Q3 SUSPENSION

There are certainly a number of methods used to support the pendulum. The most popular and time tested is the standard suspension spring. There are a number of iterations of this and many well known precision regulator clocks used the suspension spring in various forms. One of the most famous of the precision clocks ever made used a suspension spring that was ground from a single piece of stock (the Synchronome Shortt) and the best- or at least the most precise - of the precision clocks (Fedchenko) used a peculiar form of suspension spring that is not well know, but it cleverly compensated for pendulum isochronism. The knife edge suspension was also fairly widely used in precision clocks, the most well known probably is the Riefler clock although many others used it. I also designed a “rolling wire” suspension that I thought might be interesting to use but in the end, I decided against it. It seemed to me that the most robust suspension for this purpose was the knife edge and this is what I used in Q3. The knife edge doesn’t “twist” as some of the spring suspensions do and since I wanted to give impulse to the pendulum through the suspension, the knife edge seemed to me to be the most stable and practical one to use.

In designing the suspension, I mounted the pendulum in a suspension gimbal. By doing this, the pendulums will always be vertical even if the case is not exactly so. It helps solve a lot of problems in the setup.

The top of the pendulum in  it gimbal type knife edge holder. The knife edge suspension permits the pendulum to rock right to left but the pendulum is free to set itself up vertically because it has front to back freedom. This is the pendulum test bed.

A close up of the knife edge suspension in the test bed.

(RIGHT)  Both of the pendulums set up in the test bed to see if they would have enough coupling to run out of phase (they did).

A photograph from underneath of the “rolling wire “ suspension I experimented with.  I might try to use it in Q4 if it ever comes to pass.