AS W20 1/3 Scale w/Hacker Electric Motor
This project started about 10 years ago with the acquisition of the 1/3 scale fuselage. The fuselage was made from a mold originally built by Mark Smith. The mold has been passed to many homes and now resides with Niagra Models.
A chance visit to another modeler who had acquired a fuse and had purchased a set of wings and a stab from Ed Whyte (Whyte wings). Bren Lugo was instrumental in the fabracation of the wings and has a set on his AS W20 that is complete and flyable (the only other one I know of). The short of it is that the parts were loaded into my car and transported to my storage area where they languished for a couple of years.
So along comes Jim Lauderman who is a scale model affecionado. He has several including a couple that are electric powered. Somehow an agreement was made that Jim would do the wood working, covering, painting and detailing and I would provide the electrical and mechanical equipment. About two years later, in June 2006, the model was winch launched for the first time, the motor started and the big glider took to the sky. It proved to be remarkably easy to fly, has good L/D, flys at a realistic scale speed and has enough power to climb to thermal altitude. It is not unusual to achieve an hour long flight with only one or two motor runs.
Below are some pictures of the AS W20 in flight and some of the details of construction.
AS W20 in flight at Poway, California
Ready to winch launch. Note bridle attached to under wing tow hooks
Cockpit area looking aft. Dual green, 1100 Mah batteries power the flight control system. The white power batteries are 2 IB 4200 14 cell packs. Combined with the motor and controller they provide the correct CG location along with good power and duration. Someday we will clean up the cockpit area, add a floor and more detail.
Note folded propeller (invisible in flight). Motor is a Hacker B20 8L turning a 12 x 10 Graupner folding propeller. The system produces about 1700 watts for a power loading of 85 watts per pound. Model climbs at about a 40 degree angle at an estimated 500 ft per minute. Flaps aid in all flight regimes.
Outer wing panel joiner system showing .500 inch aluminum rod joiners. Both carbon fiber tubes extend through the inner panel and into the outer panel as far as wing thickness permits. The aluminum joiners are strong enough for the loads encountered and give realistic wing flex when the model encounters a gust.
Inner wing panel atachment to fuse. Note that joiner rod hole in fuse is larger than rod. The fuse load is carried by the fore and aft alignment pins (1/8 inch steel).
Note location of under wing tow hooks. This location gives very little rotation on launch giving a very well winch tow.
Rudder post showing reenforcements and hinges. Rudder is removable for transportation. Fuse just fits diagonally in the 8.5 foot truck bed.
Additional information is available from me (Don Richmond) at hilaunch@aol.com. The spar tubes and aluminun joiners are available from www.hilaunch.com. I do not make wings, but there are persons that do. They can be found through the internet with a querry through RCSE or RCmodels.