Clockmaking · Interactive explainer

Pendulum clock regulation explorer

Turn measured gain or loss into daily rate error, required pendulum length change, approximate bob movement, rating-nut turns, and temperature drift by rod material.

Observed clock behaviour

Results update instantly as you type. Use the button only if you want a shareable URL.

Positive means the clock gained time. Negative means it lost time.

Metric pitch uses mm per turn. TPI uses threads per inch.

What this page answers

Pendulum-clock advice often stops at “raise the bob if it is slow, lower it if it is fast” and then leaves out the only practical question: by how much. This page converts an observed rate error into a concrete adjustment.

  • Turns a multi-day timing check into seconds per day.
  • Estimates the effective-length change required to correct the rate.
  • Translates that into approximate bob movement and rating-nut turns.
  • Shows how temperature drift changes with steel, brass, wood, or Invar rods.

Read the launch note for this clockmaking tool.

At-a-glance answer

Adjustment detail

Temperature drift