About the Plane:

The RV-8 is a popular homebuilt aircraft. It is made from mostly aluminum and flies over 200 mph on a 160 hp engine. The model follows the form of the full size plane. It can be made with and without ailerons. The construction is just like a big rubber band powered model. Just simple sticks and sheeting. With a geared motor the plane flies great.

Flying the Model:

7/16/03: The RV-8 continues to fly with the 8.4V (7-cell) pack. A change from the stock Kyosho 9" propeller to an APC 11x7 Electric Prop made the difference. The 11x7 is a good match to the geared 540 can motor. The plane climbs solidly and flies at a good speed with ample control response. The model is aerobatic as is the real plane.

5/16/03: It really flies!!! Yeah! I added a cell to the battery making it a 8.4V pack. The plane accelerated and pulled itself into the air without too much effort. A too aft CG made the flight a little exciting. The plane looked good in the air and had good responsiveness to the control surfaces. Having said that, one more cell is required to make it the plane I want. Over the course of the next week, I will add another cell, bringing the pack to 8-cells or 9.6V and 1500 mAh. I think this will be a good compromise for power vs. weight.

The full-size plans will show my battery mounting scheme. Because of the long nose moment, the radio was installed in the aft portion of the cockpit area to balance out the motor and gear reduction system. The battery is mounted close to the CG in the fuselage above the wing.

5/13/03: It flies! Kind of.... I have test flown the plane and it is very stable. Very stall resistant!. It had to be. I installed a 6-cell 1500mAh battery for the test flights and the plane is under-powered. I could fly it close to the ground in almost full stall without and bad tendencies. The wings remained level, and the rudder and elevator were very effective. The large amount of dihedral paid off in very forgiving flight.

So this is good news for the design. Being this is my first electric airplane I am very happy with it. It will make for a great after-dinner flyer.

I always planned to use a 7 or 8 cell battery and the plane needs it. More to follow when I get more voltage. I plan on adding one cell the pack, for a total of 8.4V. Once that is done I will give an update on the performance. I will keep adding cells until I am happy with the performance. Based on what happened, 8 cells might be the right quantity.

Construction Highlights:

7/16/03: Construction is very basic. If you have built a rubber band airplane you can do this. The fuselage sides are made from 3/16" square balsa. The left and right fuselage sides are made right over the plans. Use wax paper to keep the glue from sticking to the plans. The two halves are glued together at the rear most point, and the 3/16" square sticks are added top and bottom. Build the plane upside down on the plan to keep it straight. Install the wing and landing gear mount, and remove the plane from the building surface. Add the firewall and upper and lower formers and stringers. Add the top and bottom sheeting. Add the nose block and carve/sand it to shape.

The tail surfaces are built directly over the plans. Use 3/16 square balsa, and 3/16" balsa sheet as shown.

The wing halves are built over the plan as well. Use either spruce spars, or balsa spars with 0.007" carbon fiber cap strips. After the halves are completed, glue the two halves together with the desired dihedral. Wrap the center of the wing with 1" wide fiberglass cloth strip and thick CA

The fin and stabilizer are glued to the fuselage. Make sure they are straight with the centerline of the fuselage, and 90 degrees to each other.

Cover the plane with plastic film. Add the canopy after the fuselage top has been covered. I found a hot glue gun works very well for attaching canopies to fuselages. The glue is even 65% nitro fuel proof! Add radio, control linkages, speed control, battery, and motor. Temporarily add the wing and adjust the battery location until the plane balances at 25% of chord.

3/4/03:

Due to popular demand, the drawing now includes ailerons and the use of nylon bolts to hold the wing on!

The speed control has arrived and I am getting ready to install the radio. I am running a little behind schedule, and the weather has been miserable for flying. I will fly the non-aileron version. If it flies like I expect, the aileron version will only fly BETTER.

1/12/03 Update:

The basic airframe is finally complete :-) As you can see, this is a well proportioned model, with a wide-chord, thick-section airfoil, a large open fuselage, and big, scale control surfaces. I decided not to install the wheel pants and landing gear fairing. I wanted to keep the plane as light as possible. Covering is a variety of black, yellow, red and orange plastic films. The forward potion of the cowl, and landing gear were painted with spray enamel paint (not fuel proof, but who cares!) Lettering was cut from white plastic film. Canopy was cut from a large 20" Sig bubble canopy. It is not scale, the real one would be much larger!! I don't have the ability to form canopies so the Sig had to do. The plans show the profile of the real canopy. This model is approximately 1/6 scale, A pilot would be very big and heavy. For this reason I did not install a pilot.

Radio has not been installed. The plane will use Rudder, Elevator, and Throttle through the speed control. The scale wing dihedral was increased to account for the lack of ailerons.

12/31/02 Update:

The tail surfaces are now being covered. Look for the completion of the model in 2003…

Construction is nearing the end. The basic airframe is complete. After some thought, I have added reinforcement to the wing by adding 0.007” thick carbon fiber caps to the main spar and shear webs out to the wing tips. This has really stiffened up the wing. The plans call out 1/4 square balsa spars. If you use balsa, you will need the carbon fiber cap strips. Spruce spars do not need the carbon fiber, but are heavier. The model will be powered by a Kyosho 540 can motor with a 2.25:1 gear reduction, turning a Kyosho 9” propeller. I plan on using a 30A speed control and a 7-8 cell 1200mAh pack.

Here is a view of the bare airframe: