156B Week 4

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

• • Ordered and assembled the linear actuator to move the slides

  • Finished 3D CAD design for the entire system

  • Stepper motor for pressing system is working

Accomplishments from Previous Week

• • Ordered and received stepper motor and motor driver. Finished building up the circuit

  • Linear Actuator part came in, finished building up the assembly, in progress of testing the actuator motor control code

  • Finished CAD models of pressing system, holding plate, straw ramp, and motor mount, will 3D print or laser cut them when the material is available

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

• • Press Actuation Design -- Ruiqi

  • Slideholder and Smearing Logic  -- Yuhui

  • Straw Disposal Design -- Lumei

  • Straw Pressing and Holding Mechanics -- Guanhao

  • Arduino control for linear actuators -- Yi

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

• • Pushing with Straw (Prefer this method)

    • Waiting to see more changeable variables other than speed and the pressure on the straw ----- Make it possible to change the distance between the pressing system and the straw storage, so the shape of the straw can be changed

    • Besides speed, pressure and the shape of the contact surface, it would be better if we can change the material of roller. For instance, we can wrap the surface of the straws with a different material.

  • Spinning Method

    • It only has one variable: speed  

    • Too much blood is applied on each slide.

      • It is hard to provide a monolayer.

      • Need to take blood splitting into account.

    • There was a device with spinning method in the past, but it was not popular (People don’t like it).

  • Suggest to go with the straw design

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

• • Report

    • Delete tables and figures that are not ours (done)

    • There should be figures in existing solutions section and background section

    • The figures should be numbered and have captions

    • The figures also have to discussed in the writing

    • For motor, we might want to buy gears available online (done)

  • Concerned about how big the hole on the belt would be

    • The price for conveyor belt is more than $1,000 and is too expensive to experiment with.

    • We decided to purchase a linear actuator bundle (Lead Screw mechanism)

  • Primary goal: produce high quality blood smears

  • Load slides horizontally

  • Could Load straw by rotating

    • We took a look at the toothpick dispenser at a restaurant

    • https://www.bargreen.com/winco-actd-3-toothpick-dispenser-clear-plastic-3-x-2-1-2-x-4.html

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 stability and the force of the pressing system

  • The stability of the straw -- it may slip or rotate when being pushed by the rack

  • The speed of the linear actuator might be too slow to produce a quality smear

  • The quality of the smearing overall

Resources or Information Required but not Available

• • None

Schedule

• • Describe upcoming milestone

  • Update Gantt chart

Budget (list amount spent and amount remaining)

• • Yi

Amount spent: Motor Bundle(3 items) $32.97

Nema17 stepper motor

A4988 driver

Motor mount

Stepper controller driver $14.39

Linear Actuator $ 163.41

• • Ruiqi

Rack and Pinion for stepper motor    $28.51        $16.91

Tax 3.52 Shipping 6.42

Total $55.36

Progress on Report and Webpage

• • Finished Impact on Society

  • Uploaded CAD files