Shubham Nagar

SmolVLA nut stacking

Three SmolVLA policies fine-tuned on 80 physical SO-101 demonstrations and scored on the real arm. The best reached 75% full-stack success.

Best checkpoint
75% full stack, 88% pick, 92% grasp
Base policy
lerobot/smolvla_base
Dataset
160 episodes, 77,104 frames
A SmolVLA rollout on the physical arm.

Setup

Robot
SO-100/SO-101-style follower arm, driven by a leader arm for teleoperation
Cameras
Two 640×480 streams: a top view and a first-person view
State, action
6-DoF joint state in, 6-DoF joint actions out
Task
Stack one nut on another

Data

I collected 80 additional demonstrations and aggregated them with the original 80 into one LeRobot v3.0 dataset: 160 episodes, 77,104 frames at 30 fps, about 42.8 minutes of leader-follower teleoperation, with both camera streams AV1-encoded. All three policies were trained on the first 80 episodes. The dataset has no held-out split.

Best checkpoint

Training
Batch size 16, 20,000 steps, AdamW, FP32
Trained parts
Action expert and state projection; the vision encoder stays frozen
Augmentation
None
Inputs
Both camera streams and the 6-DoF joint state
Output
6-DoF joint actions in chunks of 50

Results

Share of physical rollouts reaching each stage

Share of physical rollouts reaching each stage, by checkpoint
CheckpointGrasp or betterPick or betterFull stack
Batch 16, 20k steps92%88%75%
Batch 64, 10k steps55%52%40%
Batch 64, 20k steps90%90%0%

Where it failed