How to Tune Your Model Airplane EngineWritten by Andre McFayden
Tuning is simply adjusting your engine for peak performance. The factory-fresh settings may be a good starting point. However, you may need to compensate for higher altitudes, or for temperature changes with seasons. Changes in fuel type or engine wear, may also require a tune-up. Relatively more fuel to air is known as a "rich" mixture, while opposite is known as a "lean" mixture. A lean mixture generates more power, but also generates more heat. Too much heat could damage engine. A rich mixture generates less power and less heat. Too rich and engine might quit while you're flying. The popular twin-needle carburetor has two needle valves. The high speed needle controls total fuel flow into engine, and affects engine's behavior from half to full throttle. The low speed needle tends to have more of an effect from half throttle down to idle. Both low and high speed needles can be richened (counterclockwise turning), or leaned (clockwise turning). Tuning Procedure: 1) Start with factory recommended needle valve settings. 2) Start engine. 3) With engine or aircraft secured, open throttle to full. 4) Lean high speed needle slowly and watch and listen: Too rich: lots of smoke, low pitched sound Leaner: reduced smoke, sound starts changing to higher pitch Leaner still: little smoke, max rpm reached Too lean: very little smoke, max rpm can be heard falling off. Open needle valve up 20 or 30 degrees from this point. If you have a tachometer, open needle about 300 rpm less than max.
| | The powers of the mother of pearlWritten by Jakob Jelling
Oriental and Chinese cultures as well as many occidental ones follow traditions based on belief that some precious stones have important symbolisms and powers. The mother of pearl is one of them, and it is often used for feng shui practitioners in order to attract a benefit towards a strategic house point or to improve a specific life area.Some stones are believed to have power of attracting happiness or love to life of whom carries them or keep them in their homes. The way in which a stone is seen and what it symbolizes depends not only on its type but also on way it is used and seen by each specific culture and traditions behind it. Usually, in many occidental cultures symbolism of a stone is followed by wearing it as a ornament and jewelry, while in many oriental cultures and mainly Chinese one, these stones are often used in symbolic objects which are strategically placed in house. This way, stones depend on way they are used and to which kind of object they are added to in order to have their meaning and to attract specific benefits.
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