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Below you'll find a collection of handy modelling hints on areas such as engines, fuel, prop choices, building ideas and techniques, bush mechanics and HEAPS more! There is quite a bit of knowledge on this page, but it's only the tip of the iceberg when it comes to what's out there with our experienced club members! |
Fuel Soaked? For fuel soaked fusalages, try mixing baking powder and rubbing alcohol in to a paste. Apply a generous coating of the paste to the fuel soaked area and allow to dry for a couple of days. As the mixture dries, it will absorb much of the fuel out of the wood. Clean off the area with a stiff brush and fuel proof using your favorite method. For wood that has started to deteriate, the best repair is still replacement. Removing Exhaust Residue off a Model This is a great "recipie" for a cheap cleaner that cuts through the grime and leaves surfaces nice and clean! Emergency Screw Driver Not recommended as general practice, but in an emergency - a modelling knife with the blade reversed in the chuck may suffice for light screws. Sanding Files Collect a few hardware paint stirring sticks. Then glue strips of various grade sand papers to each side to create a collection of usefule sandpaper "files". You can also cut the sticks into odd shapes before applying the sandpaper for those hard to reach areas. Cutting Fiberglass Cloth The next time you have to cut fiberglass cloth, try putting it between two pieces of waxed paper. The waxed paper will prevent it from pulling and fraying during the cutting. Running out of fuel! Are you paranoid about running out of gas? Timers,bells,six maneuvers and it’s time to land? What scares you about running out of gas? If your instructor was anybody, he did a few dead-stick landings with you , so what is it? I think it is the possibility of running out of gas on the take-off. We’re all able to handle it if we got enough altitude or ideally on the approach. So how do I get my plane to run out on the approach and not the take- off? Raise the back of the fuel tank up a 1/2" or 3/4". Generally your tank is horizontal with the thrust line and the pick up is in the back of the tank, and sure enough when the tank runs out , you are climbing.By raising the back of the tank, in the climb out, you’ll have fuel and when your getting low on fuel, on the approach (or in straight level flight) your pick up will lose the fuel that is puddle in the front of the tank. you will experience and overall less time in the air, but you’ll be more comfortable running it to the limit. High Grip Spinner Cup The usual spinner cup contacts only a narrow ring that can slip and “burn” a spinner. To provide more gripping area fill the starter cup with silicone rubber, then press the lightly greased spinner into it, and leave it to set. Ensure that the spinner is centred properly. After removing the spinner, wash the grease out with alcohol. You can make these custom adapters to fit your other spinners of different shapes and sizes. Engine Operation If Engine RPM drops more than 200-300 RPM after battery removal then either the glow plug is too cold or the nitro conent in the fuel is too low. Reliable idle is around 3000 RPM with glow engines. On some engines it is possible to get to 2200. Short glow plugs are for engines in the .15 to .25 cu displacement range and smaller. Color Code your fuel lines. There can be up to 3 fuel lines running in and out of a fuel tank. A pickup line, a pressure line and in some cases a filler line. If you colour code the fuel lines and make a note of the colours when you install your tank, they will be easy to identify if disconnected from the engine, the muffler or both. General Tips Learn to fly on a PC then fly using a "Buddy Box" system at the field. Replace your batters every two years. Also paint on them the date they were purchased! Engine Break-In Tips Breaking in an ABC (Aluminum Bronze Chrome) engine takes around 1 hour. When bench breaking it in use the same type of prop as what will be used when flown. Ringed engines use a prop 1" smaller in diameter than what is normal when flown. Ringed engines take 2 to 3 hours to break in. Reliable Idle You should be able to get a reliable idle of an R/C 2 cycle engine at 3,000 RPM. Sometimes you can get it down to 2,200 RPM. Adjust the idle with the glow starter attached, take it off, wait a minute, before seeing if it will not lean or flood when the throttle is moved. Basic Props to use by Engine Size OS 1.08 Zinger 14 x 8 APC 15 x 8 Physics Formula for speed: PITCH * RPM / 1060 Note: It does not matter what the diameter of the prop is! The above formula will show the theoretical maximum speed that will the prop can travel through the air (in mph) for any prop size - - from a 1" diameter to a 12 foot diameter prop! RC 4-Stroke Engine Operation and Maintenance Guidelines High Speed needle valve should be set so the engine runs 400 to 500 below peak RPM Once at Idle: Running Ever So Slightly Rich Always ensure a four-stroke engine runs slightly rich. An engine will lean in the air and too lean of an engine will cause detonation and will likely throw the prop (along with the hub, prop washer, nut somewhere off to the side or front of the aircraft - about where you are!) Adjust it to be another 100 RPM lower (richer fuel feed) when in dry cooler weather. Post and Pre-Flight Checks Check prop nut and safety nut is tight before every flight. After the initial 10 hours of running a new engine check the engine to ensure nothing is loose. Thereafter do an "annual" on the engine every 10 hours of running time to check for lose or worn exterior parts. Once it reaches 50 hours of running tear it apart and check everything. (If you do not have a good clean undisturbed place to take apart and leave the many many little pieces of an engine lying around for a few weeks, send it off to a repair shop.) Glow Plugs The OS Type "F" is a long plug. This was the first out specifically for 4-strokes. It, and the many other brands now out there, being longer it extended into the combustion chamber thus getting and staying hotter. This allows it to retain its glow during the three strokes that the engine is getting ready to fire on the 4th. Never use a "long" plug on 2 cycle glows below 1.2 CU. The piston may hit a long plug unless the manufacturer of the engine specifically states that you can. Fuel As a general rule for running 2 and 4 stroke engines a mix of between 5%-15% nitro and 18%-20% oil will suffice for general flying. Props Like fuel so many choices. Keep the RPM between 9,000 and 11,000 RPM (rough area where most reach peak horsepower) and it should fly well. After Run Oil Owners choice. Air Tool Oil works, as does Marvel Mystery Oil, Mobile 1, Synthetic Engine Oil Sealing Iron on Covering Use polyurethane along the edges of iron on coverings. A thin coat of clear will weld them together. Plane Bean Bags for transportation Engine Break in Procedures Most engines produced today do not require a prolonged break-in period. Refer to a prop chart to determine the proper propeller size for break-in. With the propeller installed securely to the engine, the glow plug installed, the fuel lines connected, and the tank filled with fuel, the break-in operations can begin. The idle mixture screw and/or idle stop screw should not be adjusted during the initial break-in period. This will only serve to complicate the process. All adjustments during break-in will be made to the needle valve. The initial setting is made by turning the needle valve clockwise until resistance is felt. This is the fully closed position. Forcing the needle valve beyond this point can damage the carburetor. The needle valve is then turned counter-clockwise about 2 - 2 1/2 turns to open the port to good starting point. Using the transmitter or throttle pushrod, the throttle is opened to 1/2 to 3/4. Without the glow plug battery connected, a finger is placed over the carburetor opening and the propeller is rotated counter-clockwise 2 - 3 turns or until fuel flows through the fuel line into the carburetor. A 1.5 volt ignition battery or power panel is connected to the glow plug. The throttle opening is then reduced to 1/4 - 1/2 open. The propeller is the flipped counter-clockwise using a "chicken stick" or electric starter. The engine should fire after a few seconds. After the engine starts, leave the glow plug battery connected and advance the throttle to full open. At this point, the engine should be running very rich, i.e. dense smoke and/or heavy oil residue coming from the exhaust. After the engine runs for a minute or two, the needle valve is closed 1/4 turn clockwise and the glow plug clip is disconnected. The engine should be allowed to consume the entire tank of fuel at this needle setting, making sure the engine remains rich. After the first tank of fuel is depleted, the engine should be allowed to cool for a few minutes. During the second tank of fuel, the engine is run at alternate throttle settings, 1/2 throttle for 30 seconds, full throttle for 30 seconds, and back to 1/2 throttle, until about half the fuel is consumed. At this point, the throttle is slowly advanced to full and the needle valve is closed slowly, about 1/8 turn at a time, until maximum revolutions are reached. Finally, the needle setting is turned about 1/8 turn counter-clockwise to avoid an overly lean running condition and the balance is consumed. The engine is allowed to cool again and the tank is refilled. Without resetting the needle valve, a third tank of fuel is run through the engine while alternating the throttle position ever 30 seconds to 1 minute between 1/4, 1/2, 3/4 and full throttle. At this point, the engine is ready for the first flight. The engine is not broken in completely at this point so care must be taken to avoid running the engine overly lean. Engine Owners Manual Read the Owners Manual (RTFM) for your engine to learn everything about your new motor that you can. If the motor was bought used, try looking it up at the manufactures web-site links on our site for more detail. You should also be able to get a copy or send away for one through your local hobby dealer for a nominal price. New Motors If the motor is new, always break the motor in before using it to fly. Many new modelers (and seasoned alike) have lost a plane due to flameout of a new engine that wasn’t properly broken in. Test Stand Break your motor in on a test stand. This will allow you to control the situation much better than in your model. Nothing is more frustrating then installing your motor in a plane just to find out there is a manufactures defect and it must be taken back to the store or sent in for repair. Used Motors You've Just Bought If the motor is used, in most cases it’s already in the ballpark as far as setup. Turn the main needle valve several clicks rich before starting. Needle Valve Mark the large needle with a spot of paint or etch it with a file or owl. This way you can judge easily how many clicks or turns you make during adjustment. Removing Needle Valves If you have to remove the needle valve to blow out dirt for instance. Count your turns in ¼ or ½ turn increments. This will allow you to replace the needle back to its original setting when maintenance is done. Extra Security for Servo to Receiver Connections Would you like a little extra security to keep servo leads from popping out of the receiver, but hate the mess of glue residue left from tape? Use a hot melt glue gun to lay a bead where your servo connectors come in contact with the receiver. It holds great, but is easy to peel off latter. Dents in Balsa? If you ding your balsa while building, place a few drops of water on the dent and steam out with a covering iron. If the piece is covered (Hanger Rash) use a small diabetic needle to inject a few drops of water under the covering and they use your heating iron. The dent will come right out. Blind Nuts Falling Out? Blind Nuts have a tendency to fall off at the worst time, usually when you can no longer reach the inside of the fuel compartment. Whether building from a kit or assembling an ARF, screwing the bolts for the blind nuts in will keep them from falling out while handling the plane. Re-Seating Blind Nuts If a blind nut does fall out and you can’t reach in to set it in place, try this trick. Using thin coat hanger wire, feed it through the hole and out the radio compartment. Slip the blind nut on the wire followed by a wheel collar. This will allow you to pull the blind nut back in to position. You may need to use a bolt and washer to get it to seat all the way. Pin Inserter Ever get sore fingertips while inserting pins in to your building board. Using a dremal cut off wheel, notch the back of your X-acto knife for T-pins and drill a hole in the center for regular push pins. This will save your finger tips. Vertical Fin Looking for an easy way to hold your vertical fin straight while the glue sets? Wrap a long thin rubber band around the horizontal and vertical stabilizer. Set your vertical stabilizer in position and let the glue set. Tailors Tape The measuring tape that tailors use it great for setting up straight wings and tail surfaces. They are light and can easily have a pin stuck through the tip. Stick a pin through the tape and in the very middle of the front fuselage right behind the firewall. Then measure to the tips of your wings or tail-feathers, when they measure the same on both sides, there straight. There are even tailor tapes that will retract in to a case just like the large measuring tapes used commonly in homes. Fuel Tank Installation After removing your fuel tank for maintenance, it can be a challenge to feed your fuel lines through the fire wall. Feed two flexible nyrods or even thicker coat hanger wires through the front of the fuselage and out the radio compartment. Slip fuel lines over nyrods and pull fuel line through firewall as you insert the tank. Handling Fiberglass Cloth Tame that fiberglass cloth. Hate cutting fiberglass cloth because the ends unravel? Try this next time. Place wax paper down and lay the cloth on top of it. Lightly spray with 3m77 or good old hairspray and then lay another piece of wax paper on top. You can now use a craft knife to cut out strips or what ever shape you want. Remove fiberglass and lay sticky side down where needed. Smooth the wrinkles out and apply CA or epoxy. Removing foam for wheelwells Bend music wire in to the shape of a rectangle of the appropriate size and mount it in to a soldering gun. This makes much cleaner cuts then when digging out with a knife. When making the wire loop, be sure to make it slightly smaller then the size needed. This will compensate for the foam that will shrink away as you cut through. Depth gage for soldering gun foam cutters Keep burning too deep in to your foam wing when cutting wheelwells with your foam cutter? Before mounting the wire loop in to the heat gun, put a wheel collar on each side. You now have an adjustable depth gage that can ride on top of wing skin. Hate Oily Rubber Bands? If you hate the way rubber bands get oily and messy, then you might want to try this. place them in a bag of baby powder or kitty litter. It will suck up the oil and keep your rubber bands from deteriorating. Antenna Tube Ever get frustrated trying to feed your receiver wire down an antenna tube? Spray some WD-40 in to a rage and wipe your antenna first. This should allow it to slide in freely. If not try spraying a little WD-40 down the antenna tube also. Drilling Servo & Control Horns Take a scrap piece of the pushrod the same size your going to use for your project. File down the tip to a chisel like point with a slight angle. These make great drills of the perfect proportion. A dremal with a sanding drum makes quick work of filing the chisel point. Z-Bends Use Z bends at the servo side of the pushrods instead of at the control horn. If for any reason you must remove the pushrod, it is much easier to remove the servo horn and disconnect the pushrod then to unscrew the servo horns from the control surfaces. Perfect Push-Rod Length Thread the push-rod in to the clevis where half of the treads are above and below the main clevis body. Turn your radio on and make sure all radio trims and servo arms are centered. Attach the clevis to the control surface and lay the other side of the control rod across the servo arm hole you are going to use. Mark this with a black felt tip, remove control rod, and make your Z-bend using the previous mark you just made. Reinstall your push-rod and make adjustments as needed with clevis. 2-56 & 4-40 Die An inexpensive die handle and die for 2-56 or 4-40 size pushrods (or what ever sizes you use the most) is a great time saver for those who use Z bends. If you’ve ever made a Z bend and found the pushrod to be to long for instance, you can cut longer running threads and then snip the pushrod to the appropriate length. More Die Tips Ever buy 12 inch pushrods for your wing setup? You can buy pushrods that are 36 inches long for about 7 cents more. With a die you can make 2 to 3 pushrods or any custom odd size (like throttle) you need from the scrap rod left over. Another Die Tip Would you like to use a clevis on both sides of your pushrods? With a die it make the task easy. No more soldering threaded clevises on to steel rod or having to buy expensive nylon pushrods to accomplish the same result, use inexpensive steel rod. Work Table Looking for a inexpensive work table? Discarded or blemished hollow core doors are inexpensive or even free. They make great building tables. Simple 2 x 4s can be used to make a bottom frame support and legs. Using the hinges to attach it to a basement or garage wall will allow you to raise or lower it out of the way when not in use. Covering Table Another use for hollow core doors. With the home renovation craze, hollow core doors can be found for free. If the door isn’t perfectly straight though, you could end up with built in warps in your bird. Don’t throw it out though. Cover the door with a couple of old blankets (a few dollars form garage sale) and you now have a great covering table that won’t scratch or dent your plane as easy. Fold the blanket over the sides and under the tables edge. Secure it with upholstery tacks or nails. Makeshift Washer In a pinch for a washer or motor mount shim? 5 cent pieces with the right size hole drilled in them, make fabulous makeshift washers. Workshop Cart Bolt an old drawer to the top of a used TV cart (from garage sale or thrift shop) with casters. It makes a wonderful shop cart to hold tools or other odds and ends which can now be easily moved from one side of the shop to the other. Nut and Bolt Identifier Identify bolts and nuts easily. Most modelers will end up with a bowl of various size nuts and screws. Use an old cutting board made of polycarbonate or buy a small one form Wal-mart for just a few dollars. drill a row of holes (slightly smaller then the size screws you use) and use the screws themselves to tape threads in to the board. Label each tread size e.g. 2-56, 4-40, 6-32, 2mil, 3mil ect. Now drill another set of set of holes just below the first and glue the corresponding bolts thread side out. You can now use the threaded holes to identify bolts and the threaded bolt to identify nuts quickly. Magnetic Parts Tray Take an old metal pie pan and place magnets on the bottom. Strong magnets can be found in old speakers that you see being discarded. While building or disassembling for repairs and maintenance. Place screws, nuts and bolts in pan for easy sorting. |
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