FSAE ELECTRIC
REAR KNUCKLE

Northeastern Electric Racing is a team of undergraduate students at Northeastern University with the goal of designing a fully-electric, open-wheel style racecar for the Formula Hybrid + Electric competition. As the Head of Dynamic Systems, I lent a hand on the rear suspension project and redesigned the rear knuckle to be lighter and more easily manufacturable. The rear knuckle is the point where the wheel, axle, brakes, and suspension come together.

FSAE Electric Rear Knuckle: Welcome

REAR KNUCKLE

OVERVIEW

- Redesign the knuckle for the rear suspension project to improve manufacturability and reduce weight

CONSTRAINTS

- Must allow proper press fit of given wheel hubs and bearings
- Must mount given brake calipers and suspension control arms

CHALLENGES

- Previous design lacked any method to hold bearings and hubs in place under the high axial loads the car will experience during cornering
- Design for in-house manufacturing with a Haas CNC Mini Mill and the limited tooling the team has
- Minimize the number of machining operations to reduce both time and cost
- Perform FEA simulations to verify the part's structural integrity with limited data on hand for the car's performance

RESULTS

- I implemented a lip and snap ring to hold hub and bearings in place during axial loading
- I reduced weight by 18%
- I altered the original geometry improve manufacturability and reduce machining time
- I made the knuckle symmetrical about its horizontal midplane so that the same part can be used on both sides of the car, and two distinct parts would not be needed
- I researched worst-case braking, acceleration, and cornering forces experienced by other FSAE cars and applied them to the given vehicle through various load calculations
- I ran static FEA simulations for cornering under both acceleration and braking scenarios, resulting in minimum factors of safety of 5.2 and 6.1, respectively
- The part was ultimately outsourced to save time in the on-campus machine shop
- The knuckle has been successfully manufactured, assembled, and installed on the car