Carry wheel load from the rear upper A-arm into the rear bellcrank.
A push rod: the wheel moving up pushes the rod into the bellcrank. Compression is the governing case, which makes buckling the primary failure mode and is why the move to CFRP had to be validated so carefully.
Sized in the carbon component calculator using the ECCS curve fit for the composite buckling reduction factor.
1208 lb axial load over 8.1875 in, 0.981 in OD, 0.875 in ID, buckling FoS 23.056. The factor of safety is far above the 1.8 target because CR25's design was overly conservative and CR26I kept the same tube while the calculator was validated.
Cut to length with a diamond blade Dremel wheel, IPA and sanding surface prep, bonded at a 0.005 in gap with a 0.0049 in silica bond gap controller and a 0.010 in clearance fit on insert diameters, cured 24 hours at room temperature under static pressure.
Rockwest Composites 3k 2x2 twill CFRP tube, aluminium inserts, 3M DP420 adhesive, FK alloy steel rod ends. From the cost report drawings and CAD: From the cost report drawings: 3KX2 Carbon Twill (CR25_SUS_RearPushRodTube_Carbon).
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.
Tube 0.875 in x 0.981 in, 8.1875 in long, 2 in rod insert length, design FoS 2. Actuation rods total 684.35 g. 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. CR25_SUS_RearPushRodTube_Carbon (as drawn): 24.92, 2.49, 22.232.22, 207.96, 20.80 Source: Cost report drawings: CR25/Suspension/Management-Comp/Cost Report/Drawings/Sus Shocks - Rear Indirect Actuation Assembly/CR25_SUS_RearPushRodTube_Carbon.pdf Quantity per car, as costed: 2, 4
Nothing in CrimsonStorage covers these yet.