subject: Controls And Construction Of Rc Helicopters [print this page] Rc helicopters normally have more than four controls which include the rudder (yaw, pitch/throttle (collective pitch/power), elevator, and Cyclic pitch. For simple rc choppers flight, the radio is normally configured in such a manner that the pitch sound is about 1-degree at 0% throttle stick and about 10 degrees at 100% throttle stick. The modulation of the throttle in conjunction with the pitch maintains a constant high speed. The benefit of this is consistency and smoothness of flight performance. For an aerobatic 3D performance, the idle up mode of flight is used. This mode allows for collective pitch ranges from the negative limit of 0% throttle stick input to the positive limit of 100% throttle stick.
The modulation of the throttle on the other hand is dome automatically using radio transmitter for maintenance of constant head speed and is at lowest value when the throttle stick is centered and the pitch set at zero. The motor produces an upward thrust at this mode using negative pitch of which when inverted allows for the sustenance of inverted flight. A more advanced computer radio is applicable for this type of flying that allows customization of throttle-collective mix. The yaw and cyclic controls are not different by definition in the two modes but 3D rc helicopters pilots can configure their models to be more responsive.
The constructions of remote controlled helicopters are normally made of plastic, aluminum, glass-reinforced plastic or carbon fiber. The Rotor blades are normally made of fiberglass, wood or carbon fiber. The purchase of rc helicopters models is done in kit form from a unit of about a dozen manufacturers. The remote controlled helicopters units take about 5 to 20 hours to assemble them completely. The model remote controlled helicopters are made of many moving parts analogous to those of full-size helicopters beginning from the swash plate to the rotor and all else in between. The building of rc helicopters has be more accurate than for fixed wing model airplanes because of helicopters being prone to even the smallest of vibrations that cause problems when not in flight. The rc choppers and their components are small in size and low in weight specifically cyclic that have a very fast response to cause rotation rates much faster compared to the equal input on full-size aircraft.
There are some situations whereby the quick response cause the model aircraft unnecessary difficult to fly. It is for this reason that many model helicopters dont use the Bell rotor head design but instead use the Hiller design that has a Flybar or a Bell-Hillar mixing. Flybar offers a much greater degree of stability while Bell Hiller mixes the quick response of the Bell system with stability of Hiller design. Some models make use of the simple bell design but limited to scale models challenging to fly or models that make use of advanced electronic stabilizer equipment. For purposes of reducing mechanical complexity and increase the precision of control for the swashplate, some model rc helicopters use collective/cyclic pitch mixing.
