Bulli (oz15449)

About this Plan

Bulli. Radio control sport biplane model. Wingspan 1100 mm, for 2.5 to 3.5 cc engines.

Quote (google-translated): "Construction instructions: RC Modell Bulli. The idea behind the design was to create a model with a sufficiently large supporting surface and, on the other hand, to keep the components as small as possible. This would make it easier to transport the model. As it was designed with removable undercarriage and tail unit, this was actually achieved. But the biplane's well-known good-natured flight characteristics and its safe cornering behavior also played a role in the design. In conjunction with the planned control of the ailerons via two radio channels, Bulli flies completely uncritically and is ideal for the first remote control attempts. The realistic flight pattern will also always be attractive for experts.

The slightly increased construction effort due to the second surface is fully justified by the advantages mentioned. Bulli is designed for use with model engines with a displacement of 2.5 cc. If it is intended to fly in strong winds, a more powerful engine is recommended. With a displacement of 3.5 cc, the model flies quickly and can cope with all requirements.

Basically, two radio channels are sufficient for remote control of the model. However, the use of an engine throttle with another two channels has a number of advantages.

With the aileron control, ground takeoff on concrete runways is possible without restriction. Hand-launching a biplane of this flight mass requires practice and an experienced starter. If there is no runway available and the model is to be started by hand, must, you should consider whether it would be better to do without the wing and limit yourself to the high-wing model. In this case, you would only have to close the cutout for the lower wing and attach the main landing gear there. If the upper wing is enlarged by two rib spacings, a fully-fledged RC model is created.

Finally, the Bulli can also be flown as a sports model if there is no remote control system yet. Since the flight mass is significantly reduced, an engine with a displacement of 1.5 to 2 cc is certainly sufficient. When used as a sports model, it is necessary to reduce the tank so much that only short flight times are possible.

The structure of the fuselage: All essential individual parts are numbered according to the sequence of work during assembly. For the hull sides 1 and the hull reinforcements 2, the choice should not be too heavy, a medium-hard quality is sufficient. This specification applies to almost all individual parts of the model. The few exceptions are pointed out..."

Direct submission to Outerzone.

Quote: "Another GDR model: the bipe Bulli by Lothar Hennicke from Leipzig. Probably designed in 1969 or 1970, there was also a float kit available. The font 'Impuls BT' for a decal can be found here: https://www.wfonts.com/search?kwd=Impuls

Supplementary file notes

Instructions.
Parts list.

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