156B Week 4

MAE156B Week 4 Progress Report

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

• • 6 casts are fabricated and should be tested tonight. The tests should tell us what paper configuration and grain works best.

    • Currently transitioning out of the materials testing phase and into the layer design phase and the grain design phase

  • New fabrication method using heat sealed plastic was finalized. This should allow for much faster prototyping in the future. Right now we are still using slow to cure silicone sealant due to the unavailability of the other plastic.

Accomplishments from Previous Week

• • Hole punch for heat-sealed plastic

  • Casts Fabricated:

    • 80mL Polystyrene grain jammer (RTV sealed)

    • Intervening layer jammer (RTV sealed)

    • Coffee grain jammer with copper wire (RTV sealed)

    • Hinged layer jammer (RTV sealed)

    • Fully circular layer jammer (RTV sealed)

  • Casts getting tested tonight:

    • 60mL Polystyrene grain jammer (RTV sealed)

    • Intervening layer jammer (RTV sealed)

    • Coffee grain jammer with copper wire (RTV sealed)

    • Hinged layer jammer (RTV sealed)

    • Fully circular layer jammer (RTV sealed)

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

• • Solve grian bunching (Dylan)

  • Determine ideal grain/layer ratio (Brian)

  • Start working on the full size cast (Kerrianne and Olesya)

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

• • In Person and by Phone (1/30/18)

    • Normalizing casts by volume is acceptable; it wasn't feasible to continue normalizing them by mass due to the low density of polystyrene

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

• • Concern - ambiguity of the expectations from the sponsor. Actions taken - the sponsor was sick and did not attend the meeting. We are hoping to have a meeting on Monday about this issue.

  • Comment - glass bubbles, such as those used to dilute explosives, may be used as grains. Actions taken - glass bubbles are rigid-walled, so they are not compressible enough to use in the cast

  • Comment -  Consider "muscle wire" (instead of shape memory alloys) as a method of conforming the cast shape to the arm. Actions taken - muscle wire requires either heat or current to contract, which places a power supply requirement on the cast (either to produce the current or to maintain heat). This may not make it more desirable than bending the cast by hand as long as the cast remains flexible enough

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

• • The focus of the project and miscommunication with the sponsor.

Resources or Information Required but not Available

• • N/A

Schedule

• • Finalize material options

  • Start/ Get ready for the full size prototype production

Budget (list amount spent and amount remaining)

• • Amount remaining $2289.22, $110.78 spent

Progress on Report and Webpage

• • Will be working on the report tomorrow before class