Stumpy (oz14667)

About this Plan

Stumpy. Control line combat trainer model. For .099 Cub or similar engine.

Direct submission to Outerzone.

Update 16/7/2023: Added article, thanks to Pit.

Quote: "What, you haven't tried combat? Give it a go with this simple, all-balsa flip-flopper for .09 engines. Good trainer or fun ship. Stumpy, by J Richards.

With the growing popularity of combat events at contests, the need arises for a simple combat trainer to utilize engines in the .09 to .15 range. Stumpy was designed for less experienced model builders, who definitely seem to prefer the smaller engines. However, the experts also should enjoy this quick-building little stunter.

The original Stumpy proved surprisingly fast with an .099 Cub. Light weight and a slim wing section contribute to speed while giving sufficient, lifting area for maneuvers. The all-balsa construction is rugged. Construction can be completed in an evening.

Cut sides from hard 1/8 sheet. If an engine larger than .099 Cub is used, radial mounting is suggested to forestall increase of fuselage width. Cut firewall A from 1/8 plywood. Drill fuel line hole and notch for motor mounts, which are made from 1/4 x 1/2 x 5 in pine or basswood. Assemble mounts and firewall and install engine. Engine offset is op-tional. However, it is suggested that the beginner use offset or right thrust, because it will aid in holding the ship out on the lines when in high or overhead maneuvers, or when the wind tends to blow the ship into the circle.

Former B is cut from 1/8 hard balsa. Install engine-firewall unit and Former B in position between fuselage sides, cementing liberally. When dry, bring sides of body together at tail and cement well. Plank bottom of fuselage with 1/8 sheet, grain running from firewall to tail. Use similar stock to plank bottom of nose, cross-grained to take curve.

Install standard stunt tank, with feed line on outside of circle and level with needle valve jet. It is quite important to aline this feed line with the needle valve body on any stunt ship. If the tank is higher, the engine will tend to run leaner when the plane inverts..."

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