Measure the force required to operate the object to be controlled (valve, throttle, PTO, etc).

Using the following formulae, approximate the required input load.

• if = of x tdb x ff + of
  
• if = input force refers to the operator end of the cable
  
• of = output force (newton or Pound)
  
• tdb = total degrees of bend (e.g. 1800 + 900 +900 = 360)
  
• ff = FRICTION FACTOR (see table below)

Where operating levers used to determine the required travel including an allowance for backlash, then select an appropriate series of cable that matches the required load and travel. NOTE: Load capacities relative to travel for push loads.

The output motion of the workend of the cable is essentially the same as the input motion.

For example, a 75mm(3") pushing movement at the input end will result in a 75mm(3") pushing movement (less backlash) at the output end. If a differential between input and output, and/or direction of movement is desired, it must be accommodated in the design of the lever attachment point at the workend.

For the best efficiency and longest operating life, install the cables so that it encounters the heaviest load in the "Pull" mode of operation (see Figure 2).

Travel = 2 (sin θ) (Lever Length) (see Figure 1)