156B Week 7

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

• • Final Design has been analyzed FEMAP and approved by the sponsors and all members

  • Design changes were made to the material choice of the structure.  The material has been changed to stainless steel

  • Design change made to the telescoping mechanism incorporating the use of bushings

  • Purchasing the material and stainless steel tubing for the structure

Accomplishments from Previous Week

• • Truss elements were added to the A frame in order to increase the stiffness of the structure.

  • Stainless steel tubing quotes were obtained from distributors

  • Fabricated a 1.25" bushing out of a delrin rod and press fitted to an 1" aluminum tube for testing

  • Contacted plastic distributors and bushing manufacturers about material choice and options for the bushings.

  • Solidworks model completed with new design

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

• • Pickup order of tubing and materials

  • Test the delrin bushing in a telescoping leg prototype under 890 N (200 lb)

  • Obtain quotes from potential bushing and fitting distributors and place order before the end of the week

  • Write a proposal for enlarging the budget of the project to accommodate our design

  • Present final solidworks and FEMAP models to the sponsors

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

• • Approved the FEMAP analysis and the mode frequencies that resulted

  • Approved our request for enlarging the budget of the project

  • Suggested we use plastic bushing and delrin in particular

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

• • Bushings will eliminate the galling problem all together and eliminate the need for any anodization

    • We have changed our model to incorporate bushings

  • Suggests that stainless steel tubing should be used to increase the stiffness and that it will not cause too much of a weight gain

    • We have changed the material being used to stainless steel instead of aluminum

  • Report changes to be made

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

Risks and Areas of Concern

• • Material choice of the bushings (plastic deformation, creep)

  • Delrin bushings may slip under the weight and may not pass the requirements

Resources or Information Required but not Available

Schedule

• • 5/13 - Purchase orders sent for the Stainless steel tubing from tube service and online metals (Steven)

  • 5/13 - Purchase orders sent for the threaded tube ends and the swivel feet (Tommy)

  • 5/13 - CAD model uploaded to the project website (Alex)

  • 5/13 - Load test of Leg with delrin (Tommy and Steven)

  • 5/15 - Meet with the sponsors (Group)

  • 5/15 - Material choice made for the bushings (Group)

  • 5/15 - Purchase order sent for the bushings (David))

  • 5/16 - Completed CAD model of the structure (Alex)

  • 5/16-5/17 - Pick up Packages (David)

  • 5/17 - Purchase order sent for the truss elements (Steven)

Budget (list amount spent and amount remaining)

• • Spent: $340

  • Remaining: $1160

Progress on Report and Webpage

• • Rough draft of the report submitted and reviewed with advice and amendments to be made