Design Table

Regs

Ref. 2024 ASC

Meeting Notes - Oct 7 2024

• Communication & transparency amongst teams

• Decision Making Process

  • Design Matrix, Pros & Cons, FMEA, etc.

• Design Intent for MS16

• Reminder MS15.5 Regs releases, if changes are planned → details and estimated cost by Saturday

General

• Design Intent MS15: Solar car that can drive, pass scutineering, and get to comp (minimal inefficiency, perform well)

• Design Intent MS16: Improve reliability (HOW?), be able to race in ASC 2026, 60-80 laps at FSGP

  • Improved performance, reduce inefficiency, make ~100kg lighter

  • First address immediate design intent than invest into the “Nice to Have”

• Why statements

Variable Recap

Occupant Cell

• Front plane to Hip Node variable Discussion

  • Airfoil shape, 5g Front impact considerations, solar array area optimization

Suspension

• FSU & RSU Space claimed, starting nodal for linkage skeleton diagram

Steering

• Pending on Nodal, may relocate driver

Brakes

• Front Wall/ Floor monuted, looking into custom pedal complexity

Exteriors

• Flat sides vs tear drop top view

• Canopy width → dependent to rollcage width

• Canopy Length → ideal 6x Canopy Height, Canopy Height = (Hip-to-head)cos25 - Aerobody Height + Clearance

• Playing around with aerobody width to enable 6m^2 of array area

Battery

• Easier to remove from car vs Easier to access within car

  • Larger contributor to goal is reduced weight and ability to get closer to the box

• Hardware Box added in space claim as the separate box greatly improves electrical accessibility

• Location dependent on CG calc (waiting on approximation of rollcage mass)

• Work In Progress Design Matrix for Battery location

  • SharePoint PowerPoint Presentation: https://uofwaterloo-my.sharepoint.com/:p:/g/personal/s56kim_uwaterloo_ca/ETd178EVoUFOuKsiE9cwnA8BwzVGgWqd-FrLMp7qdtK5VQ?e=KIupxs

Meeting Notes - Sept 28 2024

• Internals: driver selection 5' 9”

• Dynamics: Double wishbone & ackerman steering

• Battery: 1 enclosure with one smaller for HW

• Exteriors: potential to change angle of attack, dependent of system location

General

• Locked: Origin Location, Axis direction

  Open

  

• Will be making Master Assemblies on Bild this week

• Still waiting on 2025 & 2026 regs

• Mass of the Car + Driver is a strict 350kg* (revised oct 7)

  • Average mass of the FSGP top 10: 302.2kg

  • Average mass of ASC teams: 290.17kg

  • Average mass of ASC teams with >1000mile: 272.92kg

Occupant Cell:

• Still discussing location of driver wrt to front wheel

• Why move the driver forward?

  • Since the roof panel is narrower at the front of the car & the canopy takes away from precious array area, to optimize solar array area the goal is to move the canopy further towards the front of the car

  • Considerations to egress direction change ongoing (out the top or no change)

• Option #1: no change (Driver hips = 1.25m from front wheel)

  • Pedal compartment unaffected by FSU hardpoints

Open

• Option #2: Move slightly (Driver Hips < 1.2m from front wheel)

  • Pedal compartment within FSU hardpoints, creating tight working space during assembly & tuning with tight packing for dynamics systems

• Option #3: Rivian is awesome (driver hips < 1m from front wheel)

  • Rivian Reference:

  • Can allow for much easier accessibility to the battery box with a side access panel and rails to easily remove enclosure for maintenance

  • Drivers feet in line with front “axle”, very tightly packed front compartment during assembly

  • Can introduce significant weight to the car

Exteriors:

• angle of attack? nose compartment free game

• Canopy elongation for better aero performance (provide ref.)

• Main design constraint for space is solar area & tail cantilever

Battery

• Referencing MS15 enclosure dimensions

• refer to rivian concept

Suspension:

• 100% double wishbone

• Current suspension dimensions are in line with jens referral

  • @Richard Wang @Winters Xia Please provide sources

• Created parametric hardpoint frame

  • Potential to reinvest into upside down trapezoid hardpoint config

• RSU no architectural changes expect maybe a bellcrank, pending

  • Action Item: Proper dimensions for next space claim

Steering

• Due to decision to go ackerman & looking into moving the driver forward, the steering linkage is to be above FSU

• Rough nodal to be devised for next space claim to accurately determine allocated volume

• Over-exaggeration of tire angles to prevent interference

Brakes:

• ^ see occupant notes

Action Items for next space claim

• Track Lock at 0.85m

• Battery box location & hardpoint mapping

• Finalize general location for dynamics hardpoints

Space Claim V2

Legend: purple = wheels, green = suspension, grey = steering, red = battery

Meeting Notes - Sept 17 2024

• Avoiding drastic changes from MS15 to promote iterative improvements, build off existing knowledge base, and use MS15 as relevant inspiration for design

• Dynamics takes priority as vehicle performance & design is greatly impacted by dynamic systems; exteriors is critical to vehicle efficiency

• Space Claim System Priority List: Wheels, Suspension, motor, steering, battery, chassis, interiors, brakes, exteriors (consolidate with hardware whenever possible)

• Compare and contrast to wsc regs

• Mostly locked locations before reading week - Oct 14, revise in accordance with regs - around End of October

General

• CAD Origin and XYZ directions

  • Master Assembly origin

     

  • If axis direction isn’t default, create a template New Part file on Bild

  • Axis direction is up to dynamics for calcs preference

• Metric/ Imperial

  • Conclusion: Overall design in metric, critical fasteners and holes imperial only

• Overall Car Mass → Look into the weight of competitors from ASC2024

  • Average for: SOVs, SOVs that qualified, SOVs that did well in FSGP & ASC

Occupant Cell

• Driver height maximum discussion as it also leads into aerodynamic drag

  • if driver height reduced, aerodynamic performance optimized

  • if driver height increased, more people can drive

Suspension & Motor

• Motor controller Space Claim

  • Requires airflow, 100% waterproof (not in the path of any water ingress or perfectly sealed), less then 3ft from motor, accessible when roof is up

• parking brake opposite side of motor

• Rear suspension: very similar to MS15

Steering

• targeting ackerman steering, therefore volume in front of the upright is free game

Battery Structures

• Battery box centred along right plane to balance sprung mass

• Aiming to be located in front of the driver

• Should still be protected by chassis tubes

• Dictated by exteriors for final position

Action Items for Next Meeting

1. Driver selection, max height, dimension collection, location of driver along wheelbase

2. Wheelbase track:

   1. Set track width 850-750mm

   2. Distance between front plane and front contact patch

3. Suspension:

   1. More accurate approximation of RSU

   2. Width constraint on FSU

4. Steering: Accurate approximation for linkage volume

5. battery box

   1. Lock in whether located in the front or the rear

   2. Width is constrained by distance between suspension arms minus 2x Tube Thickness

6. Exteriors:

   1. total area of array panel in reference to MS15