ULTIMATE POWER

The Desert Aircraft DA-150 is the powerplant for our 10-300. This is a match made in heaven!

DA-150 Spinning the prop of our test model is the powerful and reliable DA-150 twin-cylinder 150cc gas engine from Desert Aircraft. Built with some of the latest manufacturing techniques, the DA-150 started out as a 3D CAD drawing and was engineered using stereo laser lithography technology. Designed from the ground up to be a world-class RC model aircraft engine, it has powered many Tournament of Champion and World Masters-style aerobatic aircraft. It is ideally suited to the Hangar 9 giant Ultimate bipe and powers it with authority. SPECIFICATIONS Displacement: 9.15ci (150cc) Output: 16.5hp Weight: 7.96 lb. (3.61 kilos) Bore: 1.9291 in. (49mm) Stroke: 1.5748 in. (40mm) RPM range: 1,000 to 6,500 (8,500 max.) Fuel draw: 3.3 oz./min. at 6,000rpm Recommended props: 30x10, 30x12, 32x10, 32x12 Price: $1,495 Features: the DA-150 features three crankshaft bearings (1.7 in. spread between front bearings); a standard Walbro carb with bottom induction and a 4-petal reed valve; Desert Aircraft auto-advance electronic ignition; DA cylinders, pistons and crankshaft; a 3-piece CNC-milled, 2024-T3 aluminum-alloy crankcase; and a 2-year warranty. Desert Aircraft (100%) 722-0607; desertaircraft.com.

Engine installation
Before you hang the engine on the firewall, drill holes through the box structure and into the edges of the firewall so that it will be locked into place with 1-inch lengths of 1/8-inch dowels. Epoxy the dowels in the holes, cut off the excess length, and sand the edges flush with the box surface. Measure and mark the vertical and horizontal reference lines on the firewall, then clamp the engine to the firewall and transfer the marks for the attachment holes. Remove the engine, drill the holes in the firewall, and bolt the engine into place with four, 1-inch-long, 1/4-20 cap-head bolts and blindnuts.

Cut an opening in the bottom of the box structure, install the throttle servo and hook up the throttle linkage. Install the fuel tank and plumbing, then screw or glue the box cover into place. Screws make it easier to access the fuel tank. Next, install the engine cowl and cut out the openings for the exhaust pipes and the front edges of the mufflers. Then install the prop and spinner.

A beautiful, all-aluminum Tru-Turn spinner completes the engine package.

Final assembly

The interplane struts are prebuilt and covered. They are secured with these aluminum attachment fittings.

Glue the pilot figure into the cockpit, and roughen the inside edges of the canopy with sandpaper and glue it into place. Install the radio system and connect the servos, switch harnesses and battery packs. Check that all the components work as they are supposed to, and make sure that the control throws are correct. Here are the recommended amounts:

• Low-rate ailerons: 26 degrees up; 25 degrees down.
• High-rate ailerons: 41 degrees up; 40 degrees down.
• Low-rate elevator: 15 degrees up; 20 degrees down.
• High-rate elevator: 33 degrees up; 31 degrees down.
• Low-rate rudder: 31 degrees left and right.
• High-rate rudder: 37 degrees left and right.

The recommended center of gravity (CG) is 91/8 inches aft of the top wing's leading edge measured from the center of the wing.

The main landing gear is made of super-rugged, molded carbon fiber. It is attached to the engine-box structure just forward of the main bulkhead.

That's it! When all is said and done, all you've really done is build an ARF-but boy, what an impressive ARF it is! If you take your time and do it right the first time, you'll have the hottest aircraft at the flying field when you're finished! Good luck!

ELECTRODYNAMICS POW'R BUS PRO With so many digital servos on board, an ElectroDynamics Pow'R Bus Pro system and separate, high-capacity battery packs are used to manage the power requirements. Worry-free servo management The power requirements of the servos needed to control a giant-scale model can be quite high, especially if you use a lot of digital servos-like in the 46% TOC Ultimate. With 15 digital servos at work during each flight, it's best to power the servos and receiver with their own battery packs. The ElectroDynamics EDR-111 Pow'R Bus Pro makes this easy. This compact unit has separate power buses and isolates servo noise and power loads from the receiver. It can handle up to 6 channels (all the flight controls) and provides you with a way to attach a separate battery pack to power only the servos. Separate leads connect the EDR-111 to the receiver. In the Ultimate, two 3200mAh battery packs and two separate switches power the flight-control system. The throttle servo is plugged directly into the receiver and is powered by a third battery pack and switch harness. This system isolates the receiver from heavy power demands as well as from electrical interference that the servos might create with their long servo leads. ElectroDynamics (734) 422-5420; electrodynam.com.