Tuesday, March 6, 2018
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Wednesday, January 17, 2018
Saturday, January 13, 2018
Sunday, December 17, 2017
The FAI CIAM Aeromodelling Commission is pleased to announce that
The 2018 FAI F2 World Championships for Control Line Model Aircraft (Seniors & Juniors)
will be held in Landres - France, from the 14th (open Ceremony) to the 19th (Closing Ceremony) of July 2018.
פורסם על ידי dvir ב- 6:36 AM
Sunday, November 26, 2017
The aircraft is typically controlled by a set of 20–70-foot lines usually of multi strand stainless steel, single strands of piano wire, or G.S.U.M.P. (Gel Spun Ultra-high-molecular-weight polyethylene, made by DuPont). For sport flying, non-metallic lines of kevlar, dacron, or other low-stretch fiber materials are commonly used. This type of control was originally trademarked as "U-Control" and is by far the most common control method.
The controls of a conventional 2-line/"U-Control" system consist of lead-out cables, a bellcrank, push rods and control horns. These are connected so that differential motion of the lines rotates the bellcrank, causing a pushrod to move either forward or aft. The pushrod is connected to the control surface with a control horn that moves the elevator (and flaps, if used) up and down. The pilot holds a handle to which the lines are attached. Tilting the handle with the fingers, wrist, and/or elbow motion causes the differential movement in the lines. By convention, tilting the hand so the top is closer to the pilot than the bottom results in "up" elevator, much like pulling back on a full-scale airplane control stick. Also by convention, most airplanes are flown nominally counter-clockwise as viewed from above, with the leadout cables exiting the left wing. This is not universal and some pilots fly in the opposite direction. Flying clockwise has a slight advantage in some situations because most engines run so that the torque will roll the airplane away from the pilot, increasing line tension in upright level flight.
The controls can be expanded by adding a third line that controls the throttle. The most common system for throttle control is that devised by J. Robert Smurthwait, of Baker Oregon, and is widely available. The throttle is usually a conventional carburetor as used on radio control models schemes that couple limited rudder and/or aileron, and variable leadout position are often found on carrier planes as well as elevator and flaps/ Monoline control works by twisting the single line. The pilot holds a handle with a twisted flat piece of metal on bearings in one hand, and a "bobbin" in the other. Moving bobbin towards or away from the handle twists the line. Inside the airplane, the rotating line rotates a spiral scroll with a follower. The follower moves toward and away from the pivot of the scroll, and has a pushrod attached. Then, as the scroll rotates, the pushrod moves fore and aft. The rest of the system is like the two-line system. The control of a monoline system is much less precise than a two-line system because the line itself tends to twist up before it moves the scroll, leading to a somewhat vague control response with considerable lag. It does however have the advantage of not requiring as much line tension to move the controls, and the single line has less drag than the two slightly smaller lines used in conventional two-line control.
Wednesday, November 22, 2017
Models on lines and flying in circles predate manned flight. Early versions merely constrained the model to fly in a circle but offered no control. This is known as Round-the-pole flying. The origins of control-line flight are obscure but the first person to use a recognizably modern system is generally considered to be Oba St. Clair, in June 1936, near Gresham, Oregon.St. Clair's system used a rather large apparatus similar to a television antenna, onto which many lines were attached. This system is very different from those currently in use on modern control line models.
The name most associated with the promotion of control line, and the inventor of the formerly patented system known as "U-Control" (which was a trademark, and is the system in use on virtually every two-line control line model today) was Nevilles E. " Jim" Walker. His "American Junior" company was by far the biggest producer of models, and held numerous patents on the two-line system until overturned during a patent infringement suit, by Walker, against Leroy M Cox, based on "prior art" from St. Clair in the 1955 trial. One of the most coveted prizes in control-line aerobatics competition sanctioned by the AMA, awarded to the winner of a flyoff between the US Junior, Senior, and Open age class Champions, was originally provided by and is named for Walker. This is one of the oldest perpetual trophies in modeling that is still awarded.