Connect the tie rod to the upright, and set Ackermann.
Its position relative to the ball joint axis sets the steering arm length, which is what sets Ackermann percentage. CR26I provides one nominal and three alternate mounting points, which allows Ackermann to be swept on track rather than committed to in CAD.
No part-specific design process is documented. The Wheel Hubs subsystem design process applies: 1. Take wheel loads from the cornering, braking and combined load cases. 2. Size the spindle shaft for fatigue at the worst case, then size up to an appropriate bearing and remove as much inner material as possible. 3. Select bearings on required bore, spacing and its effect on moment reaction, static load rating against worst-case load, dynamic load rating against average load and expected life, and then the lightest and smallest option that fits. 4. Design the upright to connect the geometry points, sizing every hole and tab. 5. Analyse. Wheel load applied as a remote load from the contact patch to the bearing faces; lower ball joint and tie rod mount bolt faces react lateral and longitudinal motion; upper ball joint reacts all translation; brake caliper bolt faces take a moment reaction for braking. Global element size 0.045 in, second-order wedge elements. 6. Cross-check with the full-corner model, then state the resulting compliance. CR26I effective angular deformation of the corner in cornering is 0.32 degrees of camber change, including spindle, bearings, upright, tie rod mount and top mount.
Front tie rod mount analysed in braking and in turning deflection, both single-body and in the full-corner model. The full-corner model, which includes bolt preload, gave different stress distribution from the single-body run.
Milled on the CNC.
Al 7075-T6 or 6061-T6.
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.
Ackermann options: 16%, 23.64% nominal, 30.57%, plus an additional 23.65% larger wheel steering option used to sweep different steering effort setups and validate Ackermann. From the cost report drawings and CAD: Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. CR26I_TieRodMount (mm): 49.23, 4.92, 55.88, 5.59, 43.18, 4.32, 19.81, 1.98 Source: Cost report drawings: CR26i/Suspension/Competition/Cost Report Drawings/Suspension and Shocks/Front Upright Assembly/CR26I_TieRodMount.pdf Quantity per car, as costed: 2
Nothing in CrimsonStorage covers these yet.