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Team 10. Team Members: Warren Chan Alicia Powers Thomas Velky. An Overview. Spring loaded ramps simply transport 'junk mail' to bottom holes Adversaries are thwarted by a comprehensive blocking scheme. Design Process. Initial premise: earn a high point ratio Functional requirements:
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Team 10 Team Members: Warren Chan Alicia Powers Thomas Velky
An Overview • Spring loaded ramps simply transport 'junk mail' to bottom holes • Adversaries are thwarted by a comprehensive blocking scheme
Design Process • Initial premise: earn a high point ratio • Functional requirements: • Unload balls from initial point • Transport across wall • Prevent balls from being deposited on our side • We foresaw difficulties with increasing altitude
The ball kicker pushes the balls off the arc Blocking prohibits opponent from getting balls on our side Main Components Ramp provides a channel for the balls
Pros: fairly simple idea few motorized parts high accuracy of ball placement effectively blocks deploys very quickly little movement required Cons: alignment issues high precision required parts require a lot of material and time parts difficult to reproduce or adjust Points to consider
Start: Power off Pin in ‘up’ position Strings tethered in place End: Power on Pin in ‘down’ position Strings released Pros- releases ramps quickly, easy to operate Cons - small pin could break; if misaligned, pin binds How it works : Release
Pros – fast deployment, can transport all very quickly Cons – requires high accuracy How it works : Ramp • The ramps are self contained appendages • They begin folded, teathered in place • Springs provide energy • High alignment hinges ensure accuracy
Components: Motor mount L bracket Adjustable sliders (X2) Motor Acrylic arm Pros – assures balls go off arc, easily attached to motor, simple Cons - potential for overshooting How it works : Ball Kicker
Two square metal tubes Defense to complement offense Fits in well with other components Pros: easy to launch, no motor required, simple in concept, few parts required Cons: high precision required, poor mobility, energy source questionable How it works : Blocking
Free body diagram and graph Known Constants: Found speed of motor ω = 31.4 rad/sec Calculated torque of motor τ = .149Nm Approximate radius of acrylic r =.0826m Distance of rotation ө = 2π rad Mass of ball m = 4.5g Friction force of plastic μ = .667
Theoretical Calculations Assume power is max τ = .111N*m ΔE = τΔ өΔE = .111N*m x 2 π = .697 J P = τ x ω P =.111N*m x 47.5rad/sec= 5.27W Pmax from energy analysis = 5.27W Fpush = τ /r Fpush = .111N*m/.0826m = 1.34N Fneeded = μ N = .667 x 4.5g x 9.81m/s2 / 1000 Fneeded = .0441N Actual Calculations ΔE = τΔ өΔE = .197N*m x 2 π = 1.24 J P = τ x ω P =.197N*m x 10.5rad/sec= 2.07W Pmax from energy analysis = 5.27W Fpush = τ /r Fpush = .197N*m/.0826m = 2.38N Fneeded = μ N = .667 x 4.5g x 9.81m/s2 / 1000 Fneeded = .0441N Analysis of Ball Kicker
Difficulties to overcome • Building takes longer than planned • The ramping system requires precision • Only three people, less man hours available for work • Time constraints difficult to meet • A lot of fine-tuning required • Availability of kit materials always of concern • Parts not suited for manufacturability • Parts break more often than expected
Simple always wins Low risk of balls misdirected Blocking prevents other teams from scoring Conclusion