156B Week 4

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

• • Removed stand bracket, string connection added to limit angle of legs

  • 3 3D printing pieces: replacement stand bracket base, bag to stand connector, and stand bracket connector

    • First printing material was brittle, used another printing material

  • Replacement stand bracket has square cross section  --> no rotating

  • Current issue of handle tilting since its no longer connected directly to the bag

  • Bag no longer retains shape

Accomplishments from Previous Week

• • Smoother leg extension movement with square replacement stand bracket

  • Folded the bag and stand system into 1/3 original size --> 36 cm after folded

  • Use tent pole leg elastic string connections to make assembly easier

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

• • Figure out a way to improve the rigidity of the bag

    • Add another tent pole stand bracket? WiIl confer with sponsor

    • Then we would go over our limit of 3 assembled pieces

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

• • Upcoming Meeting on Saturday 2/1/20

  • Previous meeting notes from Skype meeting on 1/21/20

  • -Introduced current prototype to sponsor

    • -Sponsor said to make foldable stand bracket instead of designing new handle extension mechanism

    • -We mentioned the possibility of decreasing the size to 1/3 of original size

    • - Sponsor asked how easy would it be for the customer to assemble?

    • -Then we showed the next plan of using tent pole legs to replace stand bracket and legs

    • -Sponsor asked if it would be strong enough?

    • -It should be strong enough since on top of being easy to assemble, it would have enough strength because there is no tensile force on the legs/stand bracket

    • -Sponsor said our project can just be a proof of concept/design prototype instead of a well-fabricated final product prototype

    • -Is there a possibility of removing the stand? Hasn’t been tested yet.

    • -Sponsor suggested we could try to remove the stand, rise in manufacturing cost can be compensated by reduction in shipping cost.

    • -Manufacturing cost of tent post could be only $2. Removing stand also reduces manufacturing cost

    • -TDCA never replied about handle information

    • -Sponsor asked us to forward him the info

    •             -Including: wear test, handle and 3D model, stand bracket specs)

    • -Email about budget form

    •             -Will send later today

    • -Plan for upcoming week: Build tent pole leg prototype feature, finish by next week

    • -For next meeting: If prototype finished, meet downtown. If not, Skype meeting.

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

• • Meeting in person on 1/23/19

    •  

    • -We don’t know how long this cheap elastic will last

    •             -may try to use stronger elastic that lasts 3-5 years

    •             -currently using very cheap one

    • -modified previous design connector feature with a screw added

    •             -connects stand bracket parts

    •             -will try to manufacture in the machine shop

    •             -if we can’t do that then we will 3D print it

    • -trying to have just 1 connector on the stand bracket

    •             -get rid of current restraining piece

    • -will the legs be able to hold the clubs

    •             -will weight of clubs make the legs lose their cylindrical shape?

    •             -a long length of tent pole legs will bend over tent

    •             -short length will not bend

    • -current tent pole legs diameter are smaller than original legs

    •             -larger diameter = stronger legs

    • -need to make sure tent poles legs are strong

    •             -make small dent in tent pole leg to lessen twisting of legs

    •             -manufactured dent would be stronger

    •             -but consumer might think it’s a defect?

    • -don’t want legs to be exactly cylindrical to avoid twisting

    •             -make tent pole ends slightly cylindrical

    •             -might make it harder for consumer to put it together?

    •             -rubber bands provide constant force

    •             -might be confusing to consumer, could take them longer

    • -we have to think about this from the worst case

    •             -anybody should be able to assemble this

    • -next time: we will show fabricated connector pieces

    • -luggage telescoping legs

    •             -after 3-5 years the legs would not be sliding in

    • -do these golf bags have warranty?

    • -About $40 to sell but cost to manufacture is ~$10-15

    • -should be able to conceptually test the tent pole legs & telescoping by next week

    • -will test how intuitive it is to make this

    • -need to look into glitches: user experience, strength (structure)

    •             -verify the manufacturing perspective

    • -should we ask golfers to test bag? Ask sponsor is this is necessary

    •             -user test will extend scope to validate/justify design = robust

    • -very important to isolate what can fail

    •  

    • -TA suggestion: original goal = decrease size

    •             -not exactly user experience, more of an assembling experience

    •             -focus on the goal

    •             -goal can be dynamic, seen/unseen consequences

    • -TA suggestion: why did sponsor like the suitcase handle idea

    •             -maybe bc they like the feeling of handle going up and down

    •             -doesn’t mean need that exact strictly design, just like that feeling

    •             -ie. clicking together of tent pole legs is what use likes

    •             -think about what customer wants

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

Risks and Areas of Concern

• • Poor user experience, bag feels unstable when you set it up 

  • Using strings to limit leg angle, this is a short-term solution

    • May get tangled/break easily

  • Currently using some 3D printed pieces, we are unsure of their strength/wear

  • Unsure of how long elastic strings inside tent poles will last

    • Elastic toughens over time, may become brittle/rigid

    • Need to find better quality of elastic

Resources or Information Required but not Available

• • CAD Model for handle

  • CAD model for all components

  • How do they do wear tests and strength tests? 

  • List of engineering standards related to this system

    • We have received reply from sponsor or company engineers 

Schedule

• • Brainstorm ideas for new stand bracket system that is foldable

Budget (list amount spent and amount remaining)

• $140 spent at machine shop

• $42 telescoping replacement extension

• $34 small tent pole legs

• $40 large tent pole legs

  • $15 elastic string

• $2729 remaining

Progress on Report and Webpage

• • Continuing to update weekly progress reports

• Update draft of report with Engineering Standards section