2017-01-05 Managers BoT

Date

05 Jan 2017

Discuss general plan for Winter 2017
Create Gantt chart for main mechanical projects for the term
Introduce alternate powertrain design (single motor → differential → drive shafts)

Item

Who

Notes

General plan for Winter 2017

Require full CAD + simulations by end of term for:
- Space frame (FEA)
- Body (CFD)
- Suspension (FEA)
Divide term into two sprints: pre-midterm and post-midterm
- Refer to Gantt chart on Google Drive
Main components:
- Matt Suski will lead frame design
- Devon Copeland will lead suspension design
- We require someone to lead body design
Body CAD lead will be pitched on Thursday
- Candidate must be extremely committed and willing to become proficient in CAD surface modelling
- Will have limited design freedom, CAD work will be referenced to existing concept art
Goal is to contain most high-level decision making between Devon Copeland + Matt Suski + Minghao Ji

Alternate powertrain

Idea is to put a single motor inside the vehicle and connect it to a rear differential driving the rear wheels
- Would use constant-velocity universal joints to connect drive shafts to the wheels
- Several potential options for physical orientation of motor and differential
- This is how it's done in practically all production vehicles (such as the Tesla Model S)
Benefits:
- Greatly simplify suspension upright design, especially brake mounts
- Eliminates the concern of matching torque of two separate motors
- Greatly reduces unsprung mass, improving handling
- Eliminates a motor controller from car, recovering some space/wiring
- Reduced motor failure rate, more spare motors
Cons:
- Reduced torque/power, greater losses due to friction in differential and drive shafts
- Greater mechanical complexity inside car
- Affects placement of battery boxes
- May require a new motor
This will be discussed prior to the Thursday meeting between Devon Copeland + Matt Suski + Minghao Ji