Crimson Racing Wiki

Front Tie Rod Tube

Subteam: ChassisSubsystem: SteeringAssembly: Front Tie Rod AssemblyCars: CR25, CR26I

Purpose

The tube section of the front tie rod assembly.

Function

A tube in tension and compression. Buckling governs in compression, so sizing runs against critical buckling load before it runs against yield.

Design Process

No part-specific design process is documented. The Steering subsystem design process applies: 1. Kinematics sets steering geometry, Ackermann targets and rack travel. 2. Size the column and shafts for torsional stiffness and for the bearing housing that supports them. 3. Calculate static steering force from the tire and geometry, and check it against anthropometric limits. 4. Design the wheel shell around the button and switch layout and the dash sightline; prototype grips and take driver feedback. 5. Validate steering effort and Ackermann on track, using the alternate tie rod mounts to sweep setups.

Manufacturing Process

Cut to length, then welded or bonded to its end inserts.

Full Material List

Rockwest Composites 3k 2x2 twill CFRP, 0.750 in ID x 0.856 in OD. From the cost report drawings and CAD: From the cost report drawings: 3K2x2 Twill Weave Carbon Fiber (CR25_SUS_FrontTieRodTube_Carbon); 3K 2x2 Twill Weave (CR26I_FrontTieRodTube).

Reoccuring issues

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.

Properties

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. CR25_SUS_FrontTieRodTube_Carbon (as drawn): 19.05, 1.91, 347.22, 34.72, 21.74, 2.17 CR26I_FrontTieRodTube (mm): 21.7, 19.1, 347.2 Source: Cost report drawings: CR25/Suspension/Management-Comp/Cost Report/Drawings/Steering - Front Tie Rod Assembly/CR25_SUS_FrontTieRodTube_Carbon.pdf; CR26i/Suspension/Competition/Cost Report Drawings/Steering System/Front Tie Rod Assembly/CR26I_FrontTieRodTube.pdf Quantity per car, as costed: 2

Still to document

Nothing in CrimsonStorage covers these yet.