Introduction
The cannon pinion is the friction‑clutch component that drives the minute hand and transfers motion to the minute wheel. If the cannon pinion is incorrect—wrong fit, wrong friction tension, or wrong arbor size—the hands will slip, bind, drift, or stop. This guide explains how to choose the correct cannon pinion for your mechanical clock.
Understanding What the Cannon Pinion Does
Drives the minute hand
The cannon pinion rotates once per hour and carries the minute hand directly.
Provides friction‑clutch tension
The clutch allows hand setting without damaging the gear train.
Transfers motion to the minute wheel
The cannon pinion’s drive teeth mesh with the minute wheel to move the hour hand.
Key Features of Cannon Pinions
Arbor fit
The cannon pinion must fit the center wheel arbor precisely.
Friction clutch tension
Too loose causes slipping; too tight causes binding or hand‑setting difficulty.
Drive‑tooth profile
Must match the minute wheel for smooth motion‑works operation.
How to Identify the Correct Cannon Pinion
Match the arbor diameter
The cannon pinion must slide onto the center wheel arbor with proper friction.
Check the clutch tension
Correct tension allows smooth hand setting without slipping during operation.
Verify the drive‑tooth mesh
The cannon pinion must engage the minute wheel without binding or skipping.
Matching Cannon Pinions to the Movement
Identify the movement manufacturer
Hermle, Urgos, and Kieninger use specific arbor sizes and clutch tensions.
Match the center wheel
The cannon pinion must fit the center wheel arbor and rotate freely under proper friction.
Check minute wheel compatibility
The drive teeth must match the minute wheel’s tooth spacing and profile.
Common Cannon Pinion Materials
Brass cannon pinions
Most common and ideal for smooth friction‑clutch operation.
Steel clutch springs
Provide consistent tension and long‑term durability.
Alloy drive teeth
Used in modern clocks for improved wear resistance.
Common Mistakes When Choosing Cannon Pinions
Incorrect arbor fit
Too loose causes slipping; too tight causes binding or damage.
Wrong clutch tension
Improper tension leads to drifting hands or difficulty setting the time.
Incompatible drive‑tooth profile
Causes skipping, binding, or incorrect hour‑hand movement.
Recommended Internal Links
- How to Choose the Right Clock Minute Wheels
- How to Choose the Right Clock Center Wheels
- How to Choose the Correct Clock Third Wheels
- How to Choose the Correct Clock Fourth Wheels
FAQs
How do I know which cannon pinion my clock needs?
Match the arbor fit, clutch tension, and drive‑tooth profile to the original movement.
Why is my minute hand slipping?
The cannon pinion’s clutch may be too loose or incorrectly sized.
Can I tighten a loose cannon pinion?
Minor adjustments are possible, but excessive tightening damages the clutch.
Do cannon pinions from different brands interchange?
Only if the arbor fit, clutch tension, and drive‑tooth geometry match exactly.
Why is my hour hand moving inconsistently?
An incorrect cannon pinion can disrupt the motion‑works ratio and cause hour‑hand drift.
0 comments