Considering Design Factors of Lost Motion
Synopsis:
Mechanical control cables provide a simple, lightweight, economical, and reliable way to activate throttles, latches, gas springs, electromechanical devices, and many other mechanisms.
The basic design of mechanical control cables features a movable core that’s free to travel axially inside a conduit. Actuating a lever or similar device at one end of the cable assembly produces output force and motion at the other end.
In this white paper, the design factors of load, travel, lost motion, backlash, and deflection and the friction factor affecting efficiency are discussed and mathematical calculations are presented for consideration.
What is Lost Motion?
Perhaps the least-understood design factor is lost motion. All push-pull controls lose some motion between input and output sides when applying a load to the system. Lost motion increases with higher loads, more bends, and longer assembly lengths. It can be overcome by designing overtravel into the system at the input or output ends, or at both ends.
Designing Control Cables to Account for Lost Motion
Because backlash, deflection, and friction are critical factors to consider when designing mechanical control cables, engineers should consider the parameters of:
- Load
- Routing
- Friction
- Stretch
- Permanent set
- Lost motion
- Temperature
- Environment
- Exposure to contaminants
Download now to read the full white paper!
