Combat Stooge

Here is the completed launcher or stooge from the top/back. It is based on a common folding saw-horse (available at Bunnings in Australia) and a few common hardware components. You can see that it points upwards fairly steeply, so that the model can "helicopter" a little until horizontal speed builds up to generate genuine lift from the wings.

The front view shows how some of the bolts are used to hold the wing-casing together as well as attach it to the saw-horse. There are nuts on the outside of the wing-casing as well as on the inside of the 3-ply at the leading edge. This holds the ply at the correct spacing and add rigidity. Note that these photos were taken before the bolts were trimmed to size after initial launch check verified that the spacing of the wing casings were correct for the size wings used.

Here's where we start. The main components are: the saw-horse (not shown), 3-ply 6mm thick, a thin rubber mat with a cloth or "furry" top, some 12mm square soft wood (pine in this case), and some continuous threaded rod 3/16", along with flat nuts, nyloc nuts and washers. The nyloc nuts are used on the outside of the wing-casings and the flat nuts are used on the inside of the ply at the leading edge.

This mat had "stripes" of cloth which were lined up front to back - this helps grip the wings around each rib on the model.

The wood sheeting is cut to somewhat larger than the wing dimensions will be when inserted. In this case (for F2D wings) I've used 49cm x 36cm rectangles tapered to 19cm at the tip. Its best to have the grain of the outside ply running length-wise along the wing, as it needs to be stronger in this direction. The square pine is white-glued along the trailing edge of the wing-casing halves. It's useful to seal the wood with some fuel proof paint - Estapol has been used here (1-part poly-urethane paint).

At this point, some clamps have been used to get everything fitting correctly. Fold over the rubber mat (furry side inwards) and put the plane wing into it. Fit the wooden casing halves around this and get everything aligned before clamping together (at least at the trailing edge). It worked out better to leave a little rubber matting protruding from the insertion side of the casings (so that the wing never contacts the ply edges). When the fit has been sorted out, remove the plane wing and drill the necessary holes in the ply, matting and saw-horse. Then use the continuous "bolt" to make up the right length "bolts" for each location. Fit these bolts with the wing in place, so that the correct space is made between the wing-casings at the leading edge.

When it is all bolted together, trim off the excess matting from the trailing edge, and grind off excess threaded bolt length.

This view shows the slightly protruding matting so that it is easy to push in the F2D wing without touching the wood. The finishing touches are really to spread the legs of the folding saw-horse so that it will be stable and withstand the sideways pull at launch time. The rear legs of the saw-horse can be removed since they don't do anything useful.