156B Week 2

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

• • We have some new prototype ideas

    • Tent pole legs (connecting pieces together with string inside)

    • Telescoping legs (like suitcase handle)

Accomplishments from Previous Week

• • Built a new stand bracket prototype

    • 2 version of it

      • One version is 2 separate pieces

      • Another version has hinge that allows bracket to fold in half

    • Is fairly strong, needs more testing

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

• • Built tent pole prototype

    • Test this prototype

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

• • -Says its great how much smaller its become so far, halfway smaller

    • -current prototype is a proof of concept

    • -can deassemble top of legs also to reach a minimal size, squeeze the cloth bag

    • -trade-off: consumer doesn’t want to build the product, as long as legs are easy to snap

    • -stand bracket is most difficult part

    •             -need to snap in?

    •             -telescoping legs and stand bracket?

    •             -we would want to do telescoping legs

    •                         -telescoping wobbles, more expensive to manufacture

    •                         -little spring connections in between, each telescoping leg wobbles

    •             -make legs similar to ski poles

    •                         -2 parts that snap together with string

    • -need a larger movable distance for legs to push out

    • -3D model of top part? Need several versions of it

    •             -we need their current 3D model of the top from TDCA

    •             -not smooth surfaces so we don’t know dimensions etc

    • -there is no ideal angle for golf bag, +/- 60 degrees

    • -can use tent pole legs for prototype?

    • -$13 shipping to $5-6 use these numbers?

    • -show different options of top part, give pros/cons

    • -handle should be comfortable for user to hold

    •             -steel wires should be hidden

    •             -if steel wire gets bent then bag is useless, maybe plastic protection around it?

    •             -top part needs to get larger so wires/handle mechanism can be hidden

    • -we accomplished exactly what needs to be done, now we need to focus on improving it

    • -how long will this bag work? If handle stops working then consumer will send bag back

    • -redesign thin stand bracket part so it is constraining AND assembly piece

    • -analyze load distribution on stand bracket

    • -should focus on connector piece on stand bracket, spring steel hard to cut

    •             -is there a lighter option for small bags? Big bags need the strength bc more weight

    • -where should we cut on the spring steel?

    •             -when its cut, 1 part à 2 parts changes max stress

    •  

    • -telescoping legs:

    • -pros: can make it extra smaller, size is only the top portion, can try prototyping with      tent legs

    • -cons: need very accurate precision manufacturing, more expensive

    • -screw legs:

    •             -pros: easier to manufacture, cheap

    •             -cons: limited to a bag being half size as smallest size

    • -tent leg type

    •             -pros: can decrease to a third of the size instead of a half

    •             -cons: stress concentration will coincide with connections à problems/unstable

    •            

    •  

    • -for reference: warehouse to the consumer online $13, cut it by half then ~$6-7

    •  

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

• • -Come up with multiple designs, write the different pros and cons

    • -make a PEU chart to compare different pros and cons

    • -new designs for different features

    •             -in early stages, should have completely different designs

    •             -sponsor chose this design bc its easy to use, not complicated

    •             -in spring design, that had an extra movement that was removed

    • -should compare different components and features

    • -should communicate with sponsor what he wants compared to what we have

    • -manufacturers want specific features on bag, but need to convince sponsor

    •             -need to tell sponsor why this is good

    •             -need to show sponsor pros and cons by comparing to other options, this is “best”

    • -we have constraints of time etc.

    • -sponsor doesn’t know exactly what they want

    •             -need to tell them pros and cons

    •             -diff designs have trade-offs, good on this but bad on that

    • -adjust design based on their need and our constraint

    • -think from their perspective, what do they care about the most

    • -give different designs for each feature

    •             -for each part compare the engineering itself, the cost, etc

    •             -rigorously explain why we chose the different features that we did

    • -if we modify we have to explain why we make the modifications we make

    • -prototype is for us to understand the pros and cons

    •             -no use prototypeing is too $$$ or is 10 week lead time

    •             -if cant prototyping then don’t

    •             -if can prototype then decide what is needed to fix

    •                         -ie. the feel, try small amounts of different cloths

    • -explore diff options for each feature

    •             -very exhaustive, do to our best ability

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

Risks and Areas of Concern

• • Unsure of strength of tent pole legs

  • We predict the telescoping legs will be wobbly and unstable as well

Resources or Information Required but not Available

Schedule

• Draft of report with Impact on Society and Professional Responsibility sections

• Complete tent pole legs prototype

• Week after, work on telescoping legs

Budget (list amount spent and amount remaining)

• • $140 spent at machine shop

  • $42 telescoping replacement extension

  • $34 tent pole legs

Progress on Report and Webpage

• • First draft of report due this Friday