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[OpenArm Troubleshooting] Jog Works but Pick Height Is Off After Shift Handoff (Intermediate)

Jog looks normal but first pick misses after handoff? Catch stale fixture references early and prevent shift-to-shift yield loss.

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A tricky OpenArm handoff problem appears when the robot jogs normally, but the first real pick after a shift change misses height by enough to scrape, hover, or fail contact. Motion looks healthy, yet the operational reference is no longer trusted.

How are you diagnosing OpenArm cases where jog commands work but fixture pick height is off after a shift change?

Please share how you separate robot health from fixture-reference drift, which handoff checks catch the issue before production or demos resume, and what changeover routine keeps the next operator from inheriting a bad reference.

If you reply, include one exact pick-height symptom and one exact shift-change or fixture check that exposed it.

Related troubleshooting path: End-effector Z check fails after table move · Base mount shift and calibration mismatch

Module: OpenArm · Audience: builders-integrators · Type: question

Tags: openarm, shift-change, pick-height, fixture

Comment 1

Intermediate context: We saw this right after night-shift handoff: jog looked perfect, but first tray pick was consistently 2.1 mm high and vacuum never sealed. The miss was uniform across three pockets, so we suspected reference carryover instead of random motion error.

Comment 2

Intermediate context: Fastest check for us was a shift-start gauge block touch at two fixture corners plus center. Z delta was +2.0 to +2.2 mm on all three points, which ruled out single-pocket drift and immediately pointed to a stale handoff reference.

Comment 3

Intermediate context: Our release rule now is simple: 15 consecutive first-part picks after handoff, no scrape, and pocket-height residual under 0.3 mm. We also save the shift baseline with operator name and timestamp so the next shift can verify in under 60 seconds.

Comment 4

Intermediate context follow-up: Follow-up question: what handoff artifact do you store now (fixture snapshot, baseline vector, or checklist), and which one reduced first-part misses the most?

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Quick FAQ

Why can jog be normal while first pick fails?

Jog validates motion path, not handoff reference integrity; stale fixture baselines can pass jog and fail picks.

python tools/handoff_baseline_check.py --fixture tray_A
python tools/first_pick_probe.py --cycles 15 --log baseline_shift.json
What handoff artifact should we keep?

Store one baseline vector snapshot with operator timestamp for next-shift verification.

Can I copy these commands as-is?

Use them as a checklist template first. Confirm interface names, fixture IDs, and safety conditions in your own cell before execution.