Introduction
The motion‑works bridge supports the entire hand‑motion assembly, including the hour wheel, minute wheel, and cannon pinion. If the bridge is incorrect—wrong post spacing, wrong height, or wrong plate fit—the hands will bind, wobble, drift, or stop. This guide explains how to choose the correct motion‑works bridge for your mechanical clock.
Understanding What the Motion‑Works Bridge Does
Supports the motion‑works wheels
The bridge holds the hour wheel, minute wheel, and intermediate wheels in proper alignment.
Maintains hand‑shaft stability
Correct bridge height ensures smooth rotation of the cannon pinion and hour tube.
Controls wheel spacing
Proper post spacing prevents binding, skipping, or misalignment.
Key Features of Motion‑Works Bridges
Post spacing
The posts must align perfectly with the hour and minute wheel arbors.
Bridge height
Determines hand‑shaft clearance and dial spacing.
Plate mounting points
The bridge must match the movement’s front‑plate screw pattern.
How to Identify the Correct Motion‑Works Bridge
Match the post spacing
Even slight differences cause wheel binding or misalignment.
Check the bridge height
Incorrect height leads to hand wobble, rubbing, or poor engagement.
Verify plate compatibility
The bridge must mount securely to the movement’s front plate.
Matching Motion‑Works Bridges to the Movement
Identify the movement manufacturer
Hermle, Urgos, and Kieninger use specific bridge shapes and post spacing.
Match the hour and minute wheels
The bridge must support the wheels at the correct height and spacing.
Check cannon pinion clearance
The bridge must allow smooth rotation of the cannon pinion and hour tube.
Common Motion‑Works Bridge Materials
Brass bridges
Most common and ideal for stable, low‑friction support.
Steel posts
Provide long‑term durability and precise alignment.
Alloy mounting plates
Used in modern clocks for improved rigidity.
Common Mistakes When Choosing Motion‑Works Bridges
Incorrect post spacing
Causes binding, skipping, or misaligned hands.
Wrong bridge height
Leads to hand wobble, rubbing, or poor wheel engagement.
Incompatible mounting pattern
Prevents the bridge from attaching securely to the movement.
Recommended Internal Links
- How to Choose the Right Clock Hour Wheels
- How to Choose the Right Clock Minute Wheels
- How to Choose the Correct Clock Cannon Pinions
- How to Choose the Right Clock Center Wheels
FAQs
How do I know which motion‑works bridge my clock needs?
Match the post spacing, bridge height, and mounting pattern to the original movement.
Why are my clock hands binding?
The bridge may be misaligned or the wrong height for the motion‑works wheels.
Can I reuse an old motion‑works bridge?
Only if the posts are straight and the mounting points are undamaged.
Do motion‑works bridges from different brands interchange?
Only if the post spacing, height, and mounting pattern match exactly.
Why is my hour wheel wobbling?
An incorrect bridge can cause poor support or misalignment of the hour‑wheel arbor.
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