# Autonomous session summary (2026-07-02/03)

Ran 13 iterations, then stopped per the self-limit: **gantry + mobile-base are substantially fleshed out**.
Rather than churn low-value iterations toward the 24-row cap, wound the loop down here. Frozen arm print
files were never touched.

## What got built

### Gantry (NEXT horizon) — now comprehensively designed & buildable
- `gantry_arm_motorized.urdf` — full drivetrain: 3× NEMA17, T8 leadscrew + nut-block (self-locking vertical),
  MGN12 rails (3 axes), GT2 pulleys + belt loops (X/Z), real printed carriage plates + wrist bracket.
- Printed parts (all watertight): `nema17_mount.stl`, `carriage_plate.stl`, `nut_block.stl`,
  `gantry_wrist_bracket.stl`. Motor/drive meshes: `nema17.stl`, `leadscrew_t8.stl`, `mgn12_rail.stl`,
  `gt2_pulley.stl`, `belt_x/z.stl`.
- Docs: `docs/gantry/README.md`, `IMPLEMENTATION_GUIDE.md` (how to build a linear axis + the vertical-axis
  back-drive concern), `BILL_OF_MATERIALS.md` (~$250), `WIRING.md` (steppers/endstops/homing/firmware).

### Mobile home robot (LATER horizon) — two variants prototyped
- `mobile_base.urdf` v2 — differential drive (2 driven wheels + 2 casters) + vertical lift + 4-DOF arm.
- `mobile_gantry.urdf` — wheeled base + compact 3-axis gantry (the fetch-like idea).
- Docs: `docs/home_robot/README.md` + `BILL_OF_MATERIALS.md` (~$500–700). Lift = self-locking T8 leadscrew.

### Polish
- Gravity-comp spring buy-spec + zero-free-length caveat + tuning (`docs/gravity_comp/README.md`).

## State of the checklist
- NOW (print the arm): unchanged & frozen — ready for Cameron to print.
- NEXT (gantry): design complete; ready to source parts (BOM) and build (guide + wiring).
- LATER (mobile): concept + two URDFs + BOM; real multi-week build when the time comes.

## If resumed
Genuinely-useful remaining work (not churn): a gantry workspace/reach kinematics note; assembly "hero"
renders; a mobile controller/nav software plan; wiring the mobile lift leadscrew into mobile_base.urdf.

Iterations detail: iter_1.md … iter_13 (INDEX.md rows 1–13).