156B Week 4

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

• • currently fabricated prototypes of different routes from our initial conceptualization and sponsor feedback

  • Spring hair bundle lock has failed so far

  • ratchet mechanism needs better feedback indicators

  • plastic bag sealer needs to be made a bit more transportable and handheld 

Accomplishments from Previous Week

• • created a lighter, smaller, and more portable version of the plastic bag sealer

  • created a (failed) prototype of a smaller spring mechanism cord lock with a 1cm diameter hole

    • doesnt fit specifications and is too weak 

  • further explored different devices and discussed/researched other routes at a deeper level

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

• • justify the route we choose 

  • overcome challenges for the said route

  • look into manufacturing for the device

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

• • Meeting 1: Friday 1/24

    • ratchet mechanism is too big ~ wants it down to about 50% of the size while retaining the hole size

    • diameter of a bundle should be about 1cm 

    • prefers spring mechanism to ratchet mechanism because of feedback

  • Meeting 2: Tuesday 1/28

    • satisfied with 66% size of ratchet mechanism

      • disposability makes more money for the companies

    • tape mechanism device

      • electrical/fluid resistant tape would work best

      • "sexier" than the locking devices

      • try to limit the size of the tape tab that is left on the hair

        • double-sided tape could fix this issue

      • more complex, so needs to be sure that it will be consistent and reliable

    • procedure -- 2 to 3 hours usually, so fluid resistant tape is best

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

• • ratchet

    • doesn't give obvious feedback

    • concept is good but it doesn't give the feedback we want

    • include stronger indicators

  • give more justification for route choices

    • verify assumptions

    • not just liking the concepts or disregarding because something is complicated 

    • justify through engineering standpoint

  • define "tight"

    • could have a high pressure feedback click 

  • include both locking feedback and tightness feedback

  • with plastic device: will there be tiny particles falling off in the head

  • look more into manufacturing

    • likely will be injection molded

  • priority

• • 1. justify design

    2. overcome challenges

       1. indicators and feedback

    3. manufacturing 

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

N/A

Risks and Areas of Concern

• • using a spring mechanism at the size specifications the sponsor wants is not feasible 

    • walls of the parts are too thin and weak and the force of pressing down on it or the spring force can break it

    • the spring length will cause the device to be longer than what would be feasible, because we need space for the hole, the spring, and other necessary parts

  • shrinking the ratchet mechanism down THAT much isn't feasible, but it can be made smaller 

  • moving towards the tape dispenser mechanism, we want to find a way to have the taping part not limited by the diameter of the bundle, in case theres extra long hair or extra thick hair

Resources or Information Required but not Available

N/A

Schedule

• • Coming up we have the design review presentation

Budget (list amount spent and amount remaining)

Progress on Report and Webpage

• • Engineering Standards will be done by Friday, 1/31