Building a 50" Jumbo Walkalong Glider
Layout on 19.5" X 27.5" X 3mm Depron Sheet from http://www.rcfoam.com. The wingspan was scaled to the largest dimension of the Depron sheet (27.5").
The sheet is cut and layed out. Note the left wing must be turned upside down. Since the wingtips from a plan with 27.5"X2 wingspan scaling go off the Depron sheet, the two triangles of excess material will be taped on the tips to augment the elevator surface area.
Next Lines are drawn on the undersides of each wing and a slight bend is thermoformed along each line to create the airfoil. I added extra lines midpoint between dimensions J, I&J and I&H to make a smoother curvature.
Here bends are thermoformed to create the elevator surfaces. Once again, I inserted an extra set of lines mid point between the K dimensions for a smoother curvature to the elevator. Note the wingtip pieces are thermoformed at the same time as the wing. Then taped in place.
The wings are taped together on the bottom surface fore and aft and the top surface midpoint. Ballast is taped to the nose, protruding forward so less mass can be used to create the same moment (mass X distance from Center of Gravity) as a heavier mass closer to the Center of Gravity. I used two nails for a total weight of 15.6 grams. A chunk of styrofoam on the nail heads minimizes damage during crashes. The tape is placed such that the ballast can be adjusted fore and aft. The completed plane weighs 56 grams.
The completed Jumbo gilder with a Z-Surfer (12" wingspan, below) and Wind Rider for scale.
Video of Completed Jumbo in flight.
Copyright Phil Rossoni 2011