156B Week 7

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • All of the kinematics, opening mechanisms, closing mechanism, and safety locks put into comparision table to help with design decisions

  • Decided to move forward with winch design

  • Prototype fabrication for winch design started

  • Waiting on materials to complete prototype fabrication

Accomplishments from Previous Week

• • Compared all of the different aspects of the device previously considered

  • Decided to move forward with a winch design that uses constant force springs, a crank to open, and a gear lock for safety

  • Purchased some of the materials for the prototype

  • Began the fabrication of the new prototype

  • Created list of the fabrication aspects that still need to be completed and materials that need to be purchased

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Complete the new prototype (Team)

    • Finish drilling holes into side panels and mounts - Tuesday May 15 (Justin)

    • Lasercamm additional pulleys and mounts - Tuesday May 15 (Travis)

    • Purchase braided wire - Tuesday May 15 (CJ)

    • Assmble the prototype without the wire - Wednesday May 16 (Team)

    • Add wires to the prototype once they arrive

  • Conduct time trials of the prototype - Sunday May 20

  • Analyze time trial results to obtain statistical results - Monday May 21 (Stephanie)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • Dr. Mazzei was unable to meet with us this past week

  • We emailed him pictures of the updated designs and he liked the concepts

  • We are meeting with him this week and will discuss the designs more in depth to get adequate feedback

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• • Notes from Dr. Delson about presentation given on 5/8/12:

    • He would like to see a numerical analysis of the linear slider that includes fricition values

    •  Crank concept:

      • crank idea is a good way to get a large mechanical advantage

      • FEA analysis of plate is not the critical part but the crank force and bearing friction is critical

    • Panini presse:

      • Nice CAD and alternative concepts

    • He would like to see a comparision table of all concepts with pros and cons

    • He would like to see concepts combined, but do this systematically

      • Categorize and compare the kinematics, opening force, closing force, safety 

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• • Notes from classmates from presentation given on 5/8/12:

    • About presentation:

      •  Add more animations and pictures to clarify the designs

      • Analysis is difficult to understand

    • About project:

      • "I like your current design, but to avoid jamming by the metal rods, maybe incorporate the Panini Design."

      • "Consider using a sleeve for lifting sliding mechanism. "

      • "A possible alternative to traditional springs is to use air springs. They are used in some extreme pogo sticks (they are only compression though). It could reduce weight. Panini press seems good, just needs improvement on getting springs on. Bungee cords?"

      • "Consider using metal bushings or self-aligning bearings to solve levelling problem"

      • "I like the spring/pin design. For the Panini press maybe attach the springs at a unstretched angle and then have a crank to somehow stretch the springs. Maybe a foot pump?"

      • "For most of the designs, what stops them from snapping shut while opening? Say if someones hand slips off the handle?"

Risks and Areas of Concern

• • Will braided wires have the effect and strength that we want for our device

  • Does the crank provide enough mechanical advantage to ensure the device is easy to open

  • Will the gear lock be strong and reliable enough to be a valid safety mechanism

Resources or Information Required but not Available

• • None

Schedule

• • Complete fabricationa and assembly of prototype - May 19th

  • Test prototype with clear fluid - May 20th

  • Obtain stastical results of tests conducted - May 21st

Budget (list amount spent and amount remaining)

• • Spent: $230

  • Remaining: $2270

Progress on Report and Webpage

• • First draft of report returned and appropriate adjustments to formatting are being made

  • New design concepts are being written in to the report

  • Webpage needs to be update accordingly, in particular the multimedia page needs to be updated