156B Week 5

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

• • Six coil array was created and tested and was able to stir two small vials at the same time. However, it didn't behave perfectly. 

  • Continuing work on the cores, iron plates, and specifics of the coils to make it work perfectly.

  • Raspberry Pi broke, set us back a little bit on using the Pi to control the stirrer.

Accomplishments from Previous Week

• • Built 6 coil functional prototype

• • Finally have some working analysis to help us decide what size of wires and coils we want.

  • Beautiful CAD models to help with our analysis and creation.

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

• • Find exact specifications for our final coil design. - Nick, Jordan

  • Obtain Raspberry Pi and code it. - Edward, Jordan

  • Model & 3D print new version of casing - Siddarth

  • Make a 9 coil array, test to check for interference. - Everyone

  • Report first draft. - Chris and everyone

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

In person 04/26/2017

• • Housing will be handled by IKA's ergonomics/graphic department, but we should design with IKA's style in mind. Use more radii, same sizes screws, etc

    • Actions Taken: Will adjust our case designs to match the IKA style more closely, but it is less of a priority considering they will design their own case

  • Do cost estimates of the materials used in a single device. When large amounts of stuff is bought for a lot of money but we only use a little bit, how much does that little bit end up costing?

    • Actions Taken: Create a sheet with the price of each material used in the construction of our final design

  • How are we verifying magnetic field?

    • Actions Taken: Using a magnetic paper and some cheap ferrofluid to qualitatively check it, also using analysis to find some numbers.

  • We're making good progress. The good vortex created by the stirrer is the important part.

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

In Person 04/24/2017

• • Case

    • Make top plate out of plastic for insulation and bottom out of aluminum for heat sink

    • Buy extrusions in the profile needed and cut to length

  • Actions taken

    • • Printed larger case in two parts to prevent heat buildup

  • H bridges

    • Use larger h bridge to allow more current through coils

      • BD 6222 HFP h bridge from DigiKey has ~2.5 A limit at 30 V max

  • Actions taken

    • • Moving forward with more optimized coils that don't need as much current

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

• • None

Risks and Areas of Concern

• • Vial positioning becomes very important when stirring positions share coils

    • It may be impossible to precisely orient the coils in such a small volume

  • Forming the metal plates is still a bit of a concern since we don't know how exactly we're gonna do it.

Resources or Information Required but not Available

• • None

Schedule

• • 9 coil array should be completed and working to some degree by the end of the week.

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • Spent: $217.28

  • Remaining: $4782.72

Progress on Report and Webpage

• • Webpage: Same as before

  • Report: Making progress, starting to fill in final design info