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Activity 001: Scanner Calibration and First Scan

Activity ID: U11M2-ACT-001 Duration: 45 minutes Objective: Learners will perform a complete scanner calibration procedure, verify calibration accuracy using a reference object, and execute their first structured light scan of a simple test object.

Overview

This hands-on lab walks students through the full calibration-to-first-scan workflow. Students will calibrate the scanner, verify accuracy by measuring a known reference artifact, then scan a simple geometric test object and evaluate the raw scan quality. This establishes the foundational skills used in all subsequent scanning activities.

Materials & Equipment Needed

  • Desktop structured light 3D scanner (one per 2-3 students)
  • Manufacturer-supplied calibration target (matching working volume)
  • Reference artifact: gauge block or calibration sphere with known dimensions
  • Test object: simple geometric shape (machined metal block, chess piece, or similar)
  • Computer with scanner software installed
  • Calipers or micrometer for manual measurement comparison
  • Scanning spray (if test object is reflective)
  • Microfiber cloth for cleaning calibration target
  • Student worksheet (Calibration & First Scan Log)

Instructions & Procedure

Phase 1: Scanner Setup and Calibration (15 minutes)

  1. Unpack and position the scanner on a stable, vibration-free surface. Connect USB and power cables.
  2. Clean the calibration target with the microfiber cloth — fingerprints and dust degrade calibration quality.
  3. Launch the scanner software and navigate to the calibration module.
  4. Select the correct calibration target in the software (match the serial number or size marking on your physical target).
  5. Follow the software calibration wizard:
  6. Capture the target at 8-12 positions: vary angle (tilt left 20°, right 20°, forward 20°, back 20°) and distance (near, mid, far within working range)
  7. Ensure the target fills at least 50% of the camera view in each capture
  8. Watch for the software's feedback — green indicators mean good capture; red means retry
  9. Review the calibration report:
  10. Record the reprojection error (target: < 0.1 pixels)
  11. Record the residual accuracy value
  12. If either value exceeds the scanner's specification, recalibrate
  13. Record all calibration values on your worksheet

Phase 2: Calibration Verification (10 minutes)

  1. Place the reference artifact (gauge block or sphere) on the scanning platform at the optimal working distance
  2. Scan the reference artifact using default settings
  3. Measure the artifact in the scanner software:
  4. For a gauge block: measure the distance between two parallel faces
  5. For a sphere: fit a sphere to the point cloud and record the computed diameter
  6. Compare scanner measurement to known value:
  7. Calculate the deviation: Scanner measurement - Known value = Error
  8. Record on worksheet: Does the error fall within the scanner's stated accuracy?
  9. Measure the same artifact with calipers/micrometer for comparison
  10. If the scanner measurement deviates beyond specification, recalibrate and re-verify

Phase 3: First Object Scan (15 minutes)

  1. Prepare the test object: Inspect for reflective surfaces. Apply scanning spray if needed (thin, even coat).
  2. Place the object on the turntable (or scanning platform), centered and stable
  3. Configure scanner settings:
  4. Set exposure: Adjust until the projected pattern is clearly visible on the object surface without saturation
  5. Set resolution: Use medium resolution for this first scan
  6. Verify working distance is within range
  7. Execute a turntable scan:
  8. Set turntable to 24° angular steps (15 scans per revolution)
  9. Start the automated scan sequence
  10. Monitor the real-time preview for quality — watch for missing patches, excessive noise, or tracking loss
  11. Review the raw scan result:
  12. Rotate the point cloud to check for completeness
  13. Identify any occlusion holes or missing surfaces
  14. Note any areas with excessive noise or artifacts
  15. Record observations on your worksheet: point count, estimated coverage percentage, any quality issues

Phase 4: Review and Debrief (5 minutes)

  1. Compare your results with the group at your table
  2. Discuss: What worked well? What was challenging?
  3. Instructor reviews common issues observed during the session

Discussion Points

  1. How did the calibration reprojection error compare across different stations? What might cause variation?
  2. Did the scanner measurement of the reference artifact match the caliper measurement? If not, why?
  3. What areas of the test object had the best vs. worst scan quality? What caused the difference?
  4. How would you change your approach if the object were twice as large? Half as large?

Expected Outcomes

  • Completed calibration with reprojection error within manufacturer specification
  • Verified scanner accuracy against a known reference artifact (deviation documented)
  • First scan of a test object with at least 80% surface coverage
  • Completed Calibration & First Scan Log worksheet with all measurements and observations

Assessment Rubric

Criterion 4 (Excellent) 3 (Good) 2 (Fair) 1 (Needs Improvement)
Calibration Execution Completed independently with optimal target orientations; reprojection error well within spec Completed with minor guidance; acceptable reprojection error Required significant assistance; borderline calibration quality Unable to complete calibration; poor target positioning
Verification Measurement Accurate measurement with deviation analysis; compared to manual measurement Measurement completed; deviation calculated Measurement completed but deviation not analyzed Measurement not completed or grossly inaccurate
Scan Quality High coverage (>90%), minimal noise, good exposure settings Good coverage (>80%), acceptable noise levels Moderate coverage (60-80%), some quality issues Poor coverage (<60%) or severe quality problems
Documentation Thorough worksheet with all values, observations, and analysis Complete worksheet with most values recorded Partial worksheet with key values missing Incomplete or missing worksheet

Safety Considerations

  • Do not stare directly into the scanner projector during operation
  • Apply scanning spray only in well-ventilated areas; wear nitrile gloves and safety glasses
  • Handle calibration targets carefully — they are precision instruments; do not drop or scratch
  • Keep liquids away from electronic equipment
  • Report any equipment damage or malfunction immediately

Last Updated: 2026-03-19