If you have questions about aircraft cable system designs involving pulleys, or any other technical aspects of cable systems, please contact a or contact a product manager for more information. We would also recommend more frequent inspections to check for signs of fatigue. The regulator 10 is also used to control tension in cables 12, 14. 1 and 2, a cable tension regulator of the present invention generally indicated at 10 is capable of receiving an input force and transmitting an output force for use in mechanical control of flight controls of an aircraft. In this case be aware that if your system is designed with a lower D:d ratio, as we stated above, you can expect fatigue and failure sooner than if you used a larger pulley or smaller aircraft cable. Referring now to the drawings, and first to FIGS.
We understand that in many applications device size and space restrict the size of pulley you can use. We recommend minimum D/d ratios (see the general design guidelines below and on our website) to assist in your design.
Keep in mind that there are many other forces at play in an aircraft cable and pulley system that can affect fatigue and failure, so testing of your design is a must to determine how all the forces affect fatigue and cable longevity.
For example, if a designer chooses to select different operating parameters, such as a smaller pulley, we would expect relative service life reductions. This means that the resulting design guidelines do not provide absolute service life figures, but a gauge of service life relative to other design choices. It’s a method of understanding the relative service life of a cable on a particular diameter pulley when compared with other available diameters. What does the D:d ratio mean? As a general rule, the larger the D:d ratio, the longer the wire rope service life. So, the larger the pulley that you design for use with a given cable size, the higher the D:d ratio. What is the D:d ratio? The D:d ratio is a guideline established to assist in maximizing cable life & prevent accelerated failures. The D stands for the diameter of the pulley being used, while the d stands for the diameter of the cable (overall diameter on jacketed aircraft cable). When designing systems that will use aircraft cables over pulleys, you lessen fatigue and extend service life by choosing the highest possible D:d ratio for yourapplication. This applies especially in critical applications, such as aircraft flight controls, lifting and hoisting systems, and exercise equipment, where unnecessary fatigue and premature failure could result in damage to property, or worse. New Trim Tab Actuator and Repair Services also available.While the working of an entire aircraft cable system involves much more than simply picking the proper pulley, understanding aircraft cable performance and longevity in relation to pulley size is very important. If you can't find the cable you are looking for, McFarlane offers Custom Cable Fabrication services.įor more information, go to McFarlane Flight Control System Features. Don't forget to replace your trim control chains! McFarlane offers the trim control chains for Cessna single engine and most Beechcraft aircraft.
#CABLE AND PULLEY FLIGHT CONTROL SYSTEM HOW TO#
Cables available in galvanized or stainless steel - How to Determine Flight Cable Composition.McFarlane also stocks cables for single engine piston and many turbine and twin engine Beechcraft, and stabilator adjust cables for Piper J3, PA11, PA12, PA14, PA16, PA18, PA18A, PA20 and PA22 aircraft. We have FAA-PMA approved cables available in corrosion resistant stainless or high strength galvanized steel for most 100 and 200 series Cessna aircraft, PA28, PA32, and PA34 series Piper aircraft and G-164 series Ag-Cat aircraft. McFarlane has over 4,500 cable assemblies and chains in stock.