Gears, Chains, and Sprockets - VEX Robotics

More documents

Recommendations

Info

Engineering NotebookCreate the following blank chart in your engineering notebook:Drive Gear Driven Gear ReductionRatioPulley FreeSpeed (RPM)CalculatedMotorTorqueTime to lift24"12 8412 6036 8436 6060 84■■■■Using the knowledge you gained on gearing, speed, power, and torque in the previous ThinkPhases, complete your chart appropriately. Remember the following:Reduction Ratio = # teeth of drive gear / # teeth of driven gear.Free Speed = Motor Free Speed x Reduction Ratio. Go back to your notes from the Unit 5: Gears,Chains, and Sprocket > Amaze Phase, where you calculated the free speed of a VEX motor.Motor Torque = Mass x Pulley Radius x Reduction Ratio.Create a graph showing the relationship between the Reduction Ratio and Time to Lift the mass.In your notebook, discuss the shape of your graph. Does it surprise you?How can you lift the mass even faster using this test stand? How would it need to be modified?Discuss what changes you would make to accomplish this task. If time remains, execute your plan.PresentationPrepare your findings from this phase, and present them to the class. Explain why you and yourclassmates may not all have the same results. Discuss how you can modify the test stand to lift theweight even faster.58■Unit 6: Gears, Chains, and Sprockets
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
Page 3 and 4:
SuppliesSoftwareAn assembled the ge
Page 5 and 6:
PhaseBuildStandardScience (NSES)Uni
Page 7 and 8: Think PhaseOverviewThis phase expla
Page 9 and 10: Spur GearsSpur gears have been used
Page 11 and 12: The driving torque applies some for
Page 13 and 14: Idler GearsGears can be inserted be
Page 15 and 16: Compound Gear RatioCompound gears a
Page 17 and 18: Chain DrivesSprockets and chains ar
Page 19 and 20: Create PhaseOverviewThis phase desc
Page 21 and 22: Icon Name DescriptionRectangularPat
Page 23 and 24: Example: Generated GearsIn the foll
Page 25 and 26: Enter data to design the gear set.I
Page 27 and 28: Exercise: Generate Spur GearsIn thi
Page 29 and 30: 12. To check your design again, cli
Page 31 and 32: 9. Press E to start the Extrude too
Page 33 and 34: 4. For Operation, select Cut.2. Exp
Page 35 and 36: 14. Click OK.3. Click again to crea
Page 37 and 38: Extrude the Sketch on the Back Face
Page 39 and 40: 7. For Count, enter 5.8. For Spacin
Page 41 and 42: Insert an iFeatureIn this section o
Page 43 and 44: Exercise: Animate a Gear AssemblyIn
Page 45 and 46: 9. Scroll back to SHAFT-3000:5. Rig
Page 47 and 48: Required Supplies and SoftwareThe f
Page 49 and 50: 2. To complete the next step:■■
Page 51 and 52: 4. To complete the next step:■■
Page 53 and 54: Amaze PhaseOverviewIn this phase, y
Page 55 and 56: f. Set up the test stand between tw
Page 57: Figure 4: 36:60 ReductionFigure 5:
show all

Gears, Chains, and Sprockets - VEX Robotics

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?