Flying Models Centerfold Plan - December 2010
When time to spare is at a premium, this all-sheet freeflight design beats the clock. Builds up super fast with minimal tools, and stays aloft super long
By by John R. Walker
The title doesn't mean the model flew that long. That's how long it took to design and construct the first model and get it into the air—and almost on the house roof.
Our grandson Matthew was visiting us and wanted help in putting together a model he had brought along, plus he found one packed away in a cabinet we were cleaning out--both plastic. After assembling them and watching them sit there and do nothing, Matt thought it was time to build a "real" model. It didn't take long to gather a sheet of 1/16 x 2 x 36 inch sheet balsa, a section of 1/8 x 1/2 x 12-inch strip and the other odds and ends that a simple all-balsa model would require.
Since the model we talked about didn't sound half bad, we decided we should make cardboard templates of the various parts just in case it flew well enough to make several more (and help him cut out the parts more easily). Using sharp cutting tools, and with the templates as guides, the various parts were cut to shape. After sanding the edges round (except where there was a glue joint), the model was assembled.
We used medium viscosity cyanoacrylate throughout. However, instructions were given on how to use the adhesive safely. Testor's Cement for Wood Models may be used instead. However, it just takes longer to dry. Use either adhesive in a well-ventilated room. We made sure the parts were joined square and the correct dihedral was put in the wing panels.
The wing mount must be a snug fit with the fuselage. When the model has been trimmed out, the wing can be glued in place. Be sure the mount is down solidly on the fuselage before making glide tests, and check its position after each test flight. A loop of 3/16 SIG rubber was used as power. The loop was just long enough to fit between the prop and tail hook. A longer loop was used after the model was trimmed out.
Adjustments were made until we got a nice glide. Move the wing back a bit if the model stalls, and move it forward if it dives. A hundred winds were put on the rubber motor and the model was launched. I think Matt was as happy as a 12-year-old can get. Then we started to look into variations. First we tried a wing with polyhedral. Great flights. We also ended up building a 15-inch span Pursuit and a 13-inch span Racer. The Racer and Pursuit used a 5-inch propeller.
Now came the decorations. Since the model is best flown in the evening, a thin coat of SIG Lite Cote was given the wood. This protected it from moisture that forms on the grass on some evenings. Felt tip pens can be used as color. Stripes can be made from Japanese tissue or Chart Pak color graphics art film.
We didn't have time to experiment with swept back or swept forward wings, tip winglets, "V" tail, etc. These can also be made an ROG (Rise Off Ground) by adding an 0.025" music wire landing gear with 3/4" plastic wheels. The model is ideal as a Scout project or as a production problem in the school industrial arts shop.
This plan originally appeared in the March 2009 issue of Flying Models.