156B Week 7

What has been done in the past week

• Finished building Hyatt Regency Models

• Finalized the designs of the Center of Mass Design Challenge

  • Sent designs to machine shop to be made out of a dense foam material

• Ordered/manufactured different connections to be tested for truss design challenge

  • Mocked up knex part on CAD and laser cut foam core

  • 3D printed hubs

    • Got price estimate on injection molding these hubs = too expensive

  • Foam balls

  • Copper ring caps

• Revised CAD for reaction box

• Finalized cross sectional shapes and material choice for buckling demonstration tool

• Designed and ordered materials for acceleration demonstration tool

• Ordered materials for Vector Box Demonstration tool

Feedback from last meeting with sponsor

Reaction Box

• Wants hinge that doesn’t stop linear sliding

  • Can make one instead of buying one

  • Doesn’t need to be apart of the box

COM Challenge

• Lasercut wood?

• Materials that are able to be lasercut:

  • https://wiki.atxhs.org/wiki/Laser_Cutter_Materials#:~:text=The%20laser%20can%20cut%20or,stone%2C%20tile%2C%20and%20glass

  • Thickest is 1/2inch

• Konex printer is too expensive and time consuming

Truss Challenge

• Lasercut foam core / dense foam

• It’s okay if there’s discrepancy between the calculations and actual implementation

  • e.g: if it breaks at the joints

• Can try 3D printing just to test it out

• Good to at least try different materials out

3D Moment about a Point

• Wants spring at the wall

• Mount flange onto a spring

• It’s okay if this isn’t a priority / doesn’t get done

Buckling demo tool

• Different cross sections

• 10:1 ratio

• Brainstorm materials

  • Flexible filament? Ninjaflex

Ball with string

• To show normal and tangential acceleration

• Smaller than a tennis ball

• Secure so that it doesn’t fly away

• Can buy one

  • Send link to Qi for purchasing instead of coming out of our budget

Presentation

• When kit is finished, we want to focus our presentation on the kit as a whole instead of individual components

• Give a pitch (like Sharktank)

• “Why do you want this expansion pack”

What is the next step of your project

• Sand, prime, and paint the Center of Mass shapes

• Create assignment prompts for design challenges and 3D moment about an axis model

• Truss design challenge

  • Test out different connections & decide on best material

  • Decide on challenge parameters

    • Material cost and environmental score

    • Design space (length, load value, load placement)

    • Number of materials provided

  • Create supports (fixed and pinned) -- wood?

• 2D moment demo tool

  • Figuring out how to support peg board

  • Ordering small jewelry bags to hold masses and zip ties

• Finish reaction box

• 3D print buckling demonstration tool

• Start manufacturing motorized acceleration demonstration tool

• Start designing vector box demo parts in solidworks and autocad based around purchased parts

• Update of First Draft of Report Due Friday

Questions for Sponsor/Instructor

• N/A