The Importance of Fly LinesWritten by Brett Fogle
Why are fly lines so important? Just like with fly rods and fly reels, fly lines need to match up with types of fly fishing that you do. This match should be made precisely, too. Thus, if you have a 5 weight fly rod and a 5 weight fly reel, and it extremely important to make sure you have a 5 weight fly line. By not having a properly "balanced" fly rod outfit (which is where fly rod, fly reel and fly line match in weight), angler is very likely to have extreme difficulty in casting.For example, using too light of a fly line for a particular fly rod will present severe casting challenges. Remember, in fly fishing, weight of fly line - not fly itself - is what allows angler to cast. The fly rod, as it is essential to casting, will not properly cast wrong weight fly line. Thus, where fly rod is "heavier" than fly line, fly rod will never be fully loaded (will not bend properly), since weight of fly line is not enough to properly bend rod during cast. Likewise, should fly line be heavier than fly rod, fly rod will bend excessively during cast, making line control an iffy proposition at best. In essence, if you forget everything you just read on fly lines, please try to remember this very simple thing. Make sure your fly line weight matches precisely weight of fly rod you are using as well as weight of fly reel you are using. In an ideal world, you want to always go by this formula : Fly Line Weight = Fly Rod Weight = Fly Reel Weight
| | The Two-Stroke Model Airplane EngineWritten by Andre McFayden
The two-stroke model airplane engine is a simple and elegant concept. The majority of these are not gasoline, but “glow” or “nitro” engines. These names are due to fuel and combustion methods. The fuel itself contains methanol, nitro methane and oil. The combustion is due to a plug that glows instead of sparking (as in other common two-stroke engines). While there are many variations on design, basic elements remain unchanged. There is a piston moving back and forth in a cylinder. The piston is connected by a hinged rod to a rotating crankshaft. There is a combustion event on every other stroke of piston (at beginning of down-stroke). The combustion is caused by a platinum element in a heated glow plug, combined with a compressed fuel-air (and oil) mixture. There are also intake, exhaust and transfer ports, to move around fresh and used fuel. A carburetor is used to mix air with fuel in required ratio for power output needed. The piston itself functions as a fuel-air-exhaust valve, eliminating need for extra parts found in four stroke engine. The engine is also its own fuel pump, as movement of piston pressurizes crankcase. The fuel carries its own oil, further simplifying design. And last but not least, being able to remove battery after engine starts, due to self-sustaining glow-plug, reduces weight considerably. This is very desirable in a model airplane engine.
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