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Team Mieux
Critical Design Review
ASME Bulk Material Transporter
AME 470 Ltd.
December 7, 2004
2 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
ASME Competition Overview
People everywhere have difficulty transporting bulk materials in moderate amounts, particularly when the materials must be carried up stairs or over hills and rough terrain, or when the space available for moving the materials is too small to allow conventional automotive vehicles to be used.
•Design a prototype vehicle to transport rice up and down a stair setup
•Stairs are between 3.5” and 4” in height
•Platforms are 12” X 12”
•Competition judged by amount of rice transported in a 10 minute time frame
Competition Course
3 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
ASME Design Requirements
•12V battery power source (composed of AAA, AA, C, D batteries) in addition to two 9V batteries
•Controlled via an Umbilical Cord or a Radio Controller
•Vehicle must fit into a volume of 25cm X 25cm X 30cm (packaged position)
•Device cannot touch more than two steps at a time
•Device must touch each step sequentially
•Device can only have one pilot AME 470 Ltd. Requirements
•Total Budget of $500
•Various manufacturing constraints
4 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
August 24 Project Introduction
September 14 Concept Selection
October 5 Trade Studies of Key Issues
November 11 Concept Design Proposal and 3-D Models
November 30 In-House Demonstration
Development Timeframe
3 Weeks for Concept Generation7 Weeks for Full Design3 Weeks Manufacture/Assemble/Troubleshoot
What this means….
5 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description
Key Features
•4 Wheel Locomotion
•Rotating Counterbalance
•Arched Chassis
•Independent Rear Wheel Drive
•Front Drive train
•Rear Mounted Rice Container
•Rear Stabilizers
•Umbilical Control – Mechanical Switches
•3 Speed Settings
6 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description Continued
Vehicle Locomotion
Vehicle drives forward Counterbalance rotates backwards, and vehicle enters into the raised position
Vehicle drives forward
Counterbalance rotates forward Vehicle climbs stair Ascension completed
7 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description Continued
• Counterbalance Causes vehicle to enter raised position
•Counterbalance increases normal force between front wheels and stairs•Prevents Wheel Slippage
•Vehicle turns from raised position•Rear Wheels Independently Actuated
•Vehicle reverses down stairs to return to beginning of course•Speed control allows for controlled descent
8 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description Continued
Rice Container
•Solenoid acts as hatch release
•Hinged Door
•Shell Design – to reduce weight•Plastic sheets seal container
•Vehicle dumps rice from raises position•Gravity forces rice from container
9 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description Continued
Controls
•Manual Controls – no automation
•Mechanical Switches•DPPT, SPST, Pushbutton•Momentary contact drive switches
•Back EMF Brakes•Brake switch creates a short across the motor
•Variable Voltage Speed Control•Switch between 3 smaller voltage sources
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Engineering Analysis- Chassis Design
Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
•Assign Wheel Centers Coordinates Based on wheel Diameters
•Calculate points x’ and y’
•Calculate length of L’
•Plot L’ vs. length of Chassis
•Update Wheel center positions
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11 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Engineering Analysis- Chassis Design
•Minimum required shape includes 0.1” tolerance
•Full arch shape selected to avoid stress concentrations
12 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Engineering Analysis - Counterbalance
•Maximized counterbalance arm length for ASME geometric constraints
•Counterbalance arm length - 7.5”
•Static Analysis of moments about the rear wheel axis
•Counterbalance Weight – 2.7lbs (minimum)
•Range of motion
•Constrained by vehicle geometry
•Vehicle must rotate 40º
•Counterbalance must not contact ground
13 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Engineering Analysis – Crank Design
Crank Slider Mechanism
•Reasons for Selection
•Wide range of motion
•Ease to manufacture – Three pieces
•Ability to assign limit positions
•Technical analysis
•Max torque of 9.5 in-lbs
•Range of motion of 148º
14 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
15 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
Product Description Continued
Design Advantages and Disadvantages
Advantages•Agility - 0 turning radius•Ability to conform to various
16 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
17 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
18 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
19 Team Mieux Critical Design Review December 7, 2004
AME 470 Ltd.
