156B Week 6

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

• • Fabricating full-length prototype for cast

    • Issues manifested while scaling up: in the process of solving

  • In the process of solving grain bunching

  • Troubleshooting and solving persistent nozzle leakage with RTV

Parts Arrived:

• • Velcro

  • Silicone sheets

Parts in Shipment:

• • Ball valves

  • Nozzles

Accomplishments from Previous Week

• • Complete segmented, wire-reinforced grain section for the large cast

    • Segmentation is to avoid grain jamming

    • Improved upon heat-sealed grain pouch seal by adding extra cloth at the seams

    • Fixed copper wire location by using RTV to glue it to one side of the cloth’s interior

  • Complete layer section for the large cast

    • Hinged layers increased from 3-4 pattern to 5-6

  • Research dimensions and thickness requirements

    • Results of beam bending analysis:

      • Increasing the thickness by a factor of n increases stiffness by n3

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

• • Create a cast that is the length of an arm (Olesya)

  • Finalize overlapping cast and test (Brian)

  • Investigate solution to heat-sealing issues: wrinkling of plastic causing gaps in seal (Dylan)

  • Obtain data on varying number of copper wires within the grain pouch (Kerrianne)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments

In Person (2/13/18)

• • • In addition to increasing stiffness, does copper wire help maintain the cast’s cylindrical shape?

      • Copper is malleable: it does not provide much structural support pre-vacuum

    • The report should contain the necessary documentation to lay the foundations for the CB3M team to improve upon their research

      • Additions made to experimental procedure on sample preparation to instruct research team on how we fabricated the final prototype

Instructor Comments from Last Meeting and Actions Taken to Address these Comments

In Person: Proof-of-Concept Presentation (2/7/18)

• • • Beam bending analysis: relative/qualitative instead of quantitative

    • Segmenting grain pouches to prevent loss of stiffness from grain bunching

      • Both addressed in Accomplishments from Previous Week above

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

• • In Person: Proof-of-Concept Presentation (2/7/18)

    • Have we tried any kind of wire besides copper?

      • Will investigate wire material with a focus on varying ductility

  • Email: Presentation Feedback (2/13/18)

    • Filter information to keep the presentation succinct: the slides had too much information to follow well or maintain attention

    • Make sure the audience understands the test results and their significance: flesh out the theoretical basis and project background

    • Improve oral presentation skills: rehearse what to say to avoid uncertain speech and reading from slides

Risks and Areas of Concern

• • Difficult to heat-seal long plastic sheets with no gaps at all

Resources or Information Required but not Available

• • Longer sheets of plastic and larger capacity for heat-seal length

Schedule

Budget (list amount spent and amount remaining)

• • Amount remaining $2259.22, $140.78 spent

Progress on Report and Webpage

• • Front page of webpage is done except for final design and some additional drawings/pictures

  • Added an outline for final design’s fabrication steps