156B Week 9

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

• • Finished the prototype with basic functions.

  • Further iterations on the current design to improve the functioning prototype, including adjust the position of the stopper by 2 dc motors and creating interface and user manual for sponsor.

Accomplishments from Previous Week

• • Finished the lead screw mechanism for straw stopper to adjust corresponding distance for different straws.

Fig.1A&B Lead screw mechanism for adjusting distance between stopper and storage

• • Finished the improved mount for the pressing motor, where a balanced force can be applied on two straws without tilt.

Fig.2 New pressing mount

• • Further researched on the standards and social values.

  • Decided the knowledge of absolute position to be unnecessary since interruption during the smearing is a low probability event. The initial position of the slide holder can be marked onto the linear actuator and if the interruption ever happens, the user can manually rotate the coupler on the linear actuator to recalibrate.

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

• • Improve the report and poster, appointment in writing center (Lumei Xue, Ruiqi Wang)

  • Cut the acrylic base for the whole device and print all finalized 3d parts on Connex (Yi Cui)

  • Write user manual for sponsor(Yuhui Shen)

  • Improve the team website (Guanhao Fu)

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

• • Will meet sponsor on Friday

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

• • Date 2/28, in person during presentation

  • Change the initial position of the slide holder to minimize the delay before smearing

  • Cultural factor not applicable for the project

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

• • None

Risks and Areas of Concern

• • The two motors used for the gap adjustment have different RPM and the screw shaft shakes. Timing belt and gears can be used to synchronize the two screws and a guiding plate can be sued to fix the position of two screws. The problem can be solved but seems to be too complicated

  • The tape used on the slide holder lost friction after we glued it onto the slider holder.

  • The straw might rotate when loaded onto the ramp

Schedule

Budget (list amount spent and amount remaining)

• • Amount spent: 323.88

  • Amount remaining: 2276.12

Progress on Report and Webpage

• • Second draft of the report was done and was fixed after peer review

  • Presentation slides were uploaded and CAD files were updated