4C-Baby
After some weeks of test flights with the reproduced Heli-Baby now I began to think about a four cycle motor in this nice machine. Fan and clutch were originally leaned from the big Huey Cobra, are so in each case not undersized. During forward flight the necessary power is sinking very much, aerobatics are not possible, and during final landing a high-torque-motor is recommended to have a good control at this moment. These are good circumstances to try a valve engine, if....the head-mounted valve drive is fitting between the frame. But this is not possible in the original frame, so I had to design a new frame. On the Nurnberg toy fair I saw a cut-model of the Saito FA56 and conclused to try this engine. The motor is designed and produced excellent and I ordered at once on the fair one sample in the GK version ("Golden Knight") with black housing and golden valve caps. The running in of the motor I did on a fixed test unit with a 12x6 prop. After two 15oz. tank fills with CP5% with frequently changing speeds (first fill not over 5000 rpm) the motor was fully run in and working under high load as well as in lowest speed without any additional glow. The acceleration from low idle was as good as the regulation during the whole range. I am curious now about the results in the 4C-Baby. Because the motor is really nice I concluesed to turn it 180degree to show it better. For a better CG I had to move the motor before the main gear wheel and also the tank must be positioned lower because the carburetor is at the end of the motor. Of course this construction is quite far away from the original now, but I had to choose the best configuration for this expert version of the Heli-Baby. and this is particulary different from a two cycle version. Parallel I will also test the new OS FS 56, which is also now for my tests in stock.
