This is an ordinary Kundo standard-sized 400 day clock made in the 1950s. Normally, I go through my standard repair process, and the clock works well.
This clock didn’t work well after repair. It ran, but the pendulum rotated only about 3 balls (where 4 balls is one full turn), and sometimes it would stop. Normally the pendulum rotates 3.5 – 3.8 balls with the mainspring wound 2 turns.
Each adjustment I made seemed to help, but after an hour, the pendulum motion would decrease.
- Closed the suspension fork tines: It helped for a while, then the motion decreased;
- Made the top block fit tighter in the saddle’
- Bushed the second and third wheel pivot holes (because the pivots were too short for the original holes;
- Tightened the fork on the suspension spring.
Finally, I tightened the lower block in the pendulum (this clock has a locking pendulum; and the lower block slides up and down in the top of the pendulum). I squeezed the top of the pendulum together to reduce the slot width, and the clock worked perfectly!
The pendulum rotation was as follows:
- Escape arc (minimum pendulum rotation at which the clock will run: 2 Balls;
- With mainspring wound 2 turns: 3.9 Balls;
- Fully wound: 4.2 Balls.
Repair job 6319. Polished 6 pivots, cleaned, installed new .0032 inch suspension spring.
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