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Train a policy

Train an ACT policy from the dataset without connecting to the robot.

01

Choose a device

Check that this guide matches your installed software. If you are unsure which version you have, the team can help you find it.

  • Use cuda for a supported NVIDIA GPU.
  • Use mps for Apple silicon.
  • Use cpu for a CPU-only run.
  • Lower batch_size if the device runs out of memory.
02

Train an ACT policy

Run training on the controller or another computer that can access the dataset. sourccey-host is not required.

Training computer · terminal
uv run lerobot-train \
  --dataset.repo_id=vulcan-studio/sourccey-demo-1 \
  --policy.type=act \
  --policy.device=cuda \
  --output_dir=outputs/train/act-sourccey-demo-1 \
  --job_name=act-sourccey-demo-1 \
  --batch_size=8 \
  --steps=20000 \
  --save_freq=5000 \
  --wandb.enable=false \
  --policy.push_to_hub=false
03

Train X-VLA on a stronger GPU

If you have a stronger NVIDIA GPU with sufficient VRAM, we recommend fine-tuning the 0.9B-parameter X-VLA base model as the higher-capacity option. Install the X-VLA dependencies first:

Training computer · terminal
uv sync --locked --extra sourccey-desktop --extra training --extra xvla
Training computer · terminal
uv run lerobot-train \
  --dataset.repo_id=vulcan-studio/sourccey-demo-1 \
  --output_dir=outputs/train/xvla-sourccey-demo-1 \
  --job_name=xvla-sourccey-demo-1 \
  --policy.path=lerobot/xvla-base \
  --policy.dtype=bfloat16 \
  --policy.action_mode=auto \
  --policy.device=cuda \
  --policy.freeze_vision_encoder=false \
  --policy.freeze_language_encoder=false \
  --policy.train_policy_transformer=true \
  --policy.train_soft_prompts=true \
  --steps=20000 \
  --policy.push_to_hub=false

X-VLA starts from the pretrained lerobot/xvla-base checkpoint and uses bfloat16 to reduce memory use. If training runs out of memory, reduce the batch size before changing the model configuration.

04

Check the output

Training should complete without dataset feature or video-decoding errors. The ACT example creates this model directory:

Training computer · terminal
outputs/train/act-sourccey-demo-1/checkpoints/last/pretrained_model

About these examples: checks against a specific software version and a full hands-on walkthrough are still in progress. The source documentation below can help you and the team confirm the right instructions for your setup.

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