How to use Codex to calibrate a robot brush tip
Codex inferred a robot brush-tip offset from three uncalibrated camera views, checked new wrist angles, and operated within the maker’s motion safeguards.
reddit.com
Suggested prompt
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Estimate this robot brush tip’s 3D offset using the three camera views and small approved motion probes. Learn how each camera responds to movement, then validate the estimate at new wrist angles. Use only the existing checked motion executor, preserve the hardware emergency stop, and report measurement limits before a drawing run.
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See placements →Evidence at a glance
Sourced account- Source author
- u/dhvanil
- Original account
- Read the source ↗
- Published
- Source link checked
- Reported result
- Codex inferred a brush-tip offset from three uncalibrated camera views and checked it at new angles; the maker reports less than 0.2 mm camera-measured movement.
- Human involvement
- The owner built the physical rig, supplied direction and follow-up, judged the result, and retained a hardware emergency stop outside agent control.
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How the agent did it
- The maker supplied three camera views after earlier brush-tip calibration approaches had proved difficult.
- Codex moved the arm in small probes and inferred the tool offset from camera motion.
- It checked the offset at new angles within the owner’s constrained motion and emergency-stop setup.
The maker behind PB27 had struggled to locate a robot brush tip accurately using calibration boards, switches, and a touchscreen. A Codex session using Astra tried a simpler observation loop with three cameras whose intrinsic and external calibration parameters were not provided.
The agent nudged the robot arm, observed how each camera saw the movement, and inferred the brush tip’s three-dimensional offset. It then checked that estimate at additional wrist angles. The original Reddit account says the work followed one prompt and a short follow-up; the maker’s technical page reports camera-measured tip movement below two tenths of a millimetre during the new-angle check.
The wider physical setup matters. The owner built the rig and judged the results. Motion went through checked executors, and an independent hardware emergency stop remained outside the agent’s software. The technical context records calibration changes so that moved paper or adjusted tools do not silently reuse stale measurements.
The result was a verified tool-offset estimate for this drawing robot. It is a particular camera-measured calibration, rather than a certified absolute-accuracy specification or evidence that unrestricted robot motion is safe.
Prompt
Suggested prompt (written by Agents In Use, not the author's)
Source: Reddit · u/dhvanil
Frequently asked questions
Did the cameras come with calibration parameters?
The account explicitly says no intrinsics or extrinsics were supplied.
How was the estimate checked?
The agent verified the tip at additional robot wrist angles.
Is the reported value certified absolute accuracy?
No. It is the maker’s camera-measured movement in that check.
More details
About this account
The maker supplied three camera views after earlier brush-tip calibration approaches had proved difficult. Codex moved the arm in small probes and inferred the tool offset from camera motion.
Opened original Reddit thread plus author’s dhvanil.com/pb27 and pb27.txt technical context. Date is explicit in indexed original-thread data and corroborated by author timeline. Camera movement is not certified absolute metrology. Original prompt was not shared. Suggested prompt written by Agents In Use; no original task prompt was published in the verified account.
Credit: u/dhvanil — Reddit
Source published
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Tools and topics
Codex · UFactory xArm 7 · three cameras · robot SDK
robot calibration · camera feedback · physical verification
Editorial completeness: 100/100. Measures documented fields, not agent performance or verified outcomes.