This catapult uses a slingshot rubber band to accelerate a cart on which a glider is set. The cart is assembled from 3D prints. Wood stock is used to build the rail system and mount the slingshot band.
STL files in the catapult.zip (below) are assembled to make the cart and bracket to attach the slingshot rubber band. This cart is designed for a glider or aircraft of about 9 inch width.
The wood stock pieces for the rail assembly are of the following where dimensions are in inches: a) rail 2X 36”x2”x0.75”, b) rail sides 2X 36”x1”x0.5”, c) back piece 10.5”x3”x0.5”, d) cross 39”X1.5”X1.5”, e) cross vertical extensions 2X 12.5”X3.5”X1.5”, and f) spacer between rail and rail 2X 6”X2.5”1.5”. Screws are used for all fasteners.