Introduction
The suspension spring is a critical regulation component that supports the pendulum and allows it to swing freely. Choosing the wrong suspension spring leads to fast or slow timekeeping, poor pendulum amplitude, or a clock that stops entirely. This guide explains how to choose the correct suspension spring for your mechanical clock.
Understanding What the Suspension Spring Does
Supports the pendulum
The suspension spring holds the pendulum rod while allowing controlled oscillation.
Controls timekeeping rate
Spring thickness and flexibility directly affect the pendulum’s period.
Absorbs minor shocks
A proper suspension spring protects the pendulum from sudden movement.
How to Identify the Correct Suspension Spring
Match the spring thickness
Thicker springs make the clock run faster; thinner springs make it run slower.
Match the spring length
Length affects pendulum geometry and must match the movement’s design.
Check the top and bottom block style
Different movements use pinned, slotted, or screw‑mounted blocks.
Matching Suspension Springs to the Movement
Identify the movement manufacturer
Hermle, Urgos, and Kieninger use specific suspension lengths and block styles.
Match the pendulum rod style
Some rods require narrow springs; others require wide or reinforced designs.
Check crutch compatibility
The crutch foot must align with the suspension spring’s lower block.
Common Suspension Spring Materials
Tempered spring steel
Most common and ideal for consistent regulation.
Alloy springs
Used in some modern clocks for improved flexibility and durability.
Brass‑mounted springs
Common in antique clocks with pinned block designs.
Common Mistakes When Choosing Suspension Springs
Using the wrong thickness
Even small differences cause major timing errors.
Incorrect block style
Prevents proper mounting and can cause the pendulum to bind.
Wrong length
Alters pendulum geometry and causes poor amplitude or stopping.
Recommended Internal Links
- How to Choose the Correct Clock Crutch Assemblies
- How to Choose the Right Clock Verge Assemblies
- How to Choose the Right Pendulum Rods
- How to Test a Clock Train During Reassembly
FAQs
How do I know which suspension spring my clock needs?
Match the thickness, length, and block style to the original movement specifications.
Why is my clock running fast or slow?
Often caused by incorrect suspension spring thickness or length.
Can I trim a suspension spring?
Length can be adjusted slightly, but thickness must match exactly.
Do suspension springs from different brands interchange?
Only if the thickness, length, and block style match perfectly.
Why does my pendulum have poor swing?
The suspension spring may be too stiff, too thin, or incorrectly mounted.
0 comments