1. Dimensions and Layout

   • 4 Wheels

   • Full Length: 350mm

   • Full Width: 200mm

   • Wheelbase: 195mm

   • Track width: 160mm

2. Wheels 

   • 76mm tires, hex and shaft couples for mounting

   • Composition: rubber tires, plastic wheel rims

3. Chassis

   • The chassis will be made of two stacked ⅛ inch baltic birch plywood

   • Manufacturing Methods - Laser Cutting at TIW

   • PLA front bumper frame with crash-resistant foam in front

   • All electronics are positioned with slots cut out from the top plywood layer on the chassis, then held down with 3D-printed clamps that screw into the chassis

4. Powertrain

   • Rear wheel drive

   • Direct drive transmission using a belt drive.

   • 4:1 gear ratio

5. Steering and Suspension

   • Suspension: None

   • Steering: A variation of “Ackermann steering” (shown in the steering design section). Ackermann is in quotations as we did not actually target ideal Ackerman angles (i.e. no slip), instead opting for a simpler design that works well enough for our use case (using two turnbuckles). The angles on both tires are almost the same while turning. We have adjusted the camber links to create a more drastic turning angle when the car is turning left. The left turning radius is 1.46ft, while the right turning radius is 2.3ft.

6. Performance

   • Curb Weight = 3.5 lbs

   • Ground clearance: 13.4mm

   • Tested Top Speed: 14.5mph

   • Acceleration: 8.10 m/s2 (0 to 14.5mph in 0.8 seconds)

   • Left Turning Radius: 1.46ft

   • Right Turning Radius: 2.30ft

   • Endurance: 864 seconds or 14.4 minutes

   • Range: 5.6km 

   • Clearance: 13.4mm

   • Caster: 22.27 degrees positive caster

   • Toe: 1-2 degree toe out on front wheels, none on rear

   • Camber: 0-degree camber on front and rear

For the final design, I focused on several goals for a few subsystems, mostly focused on a smooth ride (more solid/stable parts and connections):

• A new front bumper with higher stiffness for better crash performance

• A more compact chassis with cutouts for parts, thereby shortening our wheelbase.

• Tighter tolerances on wheels, connections, and interfaces to reduce wobble

• A better tensioning system on the rear for the belt drive

• Raising the entire chassis to increase clearance