Tsunami Build Project Gets Special Access
Posted on December 18, 2009 by aaronredbaron
One of the major design considerations with the conversion to electric power is how to access the batteries. Although the model could be kept simple with access to the battery requiring removal of the wing, I chose to modify the Tsunami with a large access hatch to the top of the model. The new hatch incorporates the entire canopy area, and far enough forward to facilitate access to the motor. With the hatch freed, the fuselage needed some reinforcement to provide adequate strength. Stringers and cross members were added from behind the hatch all the way to the firewall.
Before the additions, with the hatch removed, the fuselage did not offer adequate torsional strength, and the fuselage sides were easily flexed. With the addition of stringers the flexing was reduced, and cross members were added with consideration for how the battery would fit between them. The fuselage still needed additional strength; I decided and the best way to further strenthen the fuselage was to support it with the hatch itself. With light-ply tabs spaced properly to slip into the fuselage, they will provide a method to screw the hatch down while also acting like a cross member, and still having room for the battery.
Dave Brown Products fiberglass pushrods (click here to see their website) were chosen instead of the recommended dowel pushrod. Servo selection for the tail was based largely on what was available in in the draw next to my building table; a JR 3400G is being used for the rudder, and a Mutiplex micro digi for the elevator. Both servos are metal geared and although they are smaller than a standard sized servo, both actually have more torque than a standard servo. Instead of mounting the servos above the wing as shown on the plans, I moved them just behind the wing, and added another hatch to the bottom of the fuse. With the pushrods and servo mounts possitioned aft, the nearly complete fuselage is left empty and uncluttered for the battery, receiver, speed controller and motor. At this point I have not decided whether to run a BEC or on-board receiver battery, but the model will have plenty of room for whatever I choose to go with.
