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Team 23

Elliot Snyder, Daniel Cruz-Espada, Yanick Sanchez, Liem Le

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How the Robot Works

  • Telescoping Lift
  • Two Wheel Chassis
  • Geared Claw
  • Goal: Deliver to top of geisel one at a time

LIFT

CLAW

WHEELS

Key Features

Yanick/Daniel

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Parts of Claw

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Double claw strengthens grip

4-40 Bolts

Rubber bands attached to bolts to add friction in the grip

Wrap behind object, helping pull out

Attachment to lift

Open up to almost 180 degrees, close until arms touch

Daniel

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The Claw Can Open and Close

Daniel

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Maximum gripping force

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Geared Motor stall torque stall: 0.315 Nm

Moment arm length L = 3.23 in = 0.082 m

Max Force at mid point of arm = stall / L = 3.84 N

Max Gripping force = 3.84 * # of arms = 3.84 * 4 = 15.37 N (x direction)

3.84 N

3.84 N

3.84 N

3.84 N

0.082 m

0.315 Nm

y

x

Daniel

Torque

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The Telescope Can Rise

Telescoping Lift

  • Goal: Reach top of Geisel
  • One taut line and one structure driven by motor and pulley.
  • Track holds structures in place and delrin slide between.

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Lift Down

Lift Up

3D PRINTED - ACRYLIC ALUMINUM - DELRIN

Delrin Slide

Screw to secure fishing line

3D Printed Pulley- Guides fishing line

Acrylic Track

Elliot

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Looking at Risk

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Risk Reduction Test

  • Highlighted Key Issues on riskiest component
  • Proved Function
  • Showed height range
  • Prompted solution neutral concept generation

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Elliot

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Testing Ideas

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Non Geared

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Friction motor mechanism that collapse the motor onto the wheel

Gap base to creates space for claw for lower objects

Early Prototype of Drivetrain

  • Friction Drive

Yanick

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Super Speed!

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Two Wheel Drivetrain

  • Powered by two geared motors angled at 90 degrees sideways
  • Low Friction delrin bar on the back for support

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Base of chassis

Rubber ring for friction

Angled geared motor

Acrylic wheel

Low friction delrin bar support

Yanick

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Analyzing the Wheel

The objective of this analysis is to determine if the motor has enough maximum torque to move the maximum weight.

Liem

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Crunching The Numbers

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Motor: Geared Motor

  • Max Energy in 60s (J): 9.894
  • Max Power (watts): 0.1649
  • No Load Speed (rad/s): 2.094
  • Stall Torque (Nm): 0.315
  • Moment Arm Length (m): 0.13
  • Stall Angle (deg): 58 +- 2

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Material: Metal and Acrylic

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Constant Variables:

Mass of car: 0.926 kg

Distance car needs to move: L = 14” or 0.3556m

Desired time of travel: 60s

Coefficient of Friction(Acrylic) = 0.15

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FBD Analysis

Liem

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Calculations and Results

  • With the two geared motors, the drive train has enough torque with a safety factor 1.3003 of to carry the lift mechanism plus claws.

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  • If more weights are added to the the robot, then it will be harder for the motors to push the robot.

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  • This function translated to the real wheels

Possible Issues

  • The rubber grip on the wheel will prevent the motor from maximizing its power.
  • Without wheels at the back, there will be more drag friction
  • The base is too light to carry a heavy top.

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Liem

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Putting it All Together

Lift Function -

  • 9 seconds w/o objects
  • Can lift up to 300 grams/All objects

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Reliable Score = 85 Points

  • Gearbox on 2nd Level
  • Legos on Dorm Floor

Max Score = 145 Points

  • Gearbox on 2nd Level
  • Triangle on 2nd Level
  • Wrench on Dorm Floor
  • Legos on Dorm Floor

Elliot