure how easy it would be to keep all 4 strands tight and nested without criss-crossing them, but it actually turned out to be  easier than what it may seem.

The elevator cables are made from 1/8" 1X19 and the rest from 1/8" 7X19.  This is a drawing to show how they were made.

Here's a sequence of pictures and a description of the process.

 This is what you'll need:

• A fixture to hold the cable and thimble (easy to make if you don't have one)
• Cable cutter
• Heavy-duty soldering iron
• .035" galvanized wire to wrap the cable
• Non-acid liquid soldering flux
• 1/8", 50/50 solder

 The cable I used had a lot of grease in it from the manufacturing process that "cooked" out when heated with the soldering iron.  I made this tube that is filled with lacquer thinner to clean the ends.  Worked good, although it looks like a stick of TNT!

 To begin, the cable and thimble is put into the fixture.  I used the vise grip with rubber tubing over the jaws to pinch the cable tightly to the thimble as I started wrapping.

Note:  typically, the little tangs on the end of the thimble are bent up prior to wrapping.  The original cables did not have these tangs bent up, which is how I made them.

This is how the wrapping starts.  2 strands looped thru the thimble, then all 4 strands laying side-by-side and wrapped tightly around the 2 cables. 

Sorry for the picture being out of focus...

 Wrapping continues up to the first inspection gap - a gap in the wrapping about 1/8" wide that allows the cable to be visually inspected for slipping.  These cables have 2 inspection gaps about 1 3/4" apart.

 Here you can see the wrap is nearly complete with 2 inspection gaps.  In this photo I'm trimming the end at an angle to allow the wrap to gradually taper down.  It worked easier to make this cut now than at the beginning - I could make sure the length was right, and that the taper was in the correct direction.  I used a cut-off wheel, but notice I put in a piece of scrap steel to keep from nicking the good side of the cable.

 Here it is, ready to be soldered which is actually the easiest part.  You'll need a big, heavy-duty soldering iron.  I believe mine is 150 watts, which is about perfect.  I work from inspection gap to inspection gap.  Start by brushing on the flux, heat the area, and apply the solder.  The solder flows nicely once everything gets heated up.  It will look kind of nasty at first, some of the oils from the cable will still leach out.  Just take a cloth and wipe it while it is still hot, and it will make it all bright and shiny.  I highly recommend using nothing more than a soldering iron, i.e. no torch.  You don't want to heat the cable up to the point that it will weaken it.

Once completed, scrub it with soap and water to clean off any remaining flux.






Voila!  Here's a finished one (top) with an original on the bottom.

I had to make 4 elevator cables.  Lincoln-Page doubled them up: 2 on the top of the bell crank and 2 on the bottom.  Still need to make the rudder cables (2 that go back to the rudder, and a couple of balance cables) then the ones for the ailerons (3, one to each lower aileron and a long balance cable in the upper wing).

More to come....