Jan 21, 2015 · The crutch isn’t attached directly to the pendulum. The pendulum hangs from a flat suspension spring, and swings freely. But the rod or leader of the pendulum passes loosely through a loop in the end of the crutch. So when the pendulum swings, the crutch swings. The rate of the crutch is determined by the rate of the pendulum.

Feb 20, 2019 · Ok, we have finally reached the point of this post. The clock’s pendulum stops after about 10-20 minutes. I have read up a bit on this. I have listened to the tick/tock and it sounds even to me - like a metronome. However, the pendulum does swing in a diagonal back to front motion rather than just side to side.

Oct 4, 2007 · On a "simple pendulum" setup this would cause the pendulum's period of swing to lengthen (slow down). Mercury compensating pendulums contain one or more glass or metal flasks partially-filled with mercury as counterweight. When the mercury expands, it moves up inside the flask(s), counteracting the lengthening of the iron pendulum rod.

Jan 16, 2012 · The pendulum length can be calculated from the number of teeth on each wheel above the center arbor. The pendulum length calculated will usually be from the center of oscillation to somewhere near the center of the pendulum bob. From the wheel tooth count, you can also determine the beats per hour/minute that will result in good timekeeping.

Dec 3, 2007 · But the "suspension point" of the pendulum being aligned with the verge pivot holds only for knife-edge or Cuckoo suspensions. For more conventional pendulum suspensions, the "center of flexiture" of the suspension spring should be in line with the verge pivot so that the pendulum and crutch move in the same arc.

Feb 25, 2025 · Isochronism in a clock (where the interval of the pendulum making different arcs is the same) is affected by many things including the adjustment of the escapement. If you are referring to a common recoil or anchor escapement, then increasing the "escapement depth" will increase the pendulum arc, but more importantly it will increase the recoil.

Dec 14, 2024 · I don't know how tight the thumb screw holding the suspension spring should be nor the tension screw on the piece that holds the pendulum. The clock will run for about 20 cycles of the pendulum and then you can see the piece holding the pendulum will jump/stutter and it stops. I could only upload this short clip because of file upload limitations.

Oct 17, 2016 · Calculated BPH on this one is 11,232. It is a tambour style mantle clock with a shorter pendulum than your clock. Multiply the gears together and also multiply that by 2. Then divide that answer by the result of multiplying the pinions together. Hope this helps.

Dec 21, 2008 · Saw a Japy Freres clock that has ``silk string`` suspension on Ebay. Does this mean that rather than a suspension spring the pendulum just hangs from a silk cord? Won`t this cause the pendulum to oscillate /wobble in more than just one plane? Thanks.

Jan 11, 2008 · Since pendulum length is related to the BPH (or some equivalent of measure), you can use the formula for determining BPH and solve for the correct number of teeth on the wheels. You could use the tables and formulas in "The Clockmaker's Beat Book" and back into the correct count for the number of teeth on the escape wheel.