Gears, Chains, and Sprockets - VEX Robotics

STEM ConnectionsBackgroundThe United States Coast Guard often uses rescue helicopters when responding to maritimeemergencies. These helicopters can assist in rescue efforts by hovering above their target andinserting a rescue swimmer whose job it is to reach the survivor and stay with them until bothswimmers can be extracted via a rescue line from the helicopter. The helicopter extraction isaccomplished with a winch system similar to the VEX Test Stand you use for this unit.ScienceCoast Guard rescue helicopters often operate in extreme conditions. As a result, the winch systemsinvolved in ocean rescue must be able to withstand the harsh ocean environment.1. What are some of the material science transformation processes (for example, corrosion) that youneed to consider when designing a winch for this sort of application?2. What associated problems can occur if the winch system is not designed to resist these harshconditions?3. What materials can you use to build a weather resistant winch system, and how do those materialsaffect the operation of the winch?4. Design a laboratory test to determine which materials are the best choice for these conditions.TechnologyConsider that the helicopter’s winch system may be subject to very different loads, given differentrescue circumstances. For instance, the weight of the survivors, the number of survivors, and theweather and water conditions can all affect the load.1. How would a system that switches gear ratios based on the potential load improve the efficiencyof the rescue winch system?2. How can this be accomplished?STEM Connections■59