Week 6

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

• • Plate:

    • Designs pending: 

      • crank gear ratio and actuator length analysis

      • belt tension and spring steel compliance analysis

      • plate-bearing retainer not yet designed (but should be clearance)

      • hard stops not yet designed; no word yet from Ernest as to why old prototype used steel pin on aluminum hard stop.

    • Plate and bearings arriving week 6; test plate machining using plastic material in machine shop (name?)

  • Testing rigs: ready to order and assemble

Accomplishments from Previous Week

• • Report and website drafts updated

  • Simple press-fit aluminum puck made by machinist on campus (Mark) to get a feel for suggested pulley stock thickness;

    • Response: upgrade the size of the pulley stock to allow for greater wall thicknesses

    • Crank could be cut out of stock if thin enough pulleys can't be found (would be up to $90 for the 8"/12" rod though)

  • Compliance bearings will be on outside of pucks, not inside since belts can't go long enough otherwise and forces on belt teeth will be relatively small

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

• • Order pulley stock/timing belt/Airpel (Sean)

  • Find large (Diameter pending calcs), thin crank pulley and order, or decide to machine it (Mike)

  • Spring steel flexure analysis for compliance design (Alex)

  • Proof read report draft and add commentary (All members)

  • Start work on final report /draft 2 (Steven, et al)

  • Build test rigs and check for being in appropriate ranges (psi, temp) (Steven, Tai)

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

• • Sponsor out of town all week- no meeting was held.

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

• • After Proof of Concept presentation:

    • For compliance rollers, parallel flexures (no friction) should be used over even a linear rail (rolling friction)

    • Pulley stock could be bored out and press-fit to the rest of the puck.

Risks and Areas of Concern

• • Time constraints: we shouldn't be designing still!

Resources or Information Required but not Available

• • How to perform bending radius calcs on timing belt to check for brittle failure at -55C?

Schedule

• • Describe upcoming milestone

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • ~$885 spent (awaiting confirmation of shipping/tax amounts)

    • $33.15 on acrylic for Proof of Concept presentation prototype (Purchased 2-4-13)

    • ~$742 Boca bearings (Ordered 2-8-13)

    • ~$109 OnlineMetals (Ordered 2-8-13)

• Remainder: $2650

Progress on Report and Webpage

• • Intro. from report added to home page. Executive summary will replace it

  • CAD pictures added of newest puck designs (as of Friday)