Kundo Clock Suspension Spring New Parts: A Complete Guide

If you own a Kundo 400-day clock, you know that the suspension spring is a critical component that keeps the timekeeping accurate. Over time, these springs can stretch, corrode, or break, leading to erratic timekeeping or a stopped clock. Finding the right Kundo clock suspension spring new parts can restore your clock to its original performance. This guide walks you through everything you need to know—from identifying the correct spring to installing it properly.

What Is a Kundo Clock Suspension Spring?

The suspension spring is a thin, flat steel ribbon that hangs from the top block inside the clock. It supports the pendulum and allows it to twist back and forth as the clock runs. In torsion pendulum clocks (also called anniversary or 400-day clocks), the spring’s elasticity determines the pendulum’s rotation speed and thus the timekeeping accuracy. When the spring loses its temper or breaks, the pendulum may wobble, the clock may run fast or slow, or it may stop altogether.

Types of Suspension Springs for Kundo Clocks

Kundo clocks were made in many models over decades, and the suspension springs vary by length, thickness, and end attachments. The most common types include:

• Thin spring (standard): Found in most Kundo models, typically about 0.0020 to 0.0030 inches thick. Lengths range from 3 to 4.5 inches.
• Thick spring (heavy pendulum): Used for larger pendulums or clocks with more torque, usually 0.0035 to 0.0045 inches thick.
• End blocks differ: Some springs come with a single block at the top, others have two blocks (top and bottom). The bottom block attaches to the pendulum leader.
• Hole patterns: The top block may have one hole for a pin or a splayed end that hooks onto the suspension bracket.

To ensure a proper fit, you must match the spring’s dimensions exactly to your clock’s original specifications. Using the wrong thickness will cause timing errors; incorrect length may prevent the pendulum from leveling.

How to Identify the Correct Suspension Spring for Your Kundo Clock

Choosing the right Kundo clock suspension spring new parts starts with identifying your clock model and pendulum weight. Here’s a step-by-step approach:

1. Check the clock’s back plate. Look for a model number or patent dates. Common Kundo models include the 94, 95, 96, 97, and 1000 series. The model often dictates the spring size.
2. Measure the existing spring. If the old spring is intact, measure its length from top block to bottom block (or end to end). Also note the thickness using a micrometer. If unavailable, measure the pendulum’s rotation: a heavy pendulum usually needs a thicker spring.
3. Inspect the pendulum. Some Kundo pendulums have a removable disc; the weight can be increased by adding discs. Heavier pendulums require thicker springs to support the torque.
4. Consult a parts chart. Many clock supply websites have charts matching Kundo models to suspension spring sizes. Look for a chart that lists model numbers and recommended spring dimensions.
5. Consider the suspension bracket style. Kundo used two main bracket designs: a hook-and-pin style and a collet style. Your new spring’s top block must match the bracket. If you’re unsure, a universal spring with a removable top block can be adapted.

If you cannot find the exact model, a common safe choice is a 0.0028-inch thick spring about 4.5 inches long with a top block that has a single hole for a pin. Many Kundo clocks use this size.

Where to Buy Kundo Clock Suspension Spring New Parts

You can find Kundo clock suspension springs at specialty clock parts suppliers and clock repair shops. Sources include:

• Clock parts distributors that stock Horolovar or other 400-day clock parts. They offer springs by size and include instructions.
• Watch and clock supply houses such as Timesavers or Merritt’s (note: these are general material houses; verify stock).
• Specialized 400-day clock parts dealers that focus on Kundo and Schatz models. These vendors often provide detailed fitting guides.
• Clock repair shops that sell parts over the phone or online. Some will also help identify the correct spring if you send them your old spring’s measurements.

Avoid generic springs from hardware stores; they are usually too thick or weak. Stick to purpose-made Kundo clock suspension spring new parts from established clock material companies. When ordering, confirm the spring’s dimensions and block style with the seller—most are happy to verify fitment.

Installation Tips for Kundo Suspension Springs

Replacing a suspension spring is delicate but doable with patience. Follow these tips:

1. Prepare your workspace. Wear cotton gloves to avoid oil from your skin; oil can weaken the spring’s elasticity. Use tweezers to handle the spring.
2. Remove the old spring. Carefully unhook the pendulum, then remove the top pin or collet. Note the orientation of the old spring—you’ll need to install the new one the same way.
3. Attach the new spring’s top block. Insert the spring into the slot and secure it with the same pin or collet. Ensure the spring is centered and not twisted.
4. Install the bottom block. Attach the pendulum leader to the bottom block. Some leaders have a hook; others use a pin. Make sure the pendulum hangs straight.
5. Level the clock. Adjust the leveling feet until the pendulum rotates evenly without wobbling. The pendulum should rotate at least one full turn in either direction.
6. Regulate the time. The regulating nut may need minor adjustment. Rotating it clockwise typically speeds up the clock. Allow 24 hours to check accuracy.

If the pendulum wobbles excessively, the spring may be too thin; if it rotates too slowly, the spring may be too thick. Recheck dimensions.

Final Recommendation

For most Kundo 400-day clocks, a standard 0.0028-inch thick suspension spring with 4.5-inch length and a single-block top works well. However, always verify using your clock’s model number and pendulum weight. Buy from a reputable clock parts supplier that offers returns if the fit is incorrect. A quality suspension spring will last for years if handled gently and kept free from dirt and moisture. If in doubt, bring your clock to a professional repairer who can measure and order the exact part. Investing in the correct Kundo clock suspension spring new parts will keep your clock running smoothly for many anniversaries to come.