156B Week 3

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

• • Chose major components and specific vendors (thrusters, housing, batteries)

  • Exploring materials to use for piston

  • Working on a finalizing a support system to fully constrain the linear actuator

    • Want to prevent rotational and linear motion in all directions

  • MCU will be a SparkFun 9DoF Razor IMU M0 instead of Raspberry Pi Zero in the interest of power consumption (~10 mA from new board)

    • Board runs on Arduino and has a powerful processor

Accomplishments from Previous Week

• • Created list of items to purchase with approximate costs and received finalized budget from sponsor

• received CAD of antenna unit and information on how antenna attaches to the AUE, updated CAD

• rearranged components in the design for space efficiency

• decided on industrial reciprocating seals for the piston.

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

• • Choose how to secure the linear actuator - Michael

  • Choose how to arrange and secure batteries - Doris

  • Talk to Tom about fabricating "wedding cake" inner housing, choose material, send in order for materials - Duncan

  • Choose how to attach piston to linear actuator - Zach

  • Study how to code new MCU and ensure it meets our needs - Hugo

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

• 5 L is an acceptable design, though batteries can be potentially packed around the linear actuator to reduce space use (4/14, email)

  • Rearranged to fit batteries around actuator in the CAD

• Suggested SparkFun 9DoF Razor IMU M0 for the controller instead of Pi Zero (4/14,email; 4/18, in person)

  • Searched up the controller and made changes to the CAD

  • read up on the controller briefly and learned of its capabilities.

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

• Should check to see if the chosen linear actuator needs to draw power when static.

  • Michael checked with Firgelli, actuator does not draw power when under static load.

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

• • None

Risks and Areas of Concern

• • Ability to maintain antenna out of the water and up right when at surface

• The unit might wobble when the thrusters activate, since the weight is pretty evenly distributed across the unit.

• Not being able to efficiently constrain the inner components, especially batteries.

• MB6 mounting bracket from Firgelli Automations is currently out of stock

  • Looking at other mounting options and/or custom fabrication of mount

Resources or Information Required but not Available

• • None

Schedule

• • Ordering first essential components this week

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • $0 spent, $1400 remaining

  • Finalized budget of $2000, less the $600 lab fees

Progress on Report and Webpage

• • Complete Impact on Society section by midnight Friday