 |
|
 |
|
|
|
|
          |
            |
 |
GREAT PLANES TRACER 
SPECIFICATIONS RCM PROTOTYPE SUMMARY  Are you looking for a sportsman pattern kit? Well look no further, Great Planes Model Manufacturing Company has produced the Tracer kit. It's a good looking, superb flying, .40 size Sportsman Pattern model for R/C pilots who enjoy Precision Aerobatics. Our kit arrived in a very colorful box measuring 48-3/4" x 7-1/2" x 4-1/2". The contents were inspected and everything appeared to be neatly packed and nothing was cracked or broken. The clear plastic canopy and the ABS plastic cowl were in protective wrap. A good assortment of hardware was contained within a plastic bag. Again, Great Planes has taken the time to include lengths of fuel tubing that will act as safety keepers over the clevis. Making use of these little safety items may make the difference between a successful flight and a total wipe out. The full-size plans were unrolled and re-rolled inside out so they would lie flat on the work surface. Each plan was checked to see if there were any significant differences from normal building practices. To make the plans easier to work with, the stabilizer and fin drawings were cut from the 36" x 50" fuselage plan. The plan was then covered with Great Planes Clear Plan Protector. The remainder of the fuselage plan and the slightly smaller wing plan, 36" x 46", were set aside. The die-cut sheets were laid out and all parts were verified and marked using the 48 page Tracer instruction manual. We noted that Great Planes' designers had engineered several final assemblies by laminating die-cut piece parts together. This makes a strong assembly, but depending upon the amount of adhesive that is used, can also add weight to the model. Wood sheeting was sorted for the stab covering, wing leading and trailing edges, and for fuselage decking. It was noticed that the 1/16" x 3" x 30" wing sheeting was not consistent, some sheets were hard and some were very soft. We set the sheeting aside and starting marking the die-cut parts prior to punching them out. Most of the die-cut parts just fell out; the rest needed only a little pressure.  Construction: For assembly we used Great Planes Pro CA's, epoxy, and a variety of their modeling tools. Tail Surfaces: Following the Tracer instruction manual, we built the stabilizer, elevator, fin, and rudder using the recommended CA. The built-up surfaces were flat-sanded using the 22" Easy Touch Sander. We then cemented the 1/16" balsa stab sheeting with aliphatic resin glue and applied weights to keep everything straight and true. When the cement was dry, the tail surfaces were again sanded, the leading edges rounded off and a slight taper to the trailing edge. Wing: The wing plan was cut, covered with the Plan Protector, and laid out on the work surface. We had planned to install fixed gear, so when we completed step 13, we skipped the instructions for the retractable gear and continued building with step 21. At this point, we needed to select the 1/16" sheeting for the wing leading and trailing edges. As previously mentioned, some of the sheeting appeared to be too soft or too hard. We elected to purchase additional 1/16" x 3" x 36" balsa sheets and replace two of the 30" kit pieces. The remainder of the right wing was constructed per the instruction manual and then the left wing was built. Following the "Join The Wing Panels" steps in the instruction manual, the two wing halves were assembled using 30-minute epoxy. The wing was then set up per "Finish The Top Of The Wing" and the 1/16" leading edge and trailing edges were attached using a combination of thick CA and aliphatic resin glue. Slots were cut for the landing gear, the openings for the servos and a hole was cut in the center section sheeting for access to the servo leads. Hinging: Hinge locations were marked on the wing, ailerons, rudder, fin, stab, and elevators. We always left this chore until the last step. We had tried the alignment jigs and #11 X-Acto knife blade, thinned down saw blades and hook-tip knife blades. Our success rate of cutting a "good" hinge slot was about 60%. That is, until we purchased the Great Planes Slot Machine. What was once a dreaded task was now simple, fast, and best of all, 100% accurate. In no time at all, hinge slots were cut and the hinges were temporarily installed in all surfaces with perfect alignment. Fuselage: The die-cut plywood formers were trial-fitted and then cemented using 30-minute epoxy. Heavy duty binder clips and plastic clothespins were used to clamp everything together to prevent warping. After the epoxy had cured, the F-2 former and the F-1 firewall was marked per the instruction manual and all holes drilled for the fuel line outlets and the 6-32 blind nuts to attach the supplied adjustable engine mount. 3/16" holes were drilled in formers F-4A and F-5A to guide the plastic pushrod tubes. Note: the fuselage is built upside-down, right over the bottom view of the full-size plan. It is very important that each assembled part is straight and true. We aligned the top edge of the fuselage sides with a 36" heavy-duty steel rule prior to applying the CA. The 1/8" balsa die-cut sides, top, and bottom pieces were marked and aligned to the straightedge and then assembled using medium CA. The fuselage formers are aligned on the upside-down fuselage top, the sides are put into place and then the bottom is installed forming a very strong "box" type lower section of the fuselage. The bolt block is assembled from the three 1/8" die-cut plywood pieces epoxied together and then epoxied into the fuselage. From here, the belly pan is built and fitted to the wing, the wing is centered, mounting holes are drilled and tapped for the 1/4"-20 nylon hold-down bolts and the bolt guides are installed. Everything was checked for alignment, then we removed the lower fuselage half from the building surface. The upper sections of the fuselage were completed per the Tracer instruction manual. The turtledeck top was rough shaped using a Windsor Master Airscrew Razor Plane, then the entire fuselage was sanded. There were several little "dings" that needed attention. We used two methods, wet the ding with water and "steam" the dent out using a MonoKote iron. On others, we used Red Devil "light" filler from the local paint store. This filler goes on easy, sets up fast, is lightweight, and sands easier than balsa. Again, our Easy Touch Bar Sanders made the task a lot easier. Following the steps in the instruction manual, the stabilizer and fin were attached to the fuselage using epoxy. Engine: Due to the wide range of weather conditions in this part of the country, we elected to install a good running SuperTigre .51 for power. The kit-supplied engine mount was adjusted to fit our engine, drilled and tapped for 6-32 bolts and our engine was installed. Radio: For control, we used a JR 388 radio system with five JR 507 servos (two for ailerons and one each for rudder, elevator and throttle). Using the kit-supplied hardware, installation was quick and easy, and there is adequate room for all equipment. The ABS plastic cowl was cut out and assembled using medium thick CA. Lightweight fiberglass cloth was then laid across the seam on the inside of the two halves and all around the cowl mounting areas. Thin CA was then saturated into the cloth. Holes were cut to fit our engine, the outside seam was filled with plastic putty, and the cowl was sanded smooth. The first coat of Top Flite LusterKote primer was applied and the cowling was set aside. Covering: Before the framework can be covered, it must be cleaned of sanding dust. We first used a soft brush on the vacuum hose and thoroughly brushed off the entire framework. We then used 2 inch wide masking tape as a "tack cloth" and patted all the sheeted surfaces as an extra precaution against balsa dust. We selected Top Flight Super MonoKote for covering material. The entire model was covered in white and red. We then cut designs from the red, yellow, and dark blue for our trim. Using a mixture of 3-4 drops of liquid dish soap and 5-6 ounces of water, we smeared the soapy solution on the wing, applied the Super MonoKote and moved it into position, then using a plastic credit card, squeezed all the soapy water out from under that piece of trim. We smeared the wing with soapy water again and placed another piece of colored Super MonoKote into place. We continued until the top of the wing had all the MonoKote on MonoKote in place. We then allowed the wing to dry for at least 24 hours while we decorated other areas of the model using the same method. The next day, using our MonoKote iron set to a slightly lower temperature, we sealed all of the edges of the color trim. The result, no bubbles! Amazing, and it only took 30 years of practice to find out how to do it. We spray-painted the cowling with Top Flight LusterKote white with red trim.  Finishing: A 10 oz. fuel tank was placed into position and the fuel lines were inserted through the pre-drilled holes in the firewall. With the Super Tigre .51 mounted inverted, the position of the fuel lines and the tank was much too high. The tank and the fuel lines had to be moved down about one inch. We removed the engine mount and re-drilled the holes for the fuel lines so that they would line up with the carburetor of the inverted engine. With all the radio equipment installed, our model came out slightly nose heavy. A larger tail wheel was installed and our model set perfectly on the balance points. A small weight was added to the right wingtip to balance the model laterally. All-up weight, ready for fuel, tipped the scale at 5.5 lbs.  Flying: Why is it that when you finish up your latest project, the weather turns rotten? Almost two solid months of snow, ice, rain, and or wind. At last we had a break in the weather and everything was set to go. At the field, our Tracer was examined by our peers and after all the usual questions, we were ready to perform the test flight. With the frequency pin attached to the transmitter and a range check completed, the tank was filled and our model was placed into the holding fixture. Our Super Tigre started with just a touch of the electric starter and the needle valves were set. A few quick throttle checks and we were ready. The taxi out to the runway was uneventful, good ground handling and easy steering. Acceleration was quick, tracking was straight and true down the center of the runway. After about 150' run, lift-off was very smooth with only light back pressure on the stick. Climb-out was easy, as a matter of fact, it was fast. One click of up elevator and one click of right aileron was enough to provide "hands-off" flying. Our Tracer performed all the usual AMA Sportsman Pattern maneuvers with ease. After several minutes of high speed and low speed tests, the landing approach was set up. Final was smooth and predictable, glide angle good, and touchdown was a sight to behold. Now for the real test: Mike McMurtry, National and International Pattern Contest winner, put our Tracer through the wringer with every known and maybe unknown maneuver that a well designed "Pattern model" should be able to perform, including vertical acceleration that just wouldn't quit. Watching Mike fly a Pattern model is like watching a fine ballet. Needless to say, his landing was just as good as mine. We all agree, this .40 size model is "superb in design and flight performance." Photos by Ken Kehlet & Bob Musewicz. Reprinted with permission.April, 2002 R/C Modeler Magazine Editor: Dick Kidd
|
|
 |
