Center Wing Plug Solution

Bill WingstedtPublished on February 1, 2000

I’ve done a half dozen planes now that use the computer type plug in the center panel and have devised what I think is an elegant way to support the plug so you can set the wing on the fuse, and have it plug itself in.

Why would I do this? Well, how about the wear and tear it saves on those precious solder joints which undoubtedly occurs as you fish around trying to plug the two connectors together?

The Stork offers the easiest way, since it has a well molded into the fuse for the plug. The Eclipse requires that you cut a hole in the wing saddle.

Then the problem becomes, how do you support the plug in the hole while leaving room for the wires connecting the plug to the receiver?

On the Eclipse, I cut a two-pronged, or U shaped support out of hardwood, and after several trial fits, screwed the plug to the support, plugged it into the wing, put epoxy where required on the floor of the fuse, and set the wing in place, screwed it down and waited for the epoxy to cure. When it was time, I unscrewed the wing bolts, took off the wing and voila! there was the plug, pretty as a picture, just begging to have the wing plugged into it, time and time again, no fuss, no muss. All well and good.

Now I’m working on a Sharon, and was thinking of doing the same thing. Things are a little tighter in the Sharon, though and I really didn’t want to block the only convenient access hole with a permanent installation of the plug support, because I’d like to use this same hole to install the towhook and to access the push rods. This fuse is reeeeeaaaaaalllly long and the canopy is waaaaaay up front.

So this is what I came up with.

  1. Drill a hole in a 3/16" thick hardwood block so that a 2-56 threaded rod can be screwed into it (I used oak). The block is the same length and width as the plug, including the mounting flange and the hole is located under one the holes in the flange (I originally thought I’d need 2 rods, but I didn’t, so this block could actually be smaller).
  2. This wooden block is then epoxied into the fuse, underneath where one of the holes in the plugs mounting flange will be. This is the only permanent part of the installation.
  3. You then must determine how long the threaded rod needs to be to support the plug at the proper height, on the Sharon it was about 1-3/4".
  4. Then, using a cutoff wheel, cut a notch in the end of the threaded rod, so you can use a screw driver to turn it into the hole.
  5. Run two nuts down the rod to support the plug at the proper height (I just used two to lock them in place), on the Sharon this was at about 3/8 of an inch.
  6. Slip your plug in place over the rod, put another nut on top and as you tighten it, the plug will level out in the fuse and there you have it!

The nice thing is you can adjust the height somewhat just by turning the nuts up or down the rod. Just one rod seems stiff enough for this application, and that leaves plenty of room for pushrods, wires and whatever else may be going on in there. I’ve had the plug in and out several times and now I can still put the towhook in, and more importantly, adjust the towhook more easily after I’ve test flown the plane, all through this one hole in the wing saddle.

That teensy little block epoxied to the floor of the fuse is not the least bit in my way, and all the while I can enjoy the convenience of just setting the wing on the fuse, bolting it down and flying!