Pendulum Suspension Spring

With the unique pendulum period adjustment system, a unique suspension spring is needed and thus needs construction. Two were made in parallel, but one ended up slightly better than the other and will be the one used. The design uses 1095 steel in the full hard condition, with brass fittings riveted to the top and bottom. The spring steel is better punched than drilled, so a small fixture was made to achieve this consistently. Following that is polishing and stress relieving of the springs by baking for an hour at 450F and then slowly returning back to ambient. Each end gets a brass rivet, and the top brass cheek gets a hole while the bottom brass cheek gets a press-fit pin from which the pendulum will hang.