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Apollo Snoopy Chronograph Spacing & Calibre Geometry

Omega Cal. 3861 Spec: 7.50mm Pinion Centers | ERF Clone Geometry Bench
🔭 Horological Optical Comparator
DON 90 30 12 SPEEDMASTER • 50TH ANNIVERSARY "EYES ON THE STARS" • APOLLO XIII JAW A JAW B
CHRONO TELEMETRY
00:00.00
Measured Pinion Gap
7.50 mm
Subdial / Target
3H (30-Min)
Tolerance Delta
0.00 mm
Pinion Alignment
PERFECT MATCH
⚙️ Movement & Dial Profile
Omega Calibre 3861
Spec Pinion: 7.50 mm
Genuine Co-Axial Master Chronometer. Perfect symmetrical tri-compax.
ERF Custom Clone
Spec Pinion: 7.50 mm
Modified intermediate transfer wheel train replicating genuine spacing.
Generic 7750 Mod
Spec Pinion: 8.25 mm
Unmodified Valjoux plate. Subdials sit 0.75mm too far outward into track.
VK63 Meca-Quartz
Spec Pinion: 6.90 mm
Budget modular quartz plate. Subdials squeezed 0.60mm inward toward center.
QUICK SNAP CALIPER TARGETS:
Center ➔ 3H (30-Min) Center ➔ 9H (Snoopy Sec) Center ➔ 6H (12-Hour) 3H ➔ 9H Pinion Span Subdial Diameter (9.6mm)
🔬 Horological Pinion Engineering Analysis
Scale Ratio: 10.0 px / mm
DON Bezel Check: Dot Over 90 OK
Minute Track Overlap: 0.00 mm (Clear)
Snoopy Medallion: Embossed Ag925

Why Subdial Pinion Spacing is the Definitive Tell

Standard base chronograph movements like the ETA/Valjoux 7750 have fixed center-to-subdial wheel train distances of 8.25mm. When watchmakers fit a Speedmaster dial on a standard 7750, the hands sit too far toward the perimeter, cutting directly through the minute markers. Matching the genuine Omega Calibre 3861's 7.50mm spacing requires engineering custom intermediate transfer bridge plates and custom pinions.
DIAL GEOMETRY TELEMETRY REPORT LIVE READY
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