Sportsman Aviation: Paramount 60 Freestyle ARF

Model Airplane News, May 2004 by Luciano, Carmen

Versatile .60-size 3D aerobat

Distributed by Global Hobby, Sportsman Aviation's products are geared to experienced modelers. Its Paramount 60 Freestyle ARF adds a new dimension to the freestyle 3D airplanes that are flourishing In the RC market. This midsize aerobat is easy to transport, and its 3D maneuvers will dazzle you and challenge your dexterity, ingenuity and imagination.

The ARF plane can be assembled in fewer than 18 hours. Its components are well constructed of balsa, lite-ply and fiberglass. A fiberglass engine mount, cowl and wheel pants, a canopy and good-quality hardware package are provided. The iron-on covering was flawless, so I did not have to heat-shrink any part of it.

ASSEMBLY

* Wing and tail. All the hinge slots had been cut at the factory, and I didn't have to enlarge them. The instructions tell you to glue the precut CA hinges to the ailerons and then to the wing. Remember to match the color scheme (the tops of the wing and aileron are red; the bottoms are blue). Remove a thin strip of covering from the hinge slots to ensure better adhesion. I suggest that you remove this strip of covering from the bottom of the slots so it will not be visible from the top surface; this may not improve performance, but it will certainly look better.

Installing the aileron servos in each wing half was easy with the pull-through strings provided in the wing. The JR 531 servos fit neatly into each wing's servo tray. They sit low and flush with the wing chord-a nice touch.

The next job was to join the wing panels. Note the orientation of the dihedral brace; a slight dihedral is built into the wing.

I attached the horns and pushrods to the ailerons with the supplied clevises and pushrod keepers. Then I aligned the stabilizer and glued it to the fuselage slot. The factory prep was precise, and I didn't have to trim or shim the stabilizer-mounting slot in the fuselage. I installed the tailwheel assembly in the rudder and affixed it to the sub-dorsal fin on the fuselage for strength and stability. I hinged the elevator and rudder in the same way as I hinged the ailerons. I attached the large threaded horns to the rudder for the pull-pull setup and placed the elevator horns on each side for the split pushrod assembly.

* Servos, cables and pushrods. I installed ball-bearing Hitec servos for the rudder and elevator and a standard Hitec servo for the throttle. They fit neatly in their own compartment in the fuselage, aft of the wing's trailing edge. Installing the removable hatch on the fuselage bottom completed the radio installation.

Follow the dimensions given in the manual when you cut the exit slots in the aft fuselage for the rudder pull-pull cables and the split elevator pushrod. They line up accurately for great control-surface response. When you get to step 20, which deals with the rudder pull-pull cables, I advise that you complete the tasks in a different order from the one given. The manual tells you to crimp the cable at the rudder horn first and then make adjustments at the servo, but this would make things difficult because the servo is deep inside the fuselage, and there isn't a lot of room. I suggest that you secure and crimp the cable at the servo first, and then run the cables to their aft exit slot, and make your adjustments at the rudder horn, where you will have plenty of room to maneuver your tools.

Next, I assembled the split pushrod for the elevator. A balsa dowel, three wires of the appropriate size and shrink-tubing come in the kit. It wasn't easy to install this system or to balance the split elevators' movements. (This is the only hardware I consider to be below par.) With patience and mechanical adjustments, however, I succeeded in making it work.

* Engine and cowl. At first glance, I thought the directions for this section were awkward and would make the fuselage/cowl alignment difficult. If you follow the steps exactly, however, and use double-stick tape to hold the fuselage vertical, it's easy. The firewall, engine mounts and cowl are angled to accommodate the engine's right thrust. On the fiberglass cowl, I drew the outlines of the openings required for the engine and then cut the openings with a rotary tool. I enlarged the | bottom opening for the glow plug to allow a better airflow. The outward airflow keeps the engine cool, and for proper cooling, the outward flow should be three or four times greater than the inward flow.

I marked the position of the throttle pushrod on the firewall and drilled the outer pushrod-tube hole. Last, with the engine inverted, I attached the throttle pushrod and the .61 Magnum 2-stroke to the mounts. I fastened the cowl to the fuselage with washer-head screws. Remember to make the holes in the cowl slightly larger than the screws' diameters to avoid the creation of "stress risers"-small cracks in the fiberglass that will lead to larger cracks.

* Back to the wing. To complete the wing, glue the two leading-edge dowels into the predrilled holes and install the blind nuts in the fuselage wing-mounting plate. Then align, glue and drill the plywood wing-bolt reinforcement plate and attach the lower wing fairing.