---
license: mit
task_categories:
- robotics
tags:
- LeRobot
- robotwin
- sim
- franka
configs:
- config_name: default
  data_files: data/*/*.parquet
---

# stackblocks-stage3-v1 — RoboTwin stack-blocks-two task finetune data

Stage-3 of a 3-stage curriculum (DROID CoT pretrain → playground @grip conditioning →
**task finetune**). 45 human-teleop episodes of the `stack_blocks_two` task (Franka,
RoboTwin sim) — the source dataset of the T-series / EE-noCoT ablation campaigns.
LeRobot **v2.1 video/h264**, schema-identical to `Numbnut/playground-stage2-v1` and
`Numbnut/droid-keeps-v6`:

- `observation.images.ext` = bird_eye (**the `<loc>`/@grip grounding view**), 320×240
- `observation.images.wrist` = right_camera
- `observation.state` (8,) = joint qpos (7) + gripper open (1=open)
- `action` (7,) = EE delta-euler + gripper (`compute_ee_delta_actions`)
- task = the REAL per-episode instruction (goal-directed, e.g. "Relocate red block to
  the middle and place green block on it.")

Conversion specifics (see `droid_provenance.json`):

- **30→15fps stride 2** — tempo parity with stage-2. NOTE: the historical T-series/EE
  repos were native-rate; per-stored-frame deltas here are ~2× those — do not compare
  models trained here against the historical EE-noCoT/T-series numbers directly.
- **Static-prefix trim 0.05 rad** (T-series-proven; mean ~14 frames): `trim` maps each
  episode's source-frame offset. Any future CoT span table must map
  `kf_lerobot = (kf_source - trim) // stride`, dropping kf inside the trimmed prefix.
- **held_out = []**: stage-3 eval is closed-loop sim (`run_benchmark.py --episodes 50
  --seed-offset 100 --step-limit 800`), all 45 episodes train. Keep
  `cot_exclude_held_out=False` for this repo.

No CoT span table yet: the existing `annotation_v5.json` files in the source tree are
an older API format (per-kf A only); v5-span regeneration (template annotator) is a
pending, separately-reviewed step.

Built by `policy/pi05-pure/scripts/convert_franka50_to_lerobot.py` in the RoboTwin fork.