156B Week 8

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

• • Analysis: Mostly Completed

    • Actual motor torque-pulse requirement

    • Equivalent thrust on bearings

    • According to GeckoDrive, the half-step and micro-step torque-speed curves are the same

  • Design: Completed

  • Fabrication: Waiting on belt clamp plate, shaft coupling (ordered, waiting to arrive)

  • Tests: Waiting for non-magnetic screws to arrive to test for distortion in MRI

Accomplishments from Previous Week

• • Drilled and tapped hole pattern on mounting plate

  • Purchased nylon screws for mock tooling

  • Debugged stop button, motor disabled button in LabVIEW, digitalRead for limit switches and current sensors

  • Connected and debugged limit switches in LabVIEW

  • Completed assembly drawings with part numbers and high-resolution CAD

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

• • Perform time and distance tests to see if carriage moves as expected (Ola, Brian, Sally)

  • Have PCB ordered, complete fiber optic communication (Alex)

  • Replace limit switches with optical sensors and debug if necessary (Brian)

  • Complete assembly with belt end clamp (Ola, Sally)

  • Finish updating webpage (Sally)

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

• • Hole pattern on mounting base, 1" spacing from the center (Mark, 5/15)

    • Completed, attached to the carriage

  • Consider using Scotch-Brite to create satin finish on the aluminum parts (Mark, 5/15)

  • Approved mechanical design, robust (Mark, 5/15)

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

• • Bearing Analysis - Equivalent Thrust (in person, 5/15)

    • Used sum of moments to determine equivalent thrust on one ball bearing

    • Maximum thrust: approximately 3.92 lbs

    • Maximum thrust capacity on one ball: approximately 9.14 lbs

    • Conclusion: reaction forces created by moment well within range

  • Bring completed design to show sponsor

    • Showed Mark, who is in charge of fabricating parts for the CFMRI

    • Sponsor, Robert, was unavailable that week but we will be presenting it to him Thursday, 5/22

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

• • Professional version of LabVIEW is required to create an .exe file, which is available in Steve Robert's lab (via email, 5/14)

    • Note: .exe files run faster than original LabVIEW file

Risks and Areas of Concern

• • Fiber optic connections

    • ordering fiber optic cable, PCB

• Optical sensors

  • ordering reflective photologic sensors (order sent, but not processed yet)

Resources or Information Required but not Available

• • None

Schedule

• • Prototype with fiber optic communication

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • Total: $1500

  • $502.24 spent, $997.76 remaining

Progress on Report and Webpage

• • Report

    • revisions based on comments on the first draft

    • 'impact on society' section in progress

    • began compiling the appendix

  • Webpage

    • revisions to front page based on critique

    • uploaded files under 'Multimedia'

    • updated budget and parts under 'Reports'