Q-101: Quite often, and at a critical time, I seem to run out of the
necessary hardware that allows me to connect control rods from my servos to the
horns located on the control surfaces. Do you have any suggestions for how I
might make these connections without the need for any special hardware?
A-101: I gather our reader friend has run out of EZ connectors and control
horns on a Sunday night, when all the local hobby shops are closed. I happen to
like using the popular DuBRO EZ connectors on my servo output arms and I certain
use a variety of clevises and control horns at the control surface end.
Recently I noted a simple approach used by my flying partner, Tom Hunt. I think it safe to say the scheme is more intended for smaller models, but it is still an interesting concept. What Tom does is take two pieces of wire—let's say .025- or .032-inch diameter. Both wire lengths are equal to the distance between the servo arm and control horn, plus an inch or two more to allow for an overlap of the pieces. Next Tom makes a Z-bend on the end of each wire. I like to make my z-bends just with a set of pliers. This is a three step process as you will note in the photos.
The alternative is to purchase a z-bending device such as the Graupner Z-Bend Pliers (GR5732) from Hobby Lobby (www.hobby-lobby.com/tools.htm). Install the Z-bend ends to a hole in the servo output arm and also a hole in your control horn. Slide a short length (approx. 1 ˝ inches) of heat shrink tubing over the overlapped pieces of wire. Adjust the control surface for the desired position and then apply heat to shrink up the tubing.
You should select a tubing diameter that is almost a snug fit with just the two wires. Then when you shrink the tubing it will really grip the two wires. When I have everything set, I usually apply a drop of five-minute epoxy cement on the protruding wire ends, just to make sure nothing slips. This process works well and is easy. But again, I would restrict its use to small model aircraft. Certainly this would not be the recommended technique for a 1/4-scale model.