Tsunami Build Project Starts To Take Shape
Posted on December 1, 2009 by aaronredbaron
In my last installment of the long term build project I introduced the Direct Connection RC Tsunami, organized my work area, and began the build. It hasn’t taken me long to nearly complete the fuselage and make some design changes to accomodate my conversion to electric power. I wanted to build the nose of my plane to accomodate the biggest electric motor I might want. I should be able to squeeze anything with up to a 42mm diameter. After doing some research, the Great Planes Rimfire .46 42-60-800 is my first choice for this application. I want this airplane to be fast, and in order to achieve that speed I need a smaller, faster turning propeller than most .40 size nitro to electric conversions use. While most people are thrilled with the performance a larger propeller produces for vertical climbs and 3D, I want speed out of the Tsunami! The Rimfire .46 outrunner motor was recommended for its relatively high kV (800) which puts it in a higher RPM range for a smaller prop; I can use a 10 or 11 inch prop with an aggressive 7 inches of pitch on a 5s or6s LiPo battery, and I should get the performance I am craving.
The 42mm diameter can on the Rimfire will fit perfectly with my design changes; I replaced the firewall with a balsa bulkhead, and built a new plywood firewall for the nose. With triangle stock supporting it, the new forward firewall is a simple, lightweight, easy way to mount the motor, and the hatch I am adding will provide easy access as well. With the motor mounted to the firewall, the 5mm motor shaft will protrude through for the prop adapter. Any 2 1/4 inch spinner should match the nose, and I can easily fit a 6s 5000 mAh battery. There should even ample room left to shift the battery for CG adjustments.
With the fuse sides already completed, it was easy enough to mount the bulkheads. Next came sheeting and lots of sanding on the nose. The stock bulkheads for the turtle deck were light ply. I kept the last one, and replaced the rest with 1/16th balsa, with the front one being two ply, crossed grained balsa. With a little light sanding of the bulkheads, I was able to get get everything to line up fairly nicely for the sheeting. Soaking the Balsa in hot water first allowed me to wrap the sheeting easier, and then I allowed it to dry before I added the top stringer and sanded it all smooth.
I have already determined where the hatch is going to be cut, but I have to finish framing the canopy area and consider how I am going to implement a latch before I cut the hatch free.
