156B Week 7

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

• • After consulting with Tom, the team has decided to cut and fold sheet metal into the shape of the water tank for the prototype unit.

    • Sheet metal has yet to arrive

    • The seams will be likely welded closed, and the top of the tank can be left open since the acrylic plate will be above it

    • The aluminum brackets can also be replaced since the tank will occupy the space between the beams and the acrylic plate

    • As an alternative to the brackets, the acrylic plate itself can be held in place with screws inserted through the acrylic side plates

  • Besides the water tank, the containment unit for the pump and accumulator has been built and the support beams have been cut to length

  • Next step is to cut access holes into the aluminum beams to fit onto the mounting brackets and goose-neck supports

  • While testing the pump' cycle time with the system in use with the Hago mister nozzles the following was observed:

    • the pump would turn on after more than 2 minutes of the misters running, and for no more than about a second

    • as such the noise and vibrations caused by the pump were minuscule and infrequent (as suggested by instructor meeting 5/8/17 the noise factor may be a non-issue)

Accomplishments from Previous Week

• • Threaded wire has been purchased and implemented with the capacitors

    • there is a clear reduction in noise caused by the wires during testing, as compared to the single cable wires used previously

  • 0.47 uF capacitors have arrived and have been compared to the 15,000 and 10,000 uF capacitors 

    • When implemented with the converter, the 15000 and 10000 uF models reduce the initial voltage spike seen when the pump turns on to about 16 V and 17 V, respectively (although this is for a few nanoseconds in time). Both readings settled at around 12 V to 13V afterwards

    • The much smaller 0.47 uF model did not filter the spike well at all, since a reading of around 32 V was observed at the pump turning on (the small capacitance is best used after the converter to filter the fans directly, since they only have the 12 V to draw from and are usually not turned on and off as frequently)

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

• • Cut, fold, and weld the sheet metal water tank (Cristobal, Oscar)

  • Cut access holes in the aluminum beams to fit into the mounting brackets, and to allow tubes and wires to run through them (Chota, Erasmo)

  • Final Report revisions continued (team) 

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

• • Water inlet nozzle used to fill the tank should be under the tank and out of the way of the cup holders (meeting 5/11/17)

  • The space between the pump and accumulator can be reduced (meeting 5/11/17)

    • While the tank is being cut from the sheet metal an access hole can be cut at the bottom plate to fit the one-way nozzle

    • The top of the tank may be left open and the acrylic plate or a lid may be used to cover it. This is an alternative to having the tank be completely enclosed to allow air to escape while filling

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

• • The idea to use a metal water tank for the prototype was provided by professor Tustaniwskyj (meeting 5/8/17)

  • As stated Overview of analysis section above, the dB noise measurement may not be an issue to be considered

  • A user and assembly manual should be made as deliverable items ( meeting 5/8/17)

    • By working on the Final Report, the team should essentially have these two manuals written and ready to be made into a booklet if needed

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

• • NA

Risks and Areas of Concern

• • The cost of the system is still an issue since although the final product is intended to be rotomolded, the mehods  currently used for the prototype's assembly is already at the $150 goal

Resources or Information Required but not Available

• • The team is still looking into how many G forces a cart is allowed to handle on average while driving to match how much the mister system can be subjected to 

Schedule

• • Describe upcoming milestone 

Budget (list amount spent and amount remaining)

• • Budget Limit: $1,800.00

  • Total spent as of 5/14/17: $319.21

  • Remaining: $1480.79

Progress on Report and Webpage

• • Corrections have been noted from instructor meeting (5/8/17) and are underway

  • Once the misting system has been completely mounted on the cart, the images on the webpage can be updated