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GREAT PLANES PITTS SPECIAL ARF 
Boy, have I got an aircraft for you!! If you like to do aerobatics that are scale and not fast, but are scale in speed, then the Great Planes 1/3 scale Pitts is the plane for you. And it's IMAA legal to boot. This aircraft comes completely covered with MonoKote and has top quality hardware made for giant scale models with it, which includes a very well designed tail wheel spring mount. It assembles in no time due to an extensive instruction book that guides you through all the required steps. Before you leave the hobby shop or put the phone back on the cradle, you will also want to get a good engine and pilot to go with this beauty. The recommended engine size starts with an O.S. 1.60 FX, a SuperTigre G-4500, O.S. FT-300 Gemini Twin 4 stroke or a U.S. Engines 41 cc gas. I chose a Zenoah G38 for its known power and light weight and a MGA painted pilot bust to go in mine along with a Futaba 7UAF radio system and a scale dash board. As with any aircraft this size, I used heavy duty metal geared servos on all surfaces and a standard servo on the throttle. The bird comes to you with each part packaged in its own plastic bag to protect that beautiful finish, and is provided with a polished spinner and a fuel tank which has a universal stopper and internal fuel line for use on gas or fuel. The first thing I noticed was the quality of the workmanship and the use of outstanding materials. The interplane struts are constructed of fiberglass and streamlined. The cowl is also fiberglass and is very well done. Wheel pants are also glass and all of the glass parts are painted with matching color to the MonoKote. The canopy is painted and ready to trim for attachment to the fuselage. Because I was mounting a 35 cc gas engine on the nose, I did a very thorough inspection of the engine mount area and the surrounding structure. The use of epoxy in and around the engine compartment was readily apparent and makes for a very strong assembly. The firewall is already epoxy coated and sealed. Another decision you will have to make at this point is if you are going to use two aileron servos or four. Both ways have been extensively tested by Great Planes and work quite well. Ok, that makes 4 aileron servos, 2 elevator,1 rudder and 1 engine servo. This has gotten to the point that I am going to use a 6 volt 1800 mAh battery pack instead of the standard battery. Oh well, I might just as well use a dual battery system with a 600mAh standard pack on the receiver and a 6 volt 1800 mAh pack on the servos. This gives me the best of both worlds and gives me the highest rating on the servos for torque. The dual battery system I used is my own design and does not have any active components in it, therefore, it does not use any power. The servo signal from the receiver goes direct to the servos so this unit is compatible with all the radio systems using the S, JR, Futaba or Airtronics Z connections. The kit comes complete with 4-40 clevises and push rods along with pre-cut fuel line for clevis locks. All threaded clevises are metal and have stop nuts provided. Alright, let's plan ahead a little here and start a check list of things I need to keep track of while I build. THIS IS A 1/3 SCALE AIRCRAFT WITH A LARGE ENGINE. USE LOCKTITE ON EVERY FASTENER AND FITTING!!!! Don't take a chance here as it will cost you an aircraft. Also any wood or sheet metal screw mounting must be hardened by applying thin CA to a pre drilled hole. I thread the hole first then harden it. DO NOT use Quickset on the screw holes. After the CA has dried I apply a second coat to the hole and thread the screw in before the glue sets. This acts as a locking device. On screws that you want to remove and reinstall,(ie. Cowl), don't do the second coat as it becomes difficult to remove the screws after the glue sets. Assembly of the craft begins with the ailerons and is a standard hinging operation using CA hinge strips. Again DO NOT use quickset here as it will cause the CA not to wick into the slots as it should. The instruction book tells you to drill a 3/32" hole in the center of the slot to help the glue wick in properly, do it! Make sure that you keep the hinge line as tight as possible and still have the movement called for in the control setup. Less gap means better control in the air. Attach the control horns per the instructions and set the aileron servos up for mounting. After mounting of the servos you will install 4-40 push rods and clevises. Use silver bearing solder to solder the solder clevises to the push rods making very sure you have a clean and fully soldered connection. Use a top quality liquid flux here to assure that you will get good adhesion from the solder. Each wing has a string installed to pull the servo leads through which make it easy to install the servos. I use 22 awg wire on all extensions and Y cables. I also use heat shrink tubing to keep the plugs from ever coming apart during flight or handling. Choose the length of the extensions carefully so that you don't have to much excess lead. You can get 20 awg extensions and Y harnesses from Great Planes under the Hobbico Pro Series. In the case of the upper wing Y harness, I made up my own so that I would not have an extension in line between the servo and the Y. You will be installing an Ernst #124 Charge Receptacle in the top of the fuselage at a later time to plug in the Y connector from the top wing servos. Keep the use of CA to 6 drops per hinge per side as per the instructions. Also you will want to keep a rag handy to clean up any glue runs that may occur. Now back to those servos. Cut out the four servo mounts leaving about 1/8" all around to iron down to the edges of the cutouts. Feed the connections through the wings using the strings and tape them down at the root end of each wing. Install the servos and push rods as directed and you are ready to join the wings together. Start with the bottom wing and assemble the wing joiners as shown. You will end up doing a little sanding to get the joiners to fit but not a lot. Do this carefully so that you have a very snug fit. Use 30 minute epoxy and glue them in place when you have a good fit. Make sure that you have test fit the lower wing dowels before the epoxy cures all the way and that you have a good coat of glue over the entire root rib on both halves. Use alcohol to remove any excess epoxy. You must also check for proper dihedral at this time in the lower wing assembly. Don't leave a gap make sure the wing root ribs are in full contact and clamp or tape the seam until dry. After the wing is dry, attach the wing bolt plate as shown and drill out the holes from the top of the wing. One wing done, now for the top wing. The top wing goes together just as easy as the bottom wing but here you have a center section to contend with. Locate the joiners and again sand them to obtain a snug fit . Trial fit the center section to the outer wing panels and make very sure that it is a good fit. There is no dihedral in the top wing so do the test fit on a flat surface. It is important here to make very sure that the joiners have a tight fit in the center section and the outer wing panels. I had to add a shim to the front joiner to get a good fit on this kit but every thing else was perfect. Use 30 minute epoxy and glue the joiners in place on the wing panels. After the epoxy dries use the string threaded through the center section to pull the servo wires through. Now glue the center section using 30 minute epoxy to the outer wing panel. Do one side at a time and let each side cure before doing the other side. Make sure the outer panel is aligned with the center section and that there are NO gaps. At this point you will be installing mount brackets. Don't assume anything here! Do as the book tells you. And carefully match the brackets with the diagrams. Again I threaded the holes first and then saturated the holes with thin CA, allowed it to dry and then used the CA again and mounted the brackets as described. As with any pre covered model you will have to cut away the covering at certain glue points. When you do this be certain that you do not cut the wood under the covering. A hot knife is a great help here as it takes less pressure to cut the covering. Mount the bottom wing and find the belly pan. Align the pan on the wing and with the fuselage. Use a felt tip pin and mark around the belly pan on the wing. Measure in from your line 1/8" and cut away the covering on the wing only. Use 6 minute epoxy to glue the pan in place. I used lead filled bags to provide weight to hold the belly pan in place until it cured. So far this kit has been about the best I have seen for the way the parts fit and the quality of the hardware used. Hope the rest of it goes as well. Cabane struts are next and again the holes for the wood screws are pre drilled in the fuselage. Again I used the screws to pre thread the holes and then saturated the holes with CA. Make doubly sure that you have these cabanes in proper alignment before you tighten down the screws. After the CA dries attach the top wing to the cabane struts and temporarily support the outer wing panel. You will be fitting the interplane struts next and you must take care to locate the right strut for the right side and the left strut for the left side. Also there is a top and a bottom to these struts. Look at the pictures closely and set the struts on their respective sides on the bottom wing. In the kit that I bought, an early one, and yes I said bought, paid for, I found the measurements given for the mounting of the struts to be correct for the bottom wing and 3/4" off for the top wing. The measurement for the top wing should have been 3 3/4" forward of the trailing edge instead of 3". When you do the struts be sure to use CA in the holes that are drilled for the attachment screws. To assure that the top wing was aligned properly I mounted both bottom struts and set the wing up so that both sides had the same distance between the trailing edge and the back tip of the upper strut seat. I then measured the top wing tip to the center of the tail post for exactly the same distance. After clamping the strut to the forward mount on the top wing, I then marked the struts for the holes, removed the struts and drilled the holes. Make sure here that the wing surface is flush to the top surface of the strut and bolt them in place. RECHECK THE ALIGNMENT BY MEASURING BOTH THE TOP AND BOTTOM WING FROM THE TIPS TO THE CENTER OF THE TAIL POST. TRUE ALIGNMENTS ON THIS BIRD ARE A MUST!! Now you are ready for the horizontal and vertical stabilizers. Set them up as you would with any aircraft and again double check that you are in alignment in all directions. Here again you will have to cut away the covering on both the horizontal and vertical stabs for mounting purposes. The elevators and rudder are attached the same way as the ailerons and once more make sure the gaps are as narrow as possible. In all cases on this aircraft the hinge lines were straight and true and made hinging a piece of cake. After all glue has dried the elevator and rudder servos are next on the "to do list." My radio has mixing and will allow me to use two channels for the elevators. If you don't have this capability on your radio, get a dual servo synchronizer with reversing on it for your radio system. The most precise control will come from both servos operating in the same direction. Also for all the servos on the elevator and rudder, use high output servos with heavy duty glass filled or aluminum arms. I used Hitec HS615MG servos for all three but any high output precision servo will work well here. Extensions with heat shrink were again used and the length was selected to allow me to twist all the leads together for a neat installation. On the tail plane struts, instead of using cable, I opted for 4-40 pushrood and clevises. This was a personal choice. Next to install is the tail wheel gear and tail wheel. Again everything you will need is provided in the kit and is top quality. The hookup to the rudder servo for tail wheel steering is different but is easy to accomplish if you follow the book. Mount the main gear to the fuselage and install the landing gear cover and you have an aircraft ready to set on its gear. Now we are going to mount the landing gear spats, wheel pants and wheels. Nothing difficult here and very well laid out in the directions. Now mount your engine. As I used a Zenoah G38 I did not have to use the plastic motor mount supplied in the kit. I drilled four holes at the proper locations and mounted blind nuts on the firewall. Here again I used thin CA to harden the wood around the blind nuts and then used epoxy to hold the blind nuts in place. Installation of the fuel tank had no problems at all. The book advises to use silicone to secure the tank in place and I did just that. Here I deviated from the manual again. As I am installing a gas engine with a magneto ignition, I decided to move the throttle servo back into the aircraft instead of mounting it up on the engine mount box to eliminate any possibility of noise getting in the system. I used Sullivan golden rod to connect the throttle to the servo. Next comes the cowl. This is a beautifully done cowl and well deserves a few extra minutes of time to do a good job of matching the cutouts to your engine installation. The manual gives a very good way to obtain the correct cutout position and also the mounting screw locations. Wow, it's an airplane, Well almost. I have to mount the spinner and prop, receiver, switch harness, and upper wing aileron servo connection in the fuse. Also have the flying wires to do and the support struts on the tail group. And battery installation. Choose the battery location carefully and you will not have to add any weight to this aircraft to get it to balance. I again made a change to the aircraft at this point by moving the antenna away from the servos in the rear and making sure the antenna was stretched out to its full length. The pre-installed antenna tube in the aircraft went right down the middle between the servos and the antenna did not exit the aircraft in the rear. This is not the way that I prefer and a reroute was done. The suggested means of hooking up the top wing servos is to use a Ernst #124 charge receptacle that has been cut down to accept the female end of an extension. Use a 20 or 22 awg extension for this and make it 24" long. Mount it in the top of the fuselage next to the cabane strut and you have a very clean way to make and break the connection to the top wing. The flying wires are not functional but add that scale appearance. They are easy to make up and all the material you need is supplied with the kit. Another change I did here was to make the wires longer than stated in the kit to make them easer to make up. Instead of cutting 21 inches I made them 28 inches. There was plenty of wire in the kit for this. Just follow the directions and it won't take you very long at all. All of the parts for the flying wires are top notch and make for a very clean installation. The spinner that is supplied with this kit is of a design that I haven't seen, but seems to work very well. It is highly polished and I used my cotton gloves every time I had to handle it. It installs just like any other spinner with the exception of the spinner mounting screw. There is a bracket attached to the back plate which has the nut welded in the top for the spinner bolt. I used a large starter on the engine and saw no slippage what so ever from the spinner. I used a Pro Zinger 18-10 prop and got 7200 RPM from the G-38 when I did the test run up after completion. As I said at the beginning I bought a dash board and installed it in the aircraft after I painted the interior flat black. I mounted the pilot in the aircraft and proceeded with the next step. Here the manual says to glue the canopy on but I decided to use screws instead. I added 1/8" ply blocks to the inside of the cockpit rim and again did the pre drill, thread and harden thing. Apply the decals if desired at this point. All right, let's do the control setup and we will be done. All throws are listed for you and if you set everything up as stated you will have a very good first flight. Use a deflection gauge to measure the throws and do it at the location stated in the manual. C/G was listed at 5" to 5 3/4" back from the leading edge with the ideal at 5 3/8". After locating the batteries to obtain this balance point, I mounted them to the airframe and then rechecked the balance. No lead, this is great. Be sure to balance the craft laterally. I had to add 3 ounces to one panel to get the bird to balance level. Triple check everything on the model and put a full charge on the batteries and it's off to the flying field for that first flight. This bird draws attention as soon as it comes out of the vehicle. It's big, it's beautiful and it's hard to miss with that bright red covering. You can see from the smile on my face that I am very pleased with what I have. The G-38 fired on the third flip and I did a range check with the antenna down. Ok, now to try the bird out. A slow taxi out to check the steering and a check on ground handling. Excellent. Back to the end of the runway and start easing in that power, tail raised within 10 feet and the craft was tracking straight down the runway with very little correction on my part. Smooth liftoff and a very good climb out, leveled the bird and check the trim. One click aileron and one click elevator. Great! No bad habits at all to this point and a smooth flyer to boot. This baby stays where you put it and it gets there smoothly. This is a great flying bird and you will enjoy the way this aircraft handles. Specifications as built: July/August 2002 R/C Excellence Editor: Fran Smith
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