Softstopper

Softstopper is a term used in engineering and design to describe a mechanism, feature, or control approach that ensures a system comes to rest or reduces motion smoothly, minimizing mechanical shock and wear.

In mechanical systems, a soft stopper commonly uses compliant elements such as elastomer pads, springs, or hydraulic or pneumatic cushions placed at the travel limit. When a moving component reaches the limit, energy is absorbed gradually, preventing hard contact, reducing noise, and extending actuator life. Soft stoppers are used in robotic arms, CNC machines, automotive closures, and consumer devices where repeated contacting limits occur.

In control and software contexts, a soft stop describes strategies that taper velocity or halt activity with a ramp rather than an abrupt shutdown. Techniques include ramp-down curves, motion profiling, rate limiting, and soft-start/soft-stop algorithms that reduce shocks, power spikes, and system overshoot.

The term is not universally standardized and overlaps with related concepts such as bump stops, soft landings, or soft-start, with definitions varying by industry and application. Some sources distinguish between purely mechanical cushions and control-based deceleration, depending on whether the emphasis is physical energy absorption or gradual cessation of motion.

Overall, softstoppers share a common goal: limit motion or cessation in a way that protects components, reduces wear, and promotes smoother, more predictable operation.