Translate front pullrod motion into damper and spring displacement at the motion ratio that gives a 150 lb/in wheel rate.
A pair of Al 7075-T6 plates pivoting on the frame, with three connection points: the pullrod, the damper, and the frame tab pivot. The ratio of the pullrod arm to the damper arm is the motion ratio.
Deflection, not stress, is the governing requirement, because bellcrank deflection shows up directly as a wheel rate change. Material chosen for deflection at minimum weight: 7075-T6 at 73 ksi yield, 10,400 ksi modulus, 0.102 lb/in^3, $73.83 per 12x12 plate, against 6061-T6 (40 ksi, 10,000 ksi, 0.0975 lb/in^3, $48.55) and grade 2 titanium (50 ksi, 15,200 ksi, 0.163 lb/in^3, $209.98).
Double shear at the pivot wherever kinematics and chassis have worked together to allow it. Geometry limits weight optimisation, because the crank has to reach three fixed points.
Single plate FEA at 0.19 in thickness: maximum von Mises 57 ksi, FoS 1.3. Front motion ratio 1.002 designed; FARO measurement found 0.997 front left and 1.007 front right. Maximum wheel rate change from deflection calculated at Ks = 150 lb/in, r = 2.2785 in/in, giving Kw = 28.679 lb/in.
Al 7075-T6, 0.19 in plate.
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
CR26I front bellcrank 82 g both plates against CR25's 87 g. Quantity per car, as costed: 2
Nothing in CrimsonStorage covers these yet.