Does a nailer's recoil slow a G1 down when it fires a whole 62-nail sheet in sequence?

What it found

The 62 nails of a 4x8 sheet fired in serpentine order, each shot's recoil transient taken from 45 MuJoCo traces of the Menagerie G1 hold model (three hold heights, three loops, 0.25–4 N s). The next nail waits until the nosepiece is back on the wall and the tip is within 0.25–4 mm; the left-over error joins the robot scatter and the shared stud-finding error in one clean-sheet probability. The wait after a shot is 0 s at 0.25 N s and up to 0.25–0.31 s at 4 N s, set by the wall coming back, not by tip position; the shortest move between nails is 0.16 s at 0.5 m/s, so a sheet is slowed by 0 s, and by 2.3–2.5 s only for a 4 N s recoil with a 1–4 m/s, 10 m/s² tip. Left-over error is at most 0.37 mm, so the clean-sheet probability is unchanged (1.00 with perfect stud reads, 0.93 with a 1 mm read): the stud finder, not recoil, keeps the budget. The recoil, loop delay, tip speed and wall are swept, not sourced; the transient is not re-simulated along the sheet and re-stancing is not modelled.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

More in Robots on the building site

• What can a Unitree G1 or H1 humanoid lift on a house-building site?Can a stock humanoid carry building materials? MuJoCo static payload envelopes of the Unitree G1 (median 4.5 kg, waist-limited; matches Unitree's 2–3 kg rating) and H1 (median 14.2 kg, elbow-limited): the G1 can carry a 2x4 but not a 2x6, the H1 can take one end of an OSB or drywall sheet with a person and set a lightweight block, but not a whole sheet, a normal-weight block or a 60 lb bag, and neither reaches an 8 ft ceiling.
• Does a framing nailer's recoil knock a stock Unitree G1 arm off the stud window?Does a framing nailer's recoil knock a stock Unitree G1 arm off the stud window? In a closed-loop MuJoCo hold, up to 4 N s of recoil moves the tip 1-4 mm (window +-3.9 mm) but 1 N s or more lifts the nosepiece off the wall for 25-140 ms; stiff loops go unstable with 10-20 ms delay (recoil, delay and wall are swept, not sourced).
• How well must a drywall-screwing robot find the framing, and do a few missed screws matter?How well must a drywall-screwing robot find the framing? A 4x8 sheet (28 wall screws, 36 ceiling) needs one read per member good to 1.0 mm for 95% clean sheets, nearly the nailing figure; allowing 3 missed screws gives 1.7 mm, averaging 4 reads 2.1 mm.
• How many hours of an 8-hour shift can a battery-powered Unitree G1 actually work, and does it change whether it pays?How many hours of an 8-hour shift can a battery-powered Unitree G1 work? One 421 Wh pack gives 4.7 h; two packs and one charger give 7.7 h; above about 300 W the charger is the limit, and pack logistics move the cost break-even only from 2.42 to 2.27 to 2.46 (draw swept, not measured).
• Can the building-site robot skills be packaged as loadable files, and does training on two plants at once cover a third?Can the building-site robot skills ship as loadable files? Five JSON skill files reload and re-score exactly; a follow skill tuned on the worse of two plants passes 68%, 65% and 70% on the rigid, flexing and MuJoCo plants, no better than tuning on the flexing plant alone (72%, 69%, 71%).
• Does a sheet-following robot skill trained on a rigid-sheet simulator survive a flexing sheet, sensing delay and actuator lag?Does a sheet-following skill tuned on a rigid-sheet simulator survive a flexing sheet with delay? It passes 81% of episodes where it was tuned and 0-11% on the held-out plant; tuning on the held-out plant gives 61-66% there.

All 27 Robots on the building site projects →

Other research topics

Proper scoring & elicitation28Effort & peer prediction9Verification games & slashing19Detection & tolerances14Markets as routers13Prediction-market design9Paying contributors8Decentralised training systems23Digital twins & sim-to-real164LLM chip design loops40Robot manufacturing loops53Ambient AI assistant46Self-replicating manufacturing34Simulation-first design64Engineered clothing45Task-specific AI accelerators40Algorithmic chip-design loops42Open-source purpose-built robots44The software-engineering loop43Adversarial human imitation41Open-source residential construction41Autonomous multi-angle capture34Sensing, imaging and 3D31Energy supply and dense energy storage39Robot societies among people31Agentic co-design of low-cost robots27Laundry-hanging robots25Machine learning on qualitative data23Robots on the building site27Civilizations & group psychology1History & human sciences1

Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.