1 Team Mieux Critical Design Review ASME Bulk Material Transporter AME 470 Ltd. December 7, 2004

2 Team Mieux Critical Design ReviewDecember 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 ReviewDecember 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 ReviewDecember 7, 2004 AME 470 Ltd. August 24Project Introduction September 14Concept Selection October 5Trade Studies of Key Issues November 11 Concept Design Proposal and 3-D Models November 30In-House Demonstration Development Timeframe 3 Weeks for Concept Generation 7 Weeks for Full Design 3 Weeks Manufacture/Assemble/Troubleshoot What this means….

5 Team Mieux Critical Design ReviewDecember 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 ReviewDecember 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 forwardVehicle climbs stair Ascension completed

7 Team Mieux Critical Design ReviewDecember 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 ReviewDecember 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 ReviewDecember 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

10 Engineering Analysis- Chassis Design Team Mieux Critical Design ReviewDecember 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

11 Team Mieux Critical Design ReviewDecember 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 ReviewDecember 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 ReviewDecember 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 ReviewDecember 7, 2004 AME 470 Ltd.

15 Team Mieux Critical Design ReviewDecember 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 ReviewDecember 7, 2004 AME 470 Ltd.

17 Team Mieux Critical Design ReviewDecember 7, 2004 AME 470 Ltd.

18 Team Mieux Critical Design ReviewDecember 7, 2004 AME 470 Ltd.

19 Team Mieux Critical Design ReviewDecember 7, 2004 AME 470 Ltd.