KI-61 Tony

Model Airplane News, Dec 2003 by Rittinger, Mark

An electric "Rising-Sun Warrior" of the South Pacific

The KI-61 Tony was a sleek-looking WW II Japanese fighter, powered with a Japanese copy of the Daimler in-line "V" engine. Fast and maneuverable, it was a formidable weapon used against the Allies. Modelers benefit from the many different and very brightly colored (easy to see) paint schemes that are available for the Tony.

I have always liked this plane's clean, racy lines, and my simple, tried-and-true Magnetic Mayhem reverse-wind-motor setup is perfect for the Tony. The Tony is also a perfect companion for either my electric P-40 (featured in the June 2003 issue of Model Airplane News) or my P-51 (featured in the September 2002 issue), both of which are powered with the same low-cost, great-performing setup.

The construction is very simple and produces a strong, lightweight structure. The prototype was built and flown by my buddy Dave Ottney of New York, and he did a fine job; the model finished out at my target weight of 45 ounces. You can cut out your own wing-cores using a hot-wire cutter, or you could have the cores cut for you by a commercial foam cutter. Either way, the model goes together pretty quickly. There is no rudder, but if you want to add one, it isn't hard to add a movable one. Though not on the plans, retractable landing gear wouldn't be difficult to add either.

POWER REQUIREMENTS

You don't need a brushless or even a cobalt motor to power this model, but since the prices for these are really coming down now, they might be worth a try. Several options for brushless power are out there: AXI, Jeti, AstroFlight, etc., direct drive or geared. As long as you get about 250 watts out of them, you'll be OK. Any 30A ESC with BEC suitable for 10 cells will perform well. As for "fuel," you can use anything from 800AR cells to 2000 NiMH cells.

CONSTRUCTION

The fuselage. The Tony's allwood fuselage is based on a simple box structure with a rear turtle deck. Begin by cutting the sides from 3/32-inch balsa. Avoid wood that would require a seam anywhere near the rear deck-it will crack. Cut to shape and attach the doublers to the sides. Make an appropriate motor mount; I used an 1/8-inch-ply mount. Glue it to one fuselage side using triangle stock, making sure it is square to the side. There is no right thrust, but you should include 3 degrees of downthrust. Add plywood former F2 and the balsa F3 to the same side, then attach the 1/4-inch square pieces near the hatch and former F2. Add the triangle stock to the bottom edges of the fuselage side, then add the stabilizer doubler. Attach the second fuselage side and glue it to the formers and the motor mount. Pull the tail ends together and glue them together, then install F4. Make sure that the fuselage remains straight and true.

Add the 1/4-inch-square top rear longeron, and wet the outside of the deck sheeting to help bend it into place. I used medium CA to glue the sheeting into place while it was still wet. Mark the location, and cut the other side to fit. By slightly pushing outward on the deck, you get a nice, full, rounded shape.

Glue on the nose ring, then tack-glue the nose blocks on and carve them to shape; then remove them, and hollow them out with a Moto-Tool. They can be built right on the fuselage for strength or made removable for access. I glued them on for a strong unit. On the Tony, a bottom hatch would be fine. Cut a cooling hole or two in the nose (the gun ports would work well).

The radiator scoop holds up surprisingly well when built up from balsa, though a solid block can be cut and carved also.

Main hatch. The hatch is built on top of the assembled fuselage. Begin by making the cockpit floor from 1/16-inch cross-grain balsa. Use former F2 as a template, and make the front piece of the hatch from 1/8-inch balsa. Cut 1/16 inch off its top to allow for the hatch sheeting. Add all the other hatch formers and the hatch 1/16-inch balsa sheeting. Add some alignment pieces to the bottom of the hatch so it will fit straight on the fuselage. The canopy on the prototype was homemade, but you can use the front part of a Sig WW II-style canopy and use flat acetate to form the rear section. I held my hatch in place with small "rare earth" magnets from RadioShack.

Tail surfaces. The fin, horizontal stabilizer, elevator and rudder are all made out of simple 1/8-inch-sheet balsa. Use flat, strong, lightweight wood. Attach the stabilizer to the fuselage, and then use a 90-degree triangle while attaching the fin. Add light, balsa filler pieces above the stabilizer, and cut the elevator halves to fit. I used a hardwood elevator joiner, and it worked well.

THE WING

Cut the wing of pink insulation foam from a home-supply store. Use the 2-inch-thick foam. Do not use white foam for wing-cores! There is a chance that the wing might fold if you use the 1/32-inch wing sheeting shown. After the cores have been cut, sand them lightly to remove the "fuzz," then cut out the servo wells, the handhold and the grooves for your aileron servo wires. I taped the core beds to the table and then cut the 1/32-inch wing sheeting to fit. If you intend to use a brushless motor to power your model, I suggest you add some carbon-fiber strips or replace the sheeting with 1/6-inch balsa.