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\uD83D\uDC65 Participants

\uD83E\uDD45 Goals

  • Discuss pros/cons and feasibility of a 3 vs. 4 wheel car

  • Budget review

  • Timeline and dependency charts

...

3 vs. 4 Wheel Car

Pros

Cons

Leaning towards

General

Aeroshell

3 wheel:

  • slimmer/lighter shell

4 wheel:

  • we’ve already manufactured and designed this

3 wheel:

  • may tip?

  • we don’t know as much about designing a 3 wheel

4 wheel:

  • much bigger

3 wheel

  • better for aeroshell

  • more to learn

Fergo/Structures

3 wheel:

  • Lighter frame, less tubing potentially

4 wheel:

  • Simpler, more symmetrical design (also more weight balanced)

3 wheel:

  • More complex design requirements, could take longer to sim and validate

  • Center of gravity is a larger concern

    • placement of large components

4 wheel:

  • Potentially more weight

Dynamics

3 wheel:

  • Easy implementation of trailing arm in rear

  • Able to have blended regen braking → power savings

  • Symmetrical braking, no risk of unevenness

  • Less overall parts to manufacture

4 wheel:

  • We have experience in it

  • More stable

3 wheel:

  • More risk of tipping during cornering

  • Lower overall dynamic stability

  • Less stiffness in roll due to fewer wheels

  • Rear wheel blowout could lead the car to spin out

4 wheel:

  • Heavier

  • More difficult to balance braking

  • Uneven CG due to motor being biased

Emech

3 Wheel:

  • Smaller body/frame so potentially smaller wire lengths

4 Wheel:

  • more access points for fresh air

3 Wheel:

  • less space to mount components, especially with a split battery and requiring more power distribution hardware

  • might not work with current topology of SOM controllers

4 Wheel:

No preference - will work around either

Budget

Refer to Solar Budget Spreadsheet

Notes:

  • Daybreak: electrical components, suspension components

  • Less of this money will be going into integration (for this year), so use money to stock up on tooling, stock, and other supplies

    • machine tooling

    • dremels

    • etc.

  • Goal is to start manufacturing this year, so look through old budget and basically cut it in half

  • Whole point is to convince other teams that we need the money, so make sure to explain your reasoning and keep it as solid as possible

Scope of Modifications to Daybreak for FSGP 2025

Plans

Timing

General

Aeroshell

Find screws to fix canopy latch

  • no more than one workday

Look at more secure canopy hinge

  • control side to side movement more

Fix shell to frame

Install top-shell tilting mechanism

Widen wheel cutouts

  • make sure area between wheel access panels and wheel cutouts is strong enough

*we made need more but I havent looked at the car, these 2 are the only ones I’ve heard tho

Latch

  • no more than one workday

Hinge

  • 2 weeks?

  • possibly a freshman project, but I already know a lot more about hinging than anyone else so itll take a decent time for them to catch up.

Tilting

  • month?

Wheel cutouts

  • no more than one workday

Fergo/Structures

Frame

  • Spot weld areas that are not fully welded (behind roll cage foam)

    • New member welding practice

  • Repaint

    • Teach new members how to use spray gun

  • Driver shields

    • Maybe use a more rigid material like sheet metal

Ergo

  • Brakes

    • Potential design change to pedal box to accomodate for brake light

    • Rebleed brakes

  • Communications

    • Make better plan for communications

  • Minor fixes to seat

  • Steering wheel

    • Remake the steering wheel to accomodate for buttons

    • Remake the grip

  • Ballast Box

    • Fix latch

Spot Welding

  • 1-2 days

Painting

  • 1 day to paint

Driver shield

  • 1 week

Brake Lights

  • Design change - 2-3 weeks; May be hard for new member project

Bleeding Brakes

  • Possibly may have to reroute brakes as well if rusting is worse than expected - 2 day; New member project

Communications

  • Work with data acq and purchase depending on changes of plan - 1 month; New member project

Steering wheel

  • Work with electromechanical to mount buttons and design/manufacture - 3 weeks; can be a new member project

Ballast Box

  • Easy fix to ballast box latch - 1 week; new member project with manufacturing

Dynamics

  • Steering revision

    • Supports at the ends of the rack extenders to counteract bending forces from the wheel turning (pillow blocks with linear bearings)

    • Extra constraint of the intermediate steering shaft

    • Correct length tie rods

  • New Control Arms

    • Longer to increase suspension travel before bottoming out shock

    • Larger

    • Spherical bearings at upright attachment

    • Possibly rotate orientation of inboard rod-ends to align load pathing with structure of wishbones

  • New Shock Extenders

    • Will be a result of the control arm changes

  • Steering Revision

    • part acquisition and attachment will take 2 weeks - can be done by new member

    • design, material acquisition, and fabrication will take 2 weeks - can be done by new member

    • Design and fabrication will take 1 week - can be done by new member

  • New Wishbones

    • Design will likely take several weeks of iteration

    • Intend for a new member to do this

    • Machining will vary depending on approach

    • Tubular wishbones may be shorter, solid wishbones will be longer

    • If a CNC is needed, machining softjaws and running the CNC will extend the time needed

    • Overall this is a full-semester project

  • New Shock Extenders

    • Will likely take around a week to redesign then machine

Emech

  • New battery enclosure (potentially slightly different BPS)

    • try to keep cooling as similar as possible

    • roughly same bounding box

    • actually modular so modules can be swapped

    • will require flat layups

    • Finished battery pack by end of februrary

  • New enclosures

    • water/splash resistant

    • some form of quick release mounting (instead of directly attaching to pipe clamps or frame tabs)

      • new members

    • panel mount connections

      • new members

    • 2-3 weeks to design

    • 2-3 weeks for manufacturing if printing

  • Few minor changes to cooling for new battery/interfences with additions to the car

    • same design, maybe changing dimensions or positioning slightly

  • Completely new wiring

    • 3 workdays

      • can be reduced with more hands and work doing week

  • Combine controls hardware into dashboard

    • 1-2 workdays once controls hardware and other hardware positioning finalized

  • Data qa

    • radio mounting

    • leader board mounting

    • sensor mounting/routing/shielding

  • Battery

    • End of Feb

  • Enclosure latching

    • 4-5 workdays

      • designing, prototyping, testing

      • new member project

  • New Enclosures

    • 4-5 workdays

      • depends on how many have to be made and how long 3d printing will take

  • New Wiring

    • 3-4 workdays

  • All of these have pre req decisions that need to be made from both divisions so they can’t be started until a lot is finalized

Timeline

Refer to 2024 -2026 Timeline and Dependency Charts Planning

✅ Action items

  •  Everyone have budget draft fully prepared by EOD monday

⤴ Decisions