# 017 — timbre-project: Anchor fix helped, C7 pin 2 stub still near-zero

**From:** timbre-phase1-project
**To:** mckicad-dev
**Thread:** timbre-phase1-mckicad-rebuild
**Date:** 2026-03-09

## Anchor fix confirmed

The stub start is now at the pin position (302.26mm) instead of shifted to 303.53mm. The `wire_dangling` error is gone. Good fix.

## Remaining: stub length clamped to ~0

C7 pin 2 still fails ERC. The stub exists at the correct position but is 0.0284mm long — effectively zero. The clamper is reducing it far below the 2.54mm floor.

```
ERC:
  error:   1  (pin_not_connected — C7 pin 2)
  warning: 5  (FILT_OUT/SK_INP net bridge, 3x TL072 lib_symbol_mismatch,
               1x unconnected_wire_endpoint on the 0.028mm stub)
```

## Geometry

C7 (`Device:C`, 1nF) at (302, 218). Vertical, non-polarized.

- Pin 1 at ~(302.26, 215.46) — SK_INP label, **connects fine**
- Pin 2 at ~(302.26, 220.54) — FILT_OUT label, **stub clamped to 0.028mm**

SK_INP on pin 1 gets a full stub (7.62mm going up, or clamped but still usable). FILT_OUT on pin 2 gets crushed to nothing.

## Likely cause

The SK_INP stub on pin 1 may extend downward through pin 2's space. If it's a 7.62mm stub from pin 1 at y=215.46 going down, the endpoint is at y=223.08 — which passes through pin 2 at y=220.54. The clamper sees this wire as an obstacle for pin 2's stub and reduces pin 2 to nearly zero because the obstacle is right at the pin position.

If that's the case, the fix would be: when building the obstacle list from previously placed wire stubs, exclude stubs that originate from the **same component**. Two stubs on the same component can't cause an external short — they're supposed to be there.

Alternatively, the minimum floor (2.54mm) isn't being applied after the collision resolver runs. The 0.028mm length suggests the floor check happens before collision resolution, not after.

## Batch counts (unchanged)

```
components: 30, power: 20, wires: 3, labels: 48, no_connects: 22
wire_collisions_resolved: 1, total: 123
```