Cables Flashcards
Control cables
Quadrant
Cables
Cable end fittings
Tension regulator
Turnbuckles
Pulleys
Fairleads
Control quadrant
Changes a control rod run to a cable or a cable to a control rod run.
Bearing in the middle acts as a pivot point.
Cable swaged end fittings mounted in receptacles in the quadrant.
Cable sits in a grooved permimeter.
Control rod attaches at the edges of the quadrant.
Cables
Strong, light and flexible.
They operate in tension so can only be used as a pull control.
Two cables can be arranged in a continuous loop to provide a pull in both directions.
The rear quadrant pushes the control rod into the servo.
Cables and quadrants
We go from a quadrants back to a rod to operate the servo
Control cables new terminology
Preformed cable.
Swaged end.
Lock clad cable.
Nylon coated cable.
Thermal expansion.
Tension regulator.
Preformed cable.
A process in which each individual strand is formed into the shape it will take in the completed cable.
More flexible.
More resistant to kinking.
Will not unravel; if a wire breaks, it will lie flat.
Less likely to prevent the cable from passing round pulleys through fairleads.
Cable end fittings.
Preformed cable is manufactured from corrosion resistant steel.
Various fittings swaged on to the end of the cable during manufacturing.
Swaging is when the cable end is inserted in to the hollow end fitting and then the shaft of the end fitting is squeezed on to the cable end.
Lock clad cable.
Standard, flexible steel wire cable with a length of tubing swaged to it.
Locks the cable and tube together so considerably reduces changed in tension due to temperature variations.
Reduced cable stretch under load.
Whipping action is reduced in long runs as the cable is now relatively rigid.
Nylon coated cable.
Flexible nylon sleeve extruded over corrosion resistant cable.
Nylon protects from ingress of debris and reduces wear.
Reduces friction between cable and pulley. This reduces the overall friction on the control system.
Thermal expansion of control cables.
Aluminium alloy has a higher coefficient of expansion than steel.
With increasing ambient temperature the fuselage will expand more than the cables.
Tension of cables will increase.
If temperature decreases, cables will become slack.
Overcome this by a tension regulator.
Tension regulator.
Simple spring loaded device.
Need for cable tension.
Keeps the tension in limits.
Excessive tension = controls hard to move.
Not enough tension = ineffective response in controls.
Cable systems are pre tensioned IAW maintenance manual.
Must check cables at regular intervals
