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\uD83D\uDC65 Participants

\uD83E\uDD45 Goals

...

  • Discuss SRR takeaways and identify key action items to move forward

  • Discuss PDR and CDR objectives and timeline

  • Narrow down the general architectures we are pursuing for the next-gen car

  • Discuss Daybreak Progress

\uD83D\uDDE3 Discussion topics

Item

Notes

Announcements

Dynamics:

Aeroshell:

Body:

Emech:

What is something you struggled with this week? What is something you are proud of this week?

SRR Key Takeaways/Next Steps

  • Overall

    • Ideas for reviewing drawings and structure for estimating weights

    • Get reasoning for 3 wheel by PDR

  • Suspension

    • Not being scared of aluminum welding and using that as a way to push ourselves

    • Quantify with just reasoning our parameters like 60-40 or FOS

  • Steering

    • Look further into gearbox design as the issues we were maybe afraid of aren’t as big of a thing

    • Look into tunability

  • Unsprung

    • Figure out brake disks

    • Tolerancing of bearings

Overall

  • we need to define how we are going to do reference points on the mold, and confirm that the knowledge is transferred

Aerodynamics

  • We need to solidify the plan for splitting up work and creating different parts of the shell(nose, tail, how to we avoid it messing up the overall geometrey)

  • Talk about roll cage in an intersystem meeting, because thats the next big thing that defines what we do

Composites

  • Figure out design of windshield with respect to the polycarb and what materials we should use

  • LOTS of wesley notes, not worth putting all in this spot since its lot of smaller specific notes

  • resin infusion is a risk and will cost a lot of money (vacuum)

  • consider having aeroshell PDR at the same time as dynamics and frame CDR

  • Be more thoughtful/less arbitrary with goals (i.e. goals were good, but have them bounded better, and be able to directly measure/compare them in the future

  • Really really review composites plan to ensure we can make good progress while reaching our key frame goals

  • Be more thoughtful in ergo design, think more about possible situations/applications (minimize oversight)

  • Difference between making a part that would be cool, and making a part that is practical and effective (i.e. carbon fiber steering wheel vs fiber glass steering wheel)

  • Rethink whether we really need so much of cooling, vibration dampening, etc

  • Have a good testing and simulation plan - know the basics.

  • Do composite testing but only test for your expected loading/impacts. Wastes time

  • Add FOS to only few parts and then design other parts to handle extreme cases

  • Shield all HV cables - probably a source of most EMF interference

  • properly fuse all battery connections

  • Match mechanical loading of rest of the car in terms of FOS/what we can see during transport

  • Base cooling off of RMS current

Workday Review

Next Workday Plan

Daybreak Progress

  • Ansys whitelist is closed. If your members did not fill it out, they will not be able to install Ansys.

  • The frame is detached from the shell. Thank you to everyone who helped out!

    • Next steps are refilling and rebleeding the brakes. This is to test the motor and try to recreate the conditions that caused controls to fault at comp

      • TLDR: Controls system faults when we accelerate too fast or go above a certain max speed. Unsure what the issue is, perhaps motor controller config

  • ClickUp use has not been satisfactory

    • Don’t just fill out ClickUp because we tell you to

    • It is a tool that will make your life easier. Once it is up-to-date it takes minimal effort to maintain it so long as you do it constantly

    • This is also a way for me to keep track of everyone’s progress. I don’t only want to have progress checks during meetings, but it also isn’t sustainable for me to text each one of you to ask about progress

    • Don’t want to micromanage but it seems we have this reminder every week

    • Ideally in the future we should just be able to pull up ClickUp for these meetings and ask about progress

  • Machine Shop Certification Sign Up Genius: https://www.signupgenius.com/go/805054BADA628A4FB6-52221970-lhrmachine#/

  • Reminder: new members should be given homework each week to develop their knowledge of their system and their engineering skills

    • Two parts:

      • Theoretical learning resource: youtube video, textbook chapter, etc

      • Engineering skill exercise: CAD exercise, hand-calcs, etc

    • They will need to do both of these things in their starter projects, so we should build up a habit

  • Philip’s Concerns

    • Worried members may be getting introduced to work without a sufficient understanding of the theory behind their system

    • Make sure to check in with members about if they are satisfied with the task given to them, if they know what to do, if they feel lost

      • I spoke to several members on workday who expressed confusion at what they were actually supposed to be achieving

PDR and CDR

Feedback on these dates:

PDR: Saturday, January 18, 2025

  • Aeroshell is planning to have the molds sent out by this time

  • Does not want to change the bottom shell significantly

  • Have something relatively close by PDR

CDR: Sunday, February 23, 2025

Dynamics:

Aeroshell:

Body:

Emech:

SRR Key Takeaways

https://cloud.wikis.utexas.edu/wiki/x/LwdtD

Aeroshell SRR Takeaways

Body SRR Takeaways

https://cloud.wikis.utexas.edu/wiki/x/i4V4D

Action Items

  •  Setting suspension hardpoints
  •  Determining ride frequency, spring rate
  •  Identify operating conditions
  •  Upright bearing selection
  •  Brake caliper selection
  •  Shock absorber selection
  •  Gather data on steering radii sensitivity
  •  Completion of composite testing plans with timelines and purchasing sheets
  •  Have roll cage meeting with body
  •  Have array size meeting with power gen
  •  Suspension hardpoint widths for Dynamics
  •  Identify driver position
  •  Have roll cage meeting with aeroshell
  •  Create testing plan to determine average and max pedal force
  •  Ergo material decision matrices
  •  Identify nextgen battery box dimensions
  •  Establish plan for cooling calcs and testing/measurements
  •  Set RMS Current value
  •  Cell characterization (Dr Subramanian's lab)
  •  Research automotive grade positivley-latching connectors, duc

Architecture

Dependencies

Pros

Cons

External Suspension

  • Bottom shell

  • Narrows the front surface area of shell

  • Un-constrains outboard dynamics

  • Accessibility

  • Allows for a larger track width

  • Attaching wheel covers and suspension aero covers

  • Increases turbulence

  • Control arms under higher loads (increased bending moment)

Internal Suspension

  • Has been done before

  • No need for wheel covers

  • Minimal turbulence

  • Need for wheel cutouts and access panels

  • Dynamic stability and packaging (especially with 3 wheel car)

Driver placement biased towards front

  • Canopy placement

  • Top shell profile

  • Array placement

  • Roll cage location

  • Battery location

  • Easier to guarantee dynamic stability

Driver placement biased towards rear

  • Canopy placement

  • Top shell profile

  • Array placement

  • Roll cage location

  • Battery location

  • Reduced shading on array

  • Allows for more optimal array cooling

  • Canopy shape matters slightly less

  • Simpler manufacturing for top shell (flat top shell)

  • More difficult to guarantee dynamic stability

Single part top shell

Two part top shell

Multi level frame

  • Not shit :)

  • Makes it easier for favorable dynamics

Last year’s frame

Single Battery

Frame - bounding box, potential locations, mounting points

Shell - Where can the battery be removed from

Split Battery

Frame - bounding box, potential locations, mounting points

Shell - Where can the battery be removed from

Size

Frame - bounding boxes

Regs - number of cells

Ducts

Aeroshell - intake/exhaust holes

Frame - Routing

Draw external air, better cooling

might not be within regs

Heat Pipe Cooling

Aeroshell - air intake/exhaust

Battery

Frame - Space

Higher cooling efficiency than air, uniform cooling, less power allocation, won’t have to worry about positive/negative pressure in battery

regs say we HAVE to have airflow within battery box, need to clarify if heat pipes are an actual substitute. Also this level of cooling might not even be necessary depending on cells

Airflow Cooling

Aeroshell - air intake/exhaust

Battery

Frame - Space, duct routing

Previous design, simpler to implement, less testing/calcs needed to design/verify

more fans → more power needed, worse cooling efficiency and nonuniform. Nose intake might not be within regs

Dynamics:

Aeroshell:

Body:

Emech:

Weekly Updates

  • Need to do more daybreak work

  • Might need to redo/rethink some of the cooling solution due to new regs

  • Adjust module mounting and bus bar location since we are removing load from midpanel

Daybreak Progress

  • Extending daybreak controls arms by 2

  • BPS and Contactor layout complete

  • Main enclosure complete, need to add mounting locks and roller wheel

  • Dashboard layout and connections finalized - controls has v1 done, waiting for review and order

  • Opened up battery and identified broken modules. Prat and Frank will have ppl go up and start fixing it to start motor testing.

  • Driver cooling (on dashboard) design finished

Questions people want to ask

What do you need from me this week?

✅ Action items

  •  Philip Bortolotti go to dynamics meeting to discuss sensors
  •  Evan Zhang create preliminary steering linkage support by , getting help from Noah Hickmanfor weldments
  •  Kayla Lee have new suspension geometry for Daybreak by Sunday
  •  Pratyush Patra and Frank Li go up to pickle and repair battery
  •  Parthiv Shah Have battery ready to review by Wednesday or Thursday
  •  Have composites testing plans done this workday Advait Joshi
  •  HAVE A DECISION FOR FRONT OR REAR BIASED DRIVER POSITION BY 10/21

⤴ Decisions