The wing is held in place with two thumb screws (above left) and a wing tube. The two-piece wing makes the EVX-48 easy to transport in even the smallest
strips for the ribs. If you use hinge points, remember to include the hinge support blocks. Taper the ailerons using the same procedure as used on the elevator. Start with a 3⁄8-inch diameter steel rod along the leading edge and a 1⁄4-inch steel rod along the trailing edge. After sanding down to the rods, flip the aileron over and replace the steel rod along the trailing edge with a 1⁄8- inch diameter steel rod. Finish sanding down to the 1⁄8-inch rod.
Finishing
You can use your favorite covering method on the EVX. However, I recommend covering the fuselage with lightweight (0.58- ounce) fiberglass cloth and Z-Poxy finishing resin, blotting as much of the resin away as you can after the cloth is applied. Too much resin will just add unnecessary weight. If you glassed the fuselage as I did, it should be painted. I used NAPA DC540 gray primer over the glass to fill the weave. It is without a doubt the easiest sanding primer I have ever used. I also used Duplicolor Acrylic Lacquer for the color coats and the clear top coat. Since I also painted the tail feathers, I covered them with Polyspan and
vehicle. Two Hitec HS 255 servos (above right) provide the muscle for the elevator and rudder and are easily accessible under the hatch.
sealed them with clear Duplicolor lacquer before installing them on the fuselage. I cov- ered the wings with UltraCote.
Power system
When I was designing the EVX, I knew I wanted some horsepower but I didn’t want to put a heavy motor in the nose. I happened to have a new BP Hobbies Cheetah A2820-6 motor in my box that was rated for 550 watts. Now 550 watts was a bit less than I wanted, but my experience with the BP mo- tors is that they can be pushed quite a bit without too much harm, so I decided to use it. On a 4S Li-Po pack, I propped it to pro- duce a little over 700 watts static and I have had no issues with the motor so far. At 200 watts per pound, there sure is enough power. I had a Castle Creations Phoenix 45 speed control and Turnigy 5-amp BEC available, so I used them, securing them both with hook and loop fastener in the compartment underneath the battery tray. I also used hook and loop fastener strips and strap to secure the battery.
Electronics My radio is a JR 9303, 2.4 GHz system
that I coupled with a Spektrum AR6200 six- channel receiver. I used Hitec HS 225 servos for the elevator and rudder and HS 85s for the ailerons. I made the elevator and rudder pushrods from 1⁄8-inch diameter carbon fiber tubes with 2–56 threaded rod ends. I at- tached the threaded rod ends to the carbon tubes with JB Weld. Using thin CA, I at- tached a 1⁄2-inch long section of 1⁄8-inch ID aluminum tube at each end of the carbon tubes to prevent the tubes from splitting. 2– 56 threaded rods were used for the aileron pushrods. Du-Bro 2–56 Safety Lock Kwik- Link Clevises were used at surface control horns and Du-Bro 2–56 ball links at the ser- vo horns.
For initial flight testing, I located the c.g. 3¼ inches behind the leading edge at the wing root. I’m still playing with the c.g. loca- tion, but my thoughts are, with the long tail moment, the c.g. range should be pretty wide. The EVX has proven it can handle the wind as I have flown it in winds approaching 25 mph without any problems. With the fly- ing season over for me this year, I’m really looking forward to the Spring so I can play more with the EVX and see how far I can re- ally push it.
Ready for its maiden flight, the EVX-48(at left) poses for pictures. Jim designed a trim scheme (above, at left) that is both easy to see and track in all aerobatic manuvers and light conditions. Cruising by (above), the EVX-48tracks straight and true.
FLYING MODELS 25
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