Stingray Installation Instructions
Below are some photographs of the stingray installation as supplied by Bob Price.
Improved dive-brake control arm.
Looking down through the dive-brake opening.
Looking through the cockpit opening.
Tank supports seen through the main landing gear doors.
The following suggestions on how to mount the Stingray tanks are based on what I believe is the need to hold the tanks in the fuselage firmly and not to apply fuel weight pressure to the bottom of the fuse. The tanks are put in the fuselage on at a time down through the canopy opening. Place one tank in and slide it back and then place the other tank in and slide it back along the other. They are shaped to fit the fuselage cavity with little clearance to get the maximum fuel capacity.
The front of the tank is held up to the plywood speed brake servo plate using screws that screw down through the top of the servo mount surface between the servo and the end of the canopy opening into wood blocks (3/8” x ¾” x 2”) which are glued to the front face of the tank 1/8” down from the top surface of the tank. The 3/8” thick block just fits between the servo and the tank front surface. Make sure to sand the tank surface where glue is applied. I used Aeropoxy here.
I used spruce for the wood blocks (execpt where ply designated) but other hardwood or basswood could be used here. I have a supply of Sitka spruce left over from old spars from my full size Aeronca Champ.
Glue a 1/8” x 1.5” x 10” strip of plywood on the back surface of the rear bulkhead which is just in front of the wheel wells. A small amount (only about 1/8”) of the end (arc shape) of each bulkhead is cut away before the ply strip is glued to the bulkhead so that the end of the tanks fit through the bulkhead opening to the back surface of the bulkheads. Make sure both tanks fit through the rear bulkhead opening to the back surface. The ply strip is positioned to the bottom of the fuse.
After the ply strip is glued in, slide the tanks in and mark on the tanks where the top edge of the ply strip with a short cut off pencil so that the pencil will fit inside and the line is drawn exactly where the top of the ply strip is located.
Glue a ½” x ¾” x 2” wood block to the back surface of each tank at and above the pencil line. Again sand first.
Glue a ¼”x ½” x 4.5” ply block to the back surface of the ply strip with the ¼” edge glued to the ply strip (ply block lays horizontal). The top of the ply block is flush with the top of the ply strip. The tank is held down to the ply strip using wood screws through the bottom of the ¼” ply block up into the wood blocks glued to the tanks.
I have also modified the speed brake control horn setup on my plane. I don't like the stock control rod setup because when the speed brake is up full (needing the most servo power) there is a very large angle between the plane of the servo arm and the linkage to the speed brake. This is a very poor way to get the power needed for the speed brake delivered from the servo to the speed brake.
I have ground the control post boss and supplied round plywood post support in the center between the vertical hinge members and glued in a plywood plate. I made a control horn out of aluminum angle material and screwed it down to the new plywood platform. The control linkage point is now farther forward and at a much better position relative to the hinge pin. There is now a straight line between the plane of the servo arm and the control linkage hole on the control horn allowing full power to be transmitted from the servo to the speed brake.
Feel free to call me if you have any questions about this tank or speed brake installation. Bob Price, 512-259-9232.
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