**Training ACT on SO-101: From Woodpecker to 90% Success (All the Mistakes Included)**
I spent 3 weeks training Action Chunking Transformer on SO-101 for pick-and-place. Spoiler: the first attempt trained a woodpecker that just pecked the table. 🐦
**What's Different About This Post:** Most ACT tutorials show the success. I documented every failure, hardware issue, and debugging step. If you're new to SO-101/LeRobot/ACT, hopefully my mistakes save you time.
Try 1: The Woodpecker - Followed the LeRobot tutorial, collected 50 episodes - Beautiful loss curves ✅ - Robot learned to peck at table ❌ - Rookie mistakes: moving cameras, arm calibration mismatch, limited data diversity, looking at follower arm during teleop (it's cheating!)
Try 2: Engineering Upgrades - Fixed hardware setup (tape + markers everywhere) - USB udev rules for camera stability - Formal task definition with stratified sampling - Built proper eval pipeline with progress scoring - Motor breakdown mid-collection (broke the gripper with excessive force 💀) - Results: 60% in-distribution success, 10% OOD (better, but not great)
Key Learnings: - Consistent hardware setup is everything - Don't look at the follower arm during teleop - Data diversity is key for generalization - Debug infrastructure matters - Real robots break in mysterious ways (buy spare motors!)