 |
|
 |
|
|
|
|
          |
            |
 |
GREAT PLANES TRACER 
SPECIFICATIONS Hits
Misses
.46-size sport pattern aerobatThe Great Planes Tracer is a .46-size entry-level pattern airplane that will surely make learning how to fly pattern maneuvers much easier for the average sport flier. The Tracer is almost as fun to build as it is to fly, and Great Planes supplies just about everything you need to frame it up. The kit includes high-quality balsa and lite-ply and a complete hardware package. You need only a .40 to .51 2-stroke or a .52 to .70 4-stroke engine, a 4- or 5-channel radio with six servos, wheels, a radio, covering and glue; retracts are available separately. The Tracer also comes with a well-illustrated instruction manual. Construction Begin construction with the tail feathers. Build the stab over the plans using die-cut center sections and a die-cut stab leading-edge (LE) support. Pin the center section and LE support over the plan then cut the outer framework and ribs and pin them into place. Secure the framework in place with a few drops of thin CA. After the glue has dried, lightly sand the stab top and bottom to remove any high spots and then sheet the framework. To make the elevators, simply cut the tapered stock to match the plan, and sand a "V" on the LE. The fin and rudder are constructed in much the same way as the stab. Simply cut the outer frame of the fin and rudder and the ribs and corner gussets, pin them to the plan and secure them with thin CA. I like to sand the fin and rudder at the same time to ensure they're of the same thickness. Wing Construction First, you must decide whether you want to install retracts or fixed gear; the manual gives instructions for both. I decided to install the Hobbico retracts in my Tracer. The first step is to punch out the die-cut parts. The die cutting on the lite-ply doublers was not very crisp, and quite a bit of cutting with a no. 11 blade was required to free the parts. I also had a problem with four of the ribs; they had wavy airfoil contours from the main spar to the trailing edge (TE), and I had to make new ones. The next step is to build up the spars by gluing four 1/8x3/8x14 1/2-inch-long basswood spar doublers to four 1/8x3/8x30-inch basswood spars. Because I built the retract version, the next step was to glue the 1/8-inch plywood retract rib doublers to the corresponding 3/32-inch balsa ribs, then frame up the wing over the plan upside-down, one panel at a time. Place one aileron servo in each wing panel, then glue the 1/8-inch-ply servo mount and servo-mount support into place. Each wing panel contains five shear webs, which are made from 1/16x3x24-inch balsa sheet. The LEs are preshaped and must be cut apart before you glue them into place. Be sure to align all of the spars, LE and TE parts with the wing centerline before you glue them. Retract Installation The Hobbico main-gear retracts are very easy to install in the wing panels. Cut the gear legs to the length shown in the manual and attach Great Planes adjustable axles to the legs along with 2-inch wheels. Screw the completed unit to the basswood retract rails that are glued into the notches in the gear ribs. The plan shows a full-size template for bending the retract pushrods, which are made from two 12-inch Great Planes pushrods. Attach the pushrod to the retract and make certain that nothing binds it or restricts its operation. Remove the retract from the wing panel, and glue the bottom LE and TE sheeting into place with thick CA. Unpin the wing panel and very carefully cut openings in the LE sheeting to accept the retract body. Lay the retract on the rails, draw around the wheel and gear leg with a pencil and carefully cut away the sheeting so that the unit fits in nicely; make sure there is ample clearance so the wheel and gear leg do not bind during operation. The instructions show how to make a wheel well out of 1/32-inch ply wrapped around a soft-drink can. Center the wheel well around the wheel and glue it to the LE sheeting, spars and LE. Remove the retract again and trim the sheet flush with the inside of the wheel well, then block-sand the top of the wheel well so it's flush with the ribs on each side of it. That's it! It isn't much more work than installing fixed gear, and it's well worth the extra time. Join the framed-up wing panels with a wing joiner that is laminated together from three 1/8-inch-ply die-cut pieces. Two wingtip jigs and a center-joint jig help keep the panel straight while the epoxy dries on the center joint. With the wing still on the jigs, glue the retract servo mount, the top sheeting and the capstrips into place. This will result in a perfectly straight wing. When all of the sheeting has been trimmed, glue the forward dowel support into place with the two dowels. The ailerons, aileron-tip and aileron-center pieces are made from tapered aileron stock. Cap the wingtips with leftover 1/16-inch balsa sheet. Glue the aileron-center and aileron-tip pieces into place, and cut the ailerons so there is about 3/32-inch clearance on each end. Hinge the ailerons without gluing, and sand the entire wing smooth. The wing goes together very quickly; it probably took me less time to build it than to write about it. Fuselage The fuselage is constructed primarily of 1/8-inch die-cut lite-ply formers and 1/8-inch die-cut balsa. The top front and turtle deck are formed with 1/8x1/4-inch stringers. The first step is to put together the subassemblies. Glue the two formers together to make up the firewall. An 1/8-inch-ply plate glued to the back of the firewall holds the blind nuts for the motor mount. Stamp punch marks on the front of the firewall to indicate where the mounting screws, fuel lines and throttle cable holes go. The fuselage sides are made from three die-stamp pieces; the top is made from two die-stamp pieces. This is where I ran into some difficulty. The die-cut pieces did not fit together properly, and it took some time to get the pieces to match the blueprint. In addition, the sheets of balsa that the parts were stamped from varied in thickness, and this created extra work when it came time to fit and sand the bulkheads. After you glue the fuselage sides together, glue 1/8-inch plywood doublers into place to form a left and a right side. The doublers run from the front of the fuselage to behind the TE. The fuselage doublers have slots of different sizes stamped into them that help to locate the firewall with the proper amount of right thrust. Be sure to glue the doublers to the proper fuselage sides. Glue the bulkheads into the notches in the top of the fuselage. Use a square to hold the bulkheads 90 degrees to the top of the fuselage when you glue them. Now, glue the sides of the fuselage to the top and to the bulkheads; use the notches in the top to properly align the sides with the bulkheads. Next, glue the fuselage bottom into place. When I unpinned the fuselage from the workbench, I noticed that the top was not as wide as the sides. This left me with a gap around the fuselage of about 1/64x1/8 inch that had to be filled in after I had sheeted the turtle deck and fuselage top. Following the plans, mount the wing to the fuselage and glue a belly pan to the bottom of the wing. The rest of the fuselage is pretty much straightforward. Sub- bulkheads and stringers that are sheeted with 3/36-inch balsa form the top shape of the fuselage. Sand the fuselage one final time, then bolt on the wing and glue the stabilizer and fin into place. As long as you follow the instructions, everything will come out straight, and you will have an airplane that requires no trim and that tracks straight through every maneuver. Engine and Cowl I chose the recommended O.S. .46 FX for my Tracer; it proved to be the perfect power plant. I attached the supplied mount to the firewall with the supplied 6-32 screws and adjusted it to fit my engine. I used my Great Planes Dead Center En-gine Mount Hole Locator to mark the location of the holes, then drilled and tapped the mount to accept 6-32 socket-head bolts. The cowl is vacuum-formed ABS plastic and must be cut along the provided lines. Glue the cowl halves together with thin CA and reinforce the in-side joint with scraped ABS sheet. The engineers at Great Planes provide cut lines molded into the cowl sides, and these make it much easier to locate all the cowl openings (provided you are using the O.S. .46 FX engine). Scribed lines indicate where you should cut the exhaust exit, air intake, glow-plug hole and even the wrench holes for access to the muffler screws. Four sheet-metal screws hold the cowl on the fuselage. Radio Installation The die-cut plywood servo tray fits a variety of servos. Mount the aileron servos in the left and right wing panels then feed the servo wires through the hole in the top center section. Connect the ailerons to the servo arms with the provided control horns and the pushrod wire. Screw the Hobbico low-profile retract servo into its built-in tray and connect it to the pushrod with the provided screw-lock connectors. Drill holes through the bulkheads and fuselage to guide the elevator, throttle, rudder and antenna through the fuselage then glue them into place. This makes setting up the pushrod wires very simple and bind-free. After the pushrod tubes have been glued in, epoxy the 1/8-inch-ply servo tray into place. The control surfaces are connected to the servos with the supplied 1/16-inch pushrod wire. Fast-link connectors secure the pushrod wires to the servo arms, and the throttle connection uses a screw-lock connector. Balancing It is very important to balance the model—not only on the correct center of gravity but also laterally. I had to add 6 ounces of lead to the rear of the fuselage to achieve the balance shown on the plan; the lateral balance was fine. Covering and Painting I chose to cover my model with Top Flite MonoKote. When I had finished covering the model, I installed the supplied CA hinges. I trimmed the canopy to the cut lines and glued it into place. Remember to remove the covering materials around the canopy area where you want the glue to stick. I used slow-curing epoxy to hold my canopy in place and secured it with low-tack drafting tape until the glue had dried. Conclusion Even though the review kit required some extra work, it was well worth it. The Tracer is one of the sweetest flying airplanes that I own, and I know that anyone who builds one will be thoroughly pleased. Keep up the good work, Great Planes! FLIGHT PERFORMANCE Takeoff and landing - After starting the engine, I taxied the Tracer out to the runway and checked the ground handling. Even with its low ground clearance, the Tracer maneuvered very well with no tendency to nose over in tall grass. I pointed the model into the wind, and it was airborne before I reached full throttle. I didn't even need any trim corrections when I retracted the landing gear. When I landed the plane, it slowed to a crawl with no sign of sluggish control. As a matter of fact, I was so impressed with how it flew at landing speed that I nearly forgot to put the gear down. Low-speed performance - The Tracer exhibits exceptional low-speed performance. When the wings are level, you can chop the throttle and nose the airplane up, and it will stop and fall nose-down without snap rolling. At 1/4 throttle, the airplane will still do rolls and loops and will fly inverted. It probably flies better at low throttle than some 60-size pattern ships do at full throttle. High-speed performance - I was really impressed with the Tracer's speed. With the O.S. FX .46 swinging an 11x6 prop, the Tracer is a real bullet in the air. It retains its nice, stable flight characteristics. Aerobatics - The Tracer is designed to perform aerobatics. In the hands of a capable pilot, it would be competitive in almost any pattern contest. The Tracer tracks straight through inside and outside loops, and it's barely affected by a crosswind. Rolls do not require much elevator input, and snap rolls are very crisp. The Tracer also stops the roll wherever you center the sticks. The airplane is so clean that to do a stall turn, you must throttle down way in advance of pulling up; it then climbs like a rocket before it bleeds off airspeed.
November, 2001 Model Airplane News Editor: Gerry Yarrish
|
|
 |
