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RC Engines for Model AirplanesRC engines provide the thrust for pulling our birds through the air. When I first became interested in flying RC airplanes, I thought that all model airplane engines were "gas" engines. This is a common misconception because many companies market glow engines as "gas" engines because they assume a beginner doesn't know the difference. The vast majority of model airplane engines are glow engines, commonly referred to as nitro RC engines, because they are cheaper and easier to use than gasonline engines. Glow engines use glow plugs initiate combustion (not spark plugs) and they burn nitro-methane fuel. Both 2-stroke and 4-stroke nitro RC engines are available. You can find a a more in depth discussion of 2-stroke vs 4-stroke RC engines here. Larger RC airplanes can be flow with an actual gasoline engine. True gas RC engines have a lower power to weight ratio, require an ignition system to power the spark plug, and are generally more difficult to operate compared with a nitro RC engines. Obviously it takes more power to pull a larger airplane. There comes a point, generally around 10lbs, where it becomes more economical to use a gasoline engine due to the price difference between nitro fuel and gasoline. Sizing the PropellerSizing the propeller for your airplane is just as important as choosing the correct size engine. The propeller is what converts the power that is produced by the engine into thrust that is needed to fly the airplane. With a vehicle, the transmission converts the engine power into torque that turn the wheels to propel the car forward. With an airplane the propeller is the transmission.The transmission of a car gives the driver a range of gears to choose from depending on whether he wants speed or torque. If the driver is taking off from a stoplight he starts with first gear because more torque is needed to get the car moving. As the speed increases, the car gains momentum and needs less torque to continue at the current speed. Each time the driver shifts to a higher gear the transmission produces more speed and less torque for a given engine RPM.
Sizing a propeller is exactly the same as choosing the right gear when driving your car. With a model airplane you can only "change gears" in between flights by changing the propeller. This means you must find a happy medium between speed and thrust when choosing the propeller. Just like a gear, a propeller sized for very high speed will not be very good for taking off. A propeller sized for extreme thrust for “unlimited” vertical climb would not be able to pull the airplane through the air very fast. So it is a trial and error process to find the propeller that is just right for you and your airplane! Follow for more information on how to choose the right propeller. Spinners The spinner is the nose cone of the airplane. The spinner increases the efficiency of the propeller. The base of the propeller blades are very blunt and do not push any air. The spinner diverts air around this portion of the blades to the portion of the blades that actually moves the air. Full-scale airplanes have spinners for this reason.
Spinners also provide a place for the electric starter to grip when turning the engine over. If you live in the United States you should know that the AMA requires that every nitro-powered airplane have either a spinner or AMA safety nut such as the one to the left. Engine InstallationAfter much research you have finally purchased the perfect RC engine for your new airplane. Installing the engine is one of the most exiting parts of putting an airplane together.This is one of the last steps before you can enjoy all of the hard work and time you’ve spent getting your bird ready for the sky! Please don’t rush the engine installation. Installing the engine is not difficult, but it is very important that everything is done properly. The alignment of the engine is critical. If the engine is installed crooked, the thrust from the engine will be applied crooked! This could leak to some awful flight characteristics and in extreme cases could make the airplane completely uncontrollable. If you take your time and follow the directions to a “T” you and make sure everything is good and tight you will have nothing to worry about. Installing the RC engine entails more than just bolting the engine to the firewall. The fuel tank must be installed with the fuel lines ran correctly from the engine’s carburetor and exhaust to the correct ports in the fuel tank. It is necessary to connect the control linkage from the throttle servo horn to the carburetor arm in a way that it is not in binding and is the correct length. If your airplane has an engine cowling it will be necessary to mount the engine sideways or inverted. You will also have to trim the cowling to fit your engine. The cowling must be positioned properly to prevent the engine’s back plate from rubbing it. It also may be necessary to install an exhaust deflector to route the exhaust out of the cowling. For a more in depth look at installing RC engines, fuel tanks, and control linkages feel free to take a look here.
Learning to Fly - Choosing First Plane - Flight Sims - Field Equipment
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