Dedicated to the Promotion of Electric Propulsion in all types of Aeromodeling

The Gallaudet Seaplane Project, Pt. 3

by Allan Flowers

The REAR FUSELAGE:

Because of the unique power system, the rear fuselage must be supported on the central tube that the propeller hub rides on. A fiberglass tube is glued into the wooden structure to engage with the aluminum tube.


A narrow hatch gives access to the rudder and elevator servos and the linkages to two jackshafts that drive pull-pull cables to the control surfaces. It also provides a place for a bolt that prevents the rear fuselage from rotating on the tube.

The propeller blades are made by cannibalizing a pair of APC two-blade propellers and cast into cubical pockets to index into the drive hub. Four were made with the best three being used.

 

A test “sled” was made to measure the thrust of the power unit. It rides on dowel rollers and has a fishing scale for measurements. The tests indicate sufficient thrust. Reliability remains to be proven.


The square section rear structure was completed with stringers to create the round shape,

 

The fin and rudder were added. The horizontal stabilizer was designed to pivot about the main spar in order to give a few degrees of adjustability.

 

Covering is Ceconite Lite with vinyl graphics from a local sign shop (from my Photoshop artwork).

 

Power is a Neumotor 1912/1Y, Castle Creations Phoenix Edge 100 and Spektrum Rx. The motor has a high KV (850) due to the belt drive gear reduction, which results in about 5700 rpm max on the prop.