Automated Gravel-Bag Loading Mechanism

ME 195B: Final Presentation

Professor James Mokri

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Nathan Ju

Nicholas Laschkewitsch

Enrique Luna-Ramirez

Eric Luna-Ramirez

Seiji Soares

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San José State University

Mechanical & Aerospace Engineering Department

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May 11, 2018

Presentation Outline

• Motivations
• Literature Review
• Objectives and Specifications
• Design and Methodologies
• Test, Results, and Prototype
• Conclusions
• Future work�

Source: ABC7 News

WATER

February 2017

• Heavy, persistent rainfall across northern and central California
• 202,000 residents evacuated
• $1.5 billion in reported losses

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Source: NOAA National Centers for Environmental Information (NCEI) U.S. Billion-Dollar Weather and Climate Disasters (2017). https://www.ncdc.noaa.gov/billions/

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Impact of the Project

• Faster method of producing sandbags
• Improve worker safety
• Enhance flood control response
• Minimize flood damages

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Floods are the most common natural disasters in the United States.

Source: San Francisco Chronicle

Literature Review: Bag Filling by Frontloader

Source: https://www.youtube.com/watch?v=0gNbiUQnJjE

Advantages

• Compact
• Cost effective
• Can fill many bags at an instant

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Disadvantages

• Loads bags at a rate of 750 bags per hour
• Requires a total of three people for operation
• Bags need to be prepared prior to loading the bags

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Literature Review: Bag Filling by Hand

Advantages

• Simple task
• Shovel is the only tool required

Disadvantages

• Slow
• Labor intensive
• High labor cost
• Requires many people for high output

Source: VideoBlocks.com

Objectives and Specifications

• Load more than 1,400 bags per hour
• Open bag to fit over the 10 in. x 0.81 in. insert of the clamp mechanism
• Position bag into the clamp opening within +/- 0.1 in. accuracy or better
• Total bag capacity of 4,000 bags
• Total weight under 100 lbs�

• Load at least 1,400 bags per hour
• Open bag to fit over the 10 in. x 0.81 in. insert of the clamp mechanism
• Position bag into the clamp opening within +/- 0.1 in. accuracy or better
• Total bag capacity of 4,000 bags
• Total weight under 100 lbs
• Easily portable�

• Debris and dust
• Lubrication

• Spring in dirty environment
• Bag stop

Initial Designs - Bag Hopper

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Rollers Design

Linear Actuator Design

Initial Designs - Bag Hopper

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Initial Designs - Bag Grabber

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Final Design - Overall Bagging Mechanism

Theories & Physical Principles: Grabbing Arms

Electronics

• x2 Arduinos
• x1 Motor driver board
• x1 Digital stepping Driver
• x6 Limit switches
• x1 12V Brushless DC motor
• x1 Stepper motor with gearbox
• x1 Linear actuator
• x1 12V Battery

Source: Norwegian Creations

Source: Norwegian Creations

Conclusions

• Did not meet the 470 bags per hour rate
• Were successful in picking up bag, opening the bag, then grabbing the bag.
• Requires two people to transport
• Both mechanisms work independently
• Sensor calibration and clearance issues still persist

Valuable Takeaways

• Finalizing a design during the design phase (fall semester) will save a lot of time during fabrication and prototyping (spring semester)
• Modular mechanisms need at least double the work time to synchronize and calibrate together
• Always be mindful of tolerances

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Future Work & Improvements

• Reduce weight by changing the material
• Reduce operation time
• Increase durability by weatherproofing design
• Full automation with limit switches and PLC integration
• Finalize bracket design
• Acquire a vacuum motor in lieu of a shopvac

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Thank you!

References

• Golden Gate Mechanical, Inc.
• San José State University
• ABC 7 News
• San Francisco Chronicle
• NOAA National Centers for Environmental Information (NCEI) U.S. Billion-Dollar Weather and Climate Disasters (2017). https://www.ncdc.noaa.gov/billions/
• Footage Firm / Video Blocks
• Norwegian Creations