156B Week 4

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

• Milling and welding practices learned being applied.

• Final design of trike with precise measurements for titanium components completed.

• Measurements of titanium tubing sent to titanium supplier.

• Lamination theory and analysis being applied for carbon base tube.

• Construction of mandrel pending carbon tube length analysis

Accomplishments from Previous Week

• Seat, arm, and foot geometries for Lance acquired and applied to final design. (Nicolas & Angelica)

• Redesigned seats for titanium configuration. (Sean & Angelica)

• Begun working lamination theory on carbon base tube to determine configuration and specs for mandrel construction. (Ved & Nicholas)

• Begun fabrication of stress areas of titanium components. (Sam, Sean, & Angelica)

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

• Fabricate 2 critical stress areas from titanium. (Sam, Sean, & Angelica)

• Finish mandrel construction for carbon base tube. (Ved & Nicolas)

• Decide between rolling and molding carbon around mandrel, as well as tapering, etc. (Ved & Sean)

• Decide on pushbar design to apply to the trike. (Sam & Angelica)

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

• Learned that bending titanium tubes is possible if the tubes are 7/8" diameter. Seat frames likely to be made of titanium now to eliminate extra interface between aluminum and titanium. (1/24/17 in person)

• Received information on how to apply lamination theory for carbon base tube to model FEA in Solidworks. (1/24/17 in person)

• Molding carbon around mandrel is a viable option and has it's pros and cons compared to rolling carbon around mandrel. (1/24/17 in person)

• Given links to all attachments to the trike. This improves modeling parameters to minimize wasted space in design. (1/24/17)

• Recommended different configurations on pushbar attachment. (1/24/17 in person)

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

• Professor prefers welding be done at ucsd.

• Be careful of mandrel stress concentrations,be wary of higher tolerance required if threading, . Keying?

• Professor asked “can we bend __ inch diameter ok?” Upper campus machine shop could be a solution.

• Welding aluminium is difficult, and warping is an issue perhaps. 

• For seats, thin wall stainless steel fatigues less then aluminum and would be better for welding but harder to bend.

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

• N/A

Risks and Areas of Concern

• Availability of machine shop for milling/welding titanium.

Resources or Information Required but not Available

• N/A

Schedule

Adjusted Gantt Chart format to highlight Action Items, prototyping, testing, manufacturing stages (Nicolas)

Budget (list amount spent and amount remaining)

• Spent: $0.00

• Remaining: $ 9995.70

Progress on Report and Webpage

• Week 4 progress report complete.

• Select sections of report to be uploaded Friday 2/3 by midnight.

• Home page under construction.