Tag Archives: tail

Radio Controlled Helicopters

Radio controlled helicopters (also RC helicopters) are model aircraft which are distinct from RC airplanes because of the differences in construction, aerodynamics, and flight training. Several basic designs of RC helicopters exist, of which some (such as those with collective pitch, meaning blades which rotate on their longitudinal axis to vary or reverse lift) are more maneuverable than others. The more maneuverable designs are often harder to fly, but benefit from greater aerobatic capabilities. Flight controls allow pilots to control the collective and throttle (usually linked together), the cyclic controls (pitch and roll), and the tail rotor (yaw). Controlling these in unison enables the helicopter to perform most of the same maneuvres as full sized helicopters, such as hovering and backwards flight, and many that full sized helicopters cannot.

The various helicopter controls are effected by means of small servo motors, commonly known as servos. A piezoelectric gyroscope is typically used on the tail rotor (yaw) control to counter wind and torque reaction induced tail movement. This gyro does not itself apply a mechanical force, but electronically adjusts the control signal to the tail rotor servo. The engines typically used to be methanol powered two stroke motors, but electric brushless motors combined with a high performance lithium polymer battery (or lipo) are now more common and provide improved efficiency, performance and lifespan compared to brushed motors, while decreasing prices bring them within reach of hobbyists. Gasoline and jet turbine engines are also used.

Common power sources are nitro (nitromethane methanol internal combustion), electric batteries, gas turbines, petrol and gasoline. Mechanical layouts include cyclic/collective pitch mixing (CCPM) in all power sources, fixed pitch electric rotors and coaxial electric rotors. Practical electric helicopters are a recent development but have rapidly developed and become more common, overtaking nitro helicopters in common use. Gas turbine helicopters are also increasing in popularity, although the high cost puts them out of reach of most people.

Nitro or glow fuel helicopters come in different sizes: 15, 30, 50, 60 and 90 size. These numbers originated from the size of engine used in the different models (0.30 cu in, 0.50 cu in and so on). The bigger and more powerful the engine, the larger the main rotor blade that it can turn and hence the bigger the aircraft overall. Typical flight times for nitro helicopters is 7-14 minutes depending on the engine size and tuning. The maximum height of operation for RC helicopters, be it nitro or electric, is only limited to the height at which the controller can see the model. Most radio systems have a range of over a mile, and the person controlling the model will have long lost sight of the model.

Two small electric helicopters emerged in the mid 1990s. These were the Kalt Whisper and the Kyosho EP Concept, flying on 7/8 1200 mah NiCad batteries with brushed motors. However, the 540 brushed sized motors were on the limit of current draw, often 20-25 amps on the `hotter’ motors, hence brush and commutator problems were common. S107 metal series Recent advancements in battery technology are making electric flying more feasible in terms of flying time. Lithium polymer (LiPo) batteries are able to provide the high current required for high performance aerobatics while still remaining very light. Typical flight times are 4-12 minutes depending on the flying style and battery capacity.

Small fixed pitch helicopters need a 4-channel radio (throttle, elevator, aileron, rudder), although micro helicopters that utilize a 2-channel infrared control system also exist; while collective pitch models need a minimum of 5 channels with 6 being most common (throttle, collective pitch, elevator, aileron, rudder and gyro gain). Because of the normal interaction of the various control mechanisms, advanced radios include adjustable mixing functions, such as throttle/collective and throttle/rudder. RC Helicopters usually have at least four controls: Roll Cyclic Pitch, Elevator (Fore Aft Cyclic Pitch), Rudder (Yaw) and Pitch/Throttle (Collective Pitch/Power).

Radio Controlled Helicopters

Radio controlled helicopters (also RC helicopters) are model aircraft which are distinct from RC airplanes because of the differences in construction, aerodynamics, and flight training. Several basic designs of RC helicopters exist, of which some (such as those with collective pitch, meaning blades which rotate on their longitudinal axis to vary or reverse lift) are more maneuverable than others. The more maneuverable designs are often harder to fly, but benefit from greater aerobatic capabilities. Flight controls allow pilots to control the collective and throttle (usually linked together), the cyclic controls (pitch and roll), and the tail rotor (yaw). Controlling these in unison enables the helicopter to perform most of the same maneuvres as full sized helicopters, such as hovering and backwards flight, and many that full sized helicopters cannot.

The various helicopter controls are effected by means of small servo motors, commonly known as servos. A piezoelectric gyroscope is typically used on the tail rotor (yaw) control to counter wind and torque reaction induced tail movement. This gyro does not itself apply a mechanical force, but electronically adjusts the control signal to the tail rotor servo. The engines typically used to be methanol powered two stroke motors, but electric brushless motors combined with a high performance lithium polymer battery (or lipo) are now more common and provide improved efficiency, performance and lifespan compared to brushed motors, while decreasing prices bring them within reach of hobbyists. Gasoline and jet turbine engines are also used.

Common power sources are nitro (nitromethane methanol internal combustion), electric batteries, gas turbines, petrol and gasoline. Mechanical layouts include cyclic/collective pitch mixing (CCPM) in all power sources, fixed pitch electric rotors and coaxial electric rotors. Practical electric helicopters are a recent development but have rapidly developed and become more common, overtaking nitro helicopters in common use. Gas turbine helicopters are also increasing in popularity, although the high cost puts them out of reach of most people.

Nitro or glow fuel helicopters come in different sizes: 15, 30, 50, 60 and 90 size. These numbers originated from the size of engine used in the different models (0.30 cu in, 0.50 cu in and so on). The bigger and more powerful the engine, the larger the main rotor blade that it can turn and hence the bigger the aircraft overall. Typical flight times for nitro helicopters is 7-14 minutes depending on the engine size and tuning. The maximum height of operation for RC helicopters, be it nitro or electric, is only limited to the height at which the controller can see the model. Most radio systems have a range of over a mile, and the person controlling the model will have long lost sight of the model.

Two small electric helicopters emerged in the mid 1990s. These were the Kalt Whisper and the Kyosho EP Concept, flying on 7/8 1200 mah NiCad batteries with brushed motors. However, the 540 brushed sized motors were on the limit of current draw, often 20-25 amps on the `hotter’ motors, hence brush and commutator problems were common. S107 metal series Recent advancements in battery technology are making electric flying more feasible in terms of flying time. Lithium polymer (LiPo) batteries are able to provide the high current required for high performance aerobatics while still remaining very light. Typical flight times are 4-12 minutes depending on the flying style and battery capacity.

Small fixed pitch helicopters need a 4-channel radio (throttle, elevator, aileron, rudder), although micro helicopters that utilize a 2-channel infrared control system also exist; while collective pitch models need a minimum of 5 channels with 6 being most common (throttle, collective pitch, elevator, aileron, rudder and gyro gain). Because of the normal interaction of the various control mechanisms, advanced radios include adjustable mixing functions, such as throttle/collective and throttle/rudder. RC Helicopters usually have at least four controls: Roll Cyclic Pitch, Elevator (Fore Aft Cyclic Pitch), Rudder (Yaw) and Pitch/Throttle (Collective Pitch/Power).

Search Engine Optimization – SEO

Any Internet marketer who has been in the business for some time has probably heard the term “SEO” a thousand times by now. Internet marketing newbie’s should expect to hear it a lot as well because it will play a huge role and determine the success of their online career.

SEO stands for search engine optimization. This term basically refers to the use of keyword phrases to get a high page rank in the Google search engine. For online marketers, the process begins by picking out a few keyword phrases related to your niche. For instance, if you are promoting a weight loss product on your website, then you might pick out a long tail keyword like “how to lose weight fast” or “how to lose weight naturally”. You want to use keywords that web surfers will likely enter when searching for information about your niche.

The next step is to use a service tool like the Google Keyword Tool Bar. This tool will let you know how often a keyword phrase is searched. It will also give you an estimate of how competitive a keyword phrase is. Remember that other Internet marketers will be vying for the same keywords as well. Ideally, you want to use keyword phrases that get decent searches but are not too competitive. You should stick to long tail keywords about three to six words long. Going back to the previous example, a broad term like “lose weight” or “weight loss” may get a lot of searches, but it is also much more competitive. You will be more likely to make it to the first page of Google with long tail keywords.

Once you have your keywords picked out, include them in your website. They should appear several times in the text and in the title. Include it in the URL if possible. You also want to visit blogs and forums within your niche and include a link back to your website with the keywords as the anchor text. Article directories are another good place to drop off a link. Just write an article related to your niche and include a link in the resource box. This process is known as link building. Link Building takes time and involves tedious work. However, this technique will slowly improve your page rank.