Project 33

C6 — Spring margin consistency

Field	Value
Status	CONTRADICTED — Current evidence contradicts the claim or one of its requirements.
Strongest accepted evidence	MODEL ONLY
Evidence classes cited	IMPLEMENTATION, TEST PROCEDURE, ANALYTICAL
Gate reached	SOFTWARE REPRODUCTION (next: SYNTHETIC TEST)
Last review	CURRENT — snapshot recorded 2026-09-28 by tooling snapshot (no human review)

Question. Does the stated 220 N*m/rad torsion spring exceed the calculated minimum rate by at least 20%?

Current statement. At the stated design point the calculated minimum spring rate is 184.9 Nm/rad. The stated 220 Nm/rad spring gives a 19.0% margin, below the stated requirement of at least 20%. No spring has been characterized.

Requirements

ID	Requirement	Check	Bound	Observed	Result
R-C6-KMIN	The supplied spring rate is at least the calculated minimum.	machine	≥ 0.0 fraction	0.189936	SATISFIED (analytical)
R-C6-MARGIN	The supplied spring rate exceeds the calculated minimum by at least 20%.	machine	≥ 0.2 fraction	0.189936	NOT SATISFIED (analytical)
R-C6-SPRING-RATE	The supplied spring’s measured rate is 220 N*m/rad within its stated tolerance.	physical measurement	none stated	NOT MEASURED	NOT MEASURED

Predictions and measurements

ID	Quantity (condition)	Predicted	Model uncertainty	Measured	Abs. error	Rel. error	Criterion	Result
PRED-C6-SPRING-RATE	torsion spring rate of the supplied spring (spring as supplied, room temperature, within its rated angle)	220 N*m/rad [specification]	not quantified	NOT MEASURED	—	—	not pre-registered	NOT MEASURED

Known contradictions

R-C6-MARGIN
D-011

Open questions

The calculated margin is below the stated requirement (D-011).

Discrepancies

D-009 (OPEN) Model inputs were revised until paper targets were met
D-010 (OPEN) No shared design point across the mass, spring, reliability, and structural models
D-011 (OPEN) Calculated spring margin is below the stated requirement
D-012 (RESOLVED) Test named for a 20% margin did not enforce it

Assumptions

The requirement and the reported margin use the same definition: (k_supplied - k_min) / k_min.
The design point (205 m/s, 120 mm chord, 154 g fin, 50 ms deployment) is the intended one.

Limitations

The damping treatment divides by (1 - damping ratio), a heuristic.
Design-point inputs were revised to match the paper’s k_min (D-009).
No component has been measured.

Measurement needed to close the next gate

A decision on the requirement or the spring, recorded by a human.
Inert torque-angle characterization of the supplied spring (proposed pre-registration P-002).

Pre-registered experiments

P-002 (proposed)

What this claim does not establish

Any inert physical measurement: none has been accepted for this claim.
Physical performance of any hardware.
Flight readiness or safety for live propulsion.

Evidence

Artifact	Class	SHA-256 (first 12)	What it is
mechanism/spring_sizing.py	IMPLEMENTATION	`c19a9aadb9bc`	Minimum spring-rate calculation and design-point record.
docs/EVIDENCE/C6_spring_sweep.json	ANALYTICAL	`9db0f75cf68e`	k_min over egress speed and hinge-moment coefficient. The design point (205 m/s) is not on this grid.
docs/EVIDENCE/C6_design_point.json	ANALYTICAL	`85e82763995f`	The single calculation the C6 claim rests on, with every input stated.
docs/EVIDENCE/C6_spring_sweep_plot.png	ANALYTICAL	`0708c30e6618`	Rendered sweep.
tests/test_spring_sizing.py	TEST PROCEDURE	`24e6e66c244c`	Input validation and margin-arithmetic checks.

Earlier versions (failure archive)

evidence/archive/notes-v1/C6_spring_sizing.md — Historical C6 note.
evidence/archive/test_spring_sizing.v1.py.txt — Revision 1 test named for a 20% margin that accepted any k_required up to 1.2 x k_supplied.

A change to any of these files makes the last review insufficient

docs/EVIDENCE/C6_design_point.json
docs/EVIDENCE/C6_spring_sweep.json
docs/EVIDENCE/C6_spring_sweep_plot.png
mechanism/spring_sizing.py
tests/test_spring_sizing.py

All claims · Traceability · Discrepancies · Evidence Observatory

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