Cook 45 Riser

Then one day I was sent a package of plans by a friend, Gray, and one of the plans was the Cook 45 Riser. I sat down and read the original article, studied the plan, and the next week went to the Watford Swapmeet to buy a couple of silenced Cox 049s.

The Riser is based on an old 1930's rubber powered twin pusher, or A frame. Rubber motors were, in those days, the only form of power available to the masses. Any member who has visited Middle Wallop, England, during the Easter or August Bank Holiday free flight meetings, might have caught a glimpse of these amazing machines flying.

Construction was not difficult, and the two-channel radio installation just as easy, but trouble came when trying to start the engines. Cox engines run on a 20% castor fuel, and when they are left unused the castor dries into an increasingly hard varnish-like glue. The engines I had installed were old and unused, but I had cleaned them as best I could. However, the real problem was the size of the tanks. A standard Babe Bee 049 gives about three and a half minutes of engine run, and by the time you have started the second engine, launched the model, and climbed away to start flying the first engine has run out of fuel.

So back to the drawing board and the acquisition of a pair of Cox QZ engines. These are basically silenced Cox Babe Bee engines with larger tanks. This gives me time to start the engines and walk to the launch point, rather than having to gallop!

One further complication was that I wanted to make the engines run in opposite directions, as this would stop any unwanted torque problems from the twin-pushing configuration. Cox engines will run happily anyway, so having bought a matching 6x3 pusher and tractor propeller ages ago I installed them. Starting the engines has, therefore, an added twist, in that I have to swap the 12 volt terminals of the little starter I use, after I start the first engine. So long as I get this the right way around, all is usually well!

Flying the Riser is easy, so long as I remember that the engines are not controllable in the air, and the fact that the model it is going backwards! I have had many flights since finally sorting the engines, and hope to have many more.

The original engines	The beast in flight*