Making a foam wing for radio-controlled aircraft uses a straightforward tooling technique that quickly creates a durable design. Choosing to make a wing from foam rather than from wood decreases the work time for the project and creates a wing that is less likely to break. It is also more cost effective to make your own wing rather than to buy one prefabricated. You use cured polystyrene blocks or billets available at drywall retailers, hardware and model stores that come in many sizes to make the foam wing.
Choose a design for the foam wing and draw a full scale outline on paper. Draw the top and bottom of the wing. Cut out the paper patterns using scissors.
Position the wing patterns on top of a piece of birch plywood. Draw around the patterns onto the wood. Cut out the wooden template using an electric jigsaw.
Use 400-grit sandpaper to sand the edges of the plywood templates. Run your finger along the edges to feel for any roughness. Use increasing sandpaper grits to resand until the edges are smooth.
Choose white polystyrene foam when the wing weight is an issue, such as for large span wings. Choose the heavier, blue polystyrene when high strength is critical to performance, such as in RC racing planes.
Cut the polystyrene foam to the wing depth you require using a hot wire modelling tool. Push the wire gently through the polystyrene to remove excess foam from the length. Cut the foam to the length of the wing template to create a rectangular wing shape.
Center the top plywood wing template on top of the foam rectangle. Position your hand in the middle of the wood template to hold the polystyrene. Position the hot wire against the plywood edge and perpendicular to the foam. Move the hot wire along the template edge, cutting through the foam to the match the shape of the wing template.
Turn the polystyrene over and place the bottom wing template on top of the foam. Repeat the cutting procedure to shape the wing bottom. Use the hot wire to cut out wiring conduits in the foam wing according to the radio-controlled aeroplane design requirements.
Apply epoxy glue to the foam wing and allow the glue to become tacky. Cover the foam wing with a skin to complete the construction procedure. Use thin balsa wood or brown parcel paper dependent upon the type of wing strength you need for your RC model plane.