Introduction
Westclox Big Ben and Baby Ben alarm clocks use a compact, efficient movement with several dial-side springs that control alarm functions, trip levers, and setting tension. When reassembling the movement, many repairers struggle to remember the exact position of the dial-side spring. This guide explains how the spring works, where it belongs, and how to reinstall it correctly.
Understanding the Dial-Side Spring
Controls alarm lever tension
The spring provides return tension for the alarm trip lever, ensuring it resets after the alarm rings.
Maintains setting resistance
It prevents the alarm-setting knob from spinning freely and keeps the alarm hand stable.
Engages with the trip mechanism
The spring ensures the trip lever snaps into position when the alarm time is reached.
Common across Big Ben and Baby Ben
Most Westclox alarm clocks use a similar spring layout, though the exact shape varies by style number.
Easy to misplace during disassembly
Because the spring sits on the dial side, it often falls out unnoticed when the movement is opened.
Where the Spring Belongs
Mounted on the alarm trip lever post
The spring typically hooks around the post that carries the alarm trip lever.
One end anchors to the plate
A small notch or hole in the front plate holds the stationary end of the spring.
The other end pushes the lever
The active end applies tension to the trip lever, keeping it engaged with the alarm cam.
Orientation matters
If reversed, the alarm may not set, may not trip, or may fail to reset after ringing.
Check for correct preload
The spring should apply light but firm tension—too much causes drag, too little causes slipping.
How to Reinstall the Spring
Step 1: Identify the anchor point
Locate the small notch or hole in the dial-side plate where the spring’s fixed end belongs.
Step 2: Position the spring on the lever post
Slide the spring onto the post that carries the alarm trip lever.
Step 3: Hook the active end
Attach the working end of the spring to the tab or arm on the trip lever.
Step 4: Apply slight preload
Rotate the spring slightly to ensure it applies tension when the lever moves.
Step 5: Test the alarm function
Set the alarm, rotate the hands, and verify that the lever snaps cleanly into and out of position.
Common Problems and Fixes
Alarm won’t set
Spring installed backward → Reorient the spring.
Alarm hand drifts
Insufficient tension → Increase preload slightly.
Alarm won’t trip
Lever not engaging cam → Check spring position and lever alignment.
Alarm won’t reset
Spring too weak or misaligned → Re-seat the spring on the anchor point.
Movement binds when setting alarm
Spring applying too much force → Reduce preload.
Troubleshooting Flowcharts
If the alarm won’t ring
Check spring → Check lever → Check cam → Check preload
If the alarm rings continuously
Spring not resetting → Check anchor → Check lever return
If the alarm hand slips
Increase spring tension → Check setting knob → Check friction washer
If the movement binds
Spring over-tensioned → Reduce preload → Check lever clearance
If the alarm trips too early
Lever misaligned → Check spring orientation → Check cam position
Common Mistakes to Avoid
Installing the spring backward
Reverses tension direction and disables the alarm.
Over-tensioning the spring
Causes drag and premature wear.
Leaving the spring unhooked
Alarm will not reset or may not trip at all.
Forgetting the friction washer
Allows the alarm hand to drift.
Not testing before reassembly
Always test the alarm function before closing the case.
Checklist for Final Verification
• Spring anchored correctly
• Lever tension correct
• Alarm sets smoothly
• Alarm trips at correct time
• Alarm resets properly
• No binding during setting
FAQs
Are Big Ben and Baby Ben springs interchangeable?
Some are, but many vary by style number.
Why does my alarm hand drift?
Insufficient spring tension or missing friction washer.
Why won’t the alarm trip?
Spring orientation or lever alignment is incorrect.
Can I get replacement Westclox parts?
Yes—many reproduction and salvage parts are available.
Is this a beginner-friendly repair?
Yes—once the spring orientation is understood, the repair is straightforward.
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