156A Week 9

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

• • Thought of possibly using springs with individual plates to allow for different SLK force measurements

    • "Keyboard" idea where plates could be pressed down and give a reading anywhere in the testing area

    • Problems:

      • Sections where SLK heads do not fully engage with plates, creating a moment at the fixed joint where the spring is, creating huge deflection

      • Springs aren't very accurate

      • How would we measure the deflection of the spring to calculate force?

        • Laser interferometer, ultrasonic sensors, camera

Accomplishments from Previous Week

• • Overview of project

  • Diving into CAD models of the SLK fixture provided to us by our sponsor

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

• • Coming up with designs and presenting them to sponsor via Google Slides

    • Damon: looking into array of springs in tray to measure force

    • Richard: looking into mounting feature w/ sensor on SLK head to determine force

    • Sam: looking into single load cell with plate to determine force

    • Daniel: looking into FlexiForce force sensors

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments

• • (Tues 2/28 met in-person) Sponsor gave us Solidworks files of machine to help us better understand the mechanisms of the machine. We were tasked to review these Solidworks files and come up with possible design solutions

Instructor Comments from Last Meeting and Actions Taken to Address these Comments

• • Research sensors and further define problem. Looked into load cell sensors, ultrasonic senors, and interferometers

Risks and Areas of Concern (i.e. show stoppers)

• • If springs were a viable option to support the load of 10lb - 1000lb. 

    • How precise would they be?

    • How would we measure deflection of the spring?

  • Load cells are very expensive; how can we design it such that we only need to use one?

    • Cannot use a load cell for each individual SLK head, as there are up to 24 in one test

    • A force on a flat plate with a load cell in the center would create a moment that would affect the force reading/damage the load cell or plate. How can we counteract this moment?

Resources or Information Required but not Available

• • Further understanding of the mechanisms of the machine were not fully understood as of yet. More questions were asked.

Schedule

• • To look into specific ideas given to us by sponsor (using 1 load cell only, mounting sensor to head of SLK) and to present findings next week.

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • N/A

Progress on Report and Webpage

• • N/A