156B Week 4

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

• • We are prepared to propose a bill of materials for our prototype to our sponsor on 4/21.

  • We are also ready to begin fabrication on all parts necessary for a hardware demonstration.

  • Our goal to to demonstrate the motor operating the winch at different speeds during the hardware presentations on 4/28.

  • The Dynomometer test failed.

Accomplishments from Previous Week

• • We have completed a detailed 3-D model (complete with fasteners) of both the winch and the pressure case. The internal chassis which holds the motor, battery, and controller has also been fully designed.

  • We have a complete a bill of materials for the fabrication a prototype capable of lowering itself from a buoy at different speeds.

  • Tested the metal-rubber oil seals in seawater for 6 days. After a period of 3 day, we found that after this period, rust did not develop on the painted areas of the seal, and that the spring could still be stretched without breaking.

  • Code is written for reading the motor encoder in forward and reverse.

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

• • Order rubber O-rings, stainless steel shaft, nylon gears, journal bearing, plastic eyebolt, and spectra cable on Monday 4/21. -Thomas

  • Fabricate both delrin endcaps. -Thomas and Jebsen

  • Machine schedule 80 pipe. -Thomas and Jebsen

  • Fabricate motor mounting plate. -Thomas and Jebsen

  • Fabricate motor coupler. -Matt

  • Test the risk reduction setup test with the seal that has been in seawater for 6 days. -Johnathan

  • 3-D print the winch casing, top, and protective sleeve. -Matt

  • Assemble the pressure case and winch. -Everyone

  • Complete control code for adjusting the speed of descent. -Merlin

  • Troubleshoot control code and hardware. -Everyone

  • Begin Hardware demonstration presentation. -Everyone

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

• • John told us to check up on the availability of fishing reel parts that could be used for the production of more instruments. We found that level wind screws, followers, and other parts are available in small quantities from fishing reel repair shops.

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

• • none

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

• • None

Risks and Areas of Concern

• • There is a risk that the weight of winch and pressure case assembly will sink the surface buoy. We do not know exactly how much the surface buoy weighs, so estimates of buoyancy forces are inaccurate.

Resources or Information Required but not Available

• • We do not have the surface buoy, or a detailed spec sheet for the surface buoy.

Schedule

• • The hardware demonstration presentation is on 4/28. Our goal is to demonstrate the pressure case lowering itself at different speeds.

Budget (list amount spent and amount remaining)

• • We have spent $120 through UCSD. Amount remaining- aproximately $280.

  • We have not purchased any parts through SPAWAR. Amount remaining-TBD

Progress on Report and Webpage

• • The front page has been updated.

  • CAD images of the pressure case/ winch assembly will be uploaded to the "Multimedia" tab on Monday.