Team #24

Blase Londono, Martin Campos, Josiah Hallett, Sean Yeow

INSERT PHOTO OF ROBOT ON THIS SLIDE

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WHAT WAS OUR STRATEGY?

• Inspired by the simplicity of ‘spherical’ coordinate systems
• Pan ↔ 𝛉
• Tilt ↔ ɸ
• Extension ↔ ⍴

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• Begin → Immediate first extension → rotate / tilt → rings → second extension → Sun God

Blase

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1

STRATEGY MOCKUP

Sean

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STEP 1

COLLECT RING(S)

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2

STRATEGY MOCKUP

Sean

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STEP 2

PLACE ON SUN GOD

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STRATEGY MOCKUP

Sean

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STEP 3

REPEAT

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FOUR MAIN COMPONENTS

Rotating Base (Sean)

Tilting Mechanism (Martin)

First Extension (Blase)

Second Extension (Josiah)

All

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ROTATING BASE

Sean

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4

Mounting Brackets

GM9 Motor

Screw Jointed PLA Bearings

24T Gear

192T Gear

TILTING MECHANISM

• Rotates arm elevate or lower arm

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• 7:1 Gear Ratio as a mechanical advantage

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Martin

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PRIMARY EXTENSION MECHANISM

• Rack and pinion mechanism provides linear extension

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• 2:1 gear ratio ensures slider can overcome forces of friction and weight of acrylic rings

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• Pinslot hardstop ensures extension remains constrained within base

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Blase

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PRIMARY EXTENSION MECHANISM

Blase

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PRIMARY EXTENSION MECHANISM

Blase

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SECONDARY EXTENSION MECHANISM

• Lightweight extension to the arm mechanism

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• Collapsible starting configuration

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• Securely hold rings and drop at the desired height

Josiah

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DESIGN PROCESS - Risk Reduction

• Initial risk reduction:

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• TOO HEAVY!!!

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• Stalled early

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• Bulky, topheavy

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• Replaced with two new components!!! FIRST AND SECOND EXTENSION

Josiah

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ANALYSIS: TILT MECHANISM

• First design FAILED!
• Thin support
• Stress concentration
• Too many parts

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• Design changes:
• ⅛” acrylic replaced with stronger sheet metal
• 7:1 gear ratio! (84:12)
• Arm extension fastened flush onto center of output gear

Martin

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ANALYSIS: TILT MECHANISM (CONT.)

OBJECTIVE

Find output torque needed to lift arm at full extension with weight of arm, claw and rings

ASSUMPTIONS

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• No power loss (optimistic)
• No friction between gear and wall (optimistic)
• Coulomb friction (optimistic)

Martin

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ANALYSIS: TILT MECHANISM (CONT.)

DERIVATION

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Worst Case Load at full extension carrying 3 rings (10g)

Martin

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ANALYSIS: TILT MECHANISM (CONT.)

RESULTS

• Max Torque Measured (with a mass of 0.58kg at full extension) = 1.445 N*m
• Percent error = 59.86%
• Bearing needed as output shaft will wobble once attaching arm extension
• Redesigned arm to reduce weight (>100g removed)
• Redesigned arm to extend range (+4” of workable extension added)

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GEAR RATIO

FACTOR OF SAFETY

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Martin

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PERFORMANCE IN-FIELD

• WE CAN SCORE: [10] IN A MATCH
• [0] rings [1] held

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• WITH INFINITE TIME WE CAN SCORE [1]
• [0] rings [1] held
• [1]/21 rings

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• IN A THEORETICAL INFINITE MATCH WE SCORE [3200]
• [10] rings [0] held

Josiah

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THANK YOU!

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