David Bond Clock Repairs

English Dial Clocks

Transport:

  • The pendulum must be removed before moving the clock.

  • It is removed by supporting then raising the pendulum weight (bob) with the left hand and easing the suspension spring out of its slot with the right hand using a suitable rod, long screwdriver or similar.

  • The suspension spring may flop forwards and re-engage with the slot - it is designed to be a loose fit in the pendulum rod.

  • If the clock is secured with steady tabs such that it can't move on the wall, the dial may have to separated from the back box in order to gain access to the steady tab fixing screws.

  • Prepare a space to lay the clock glass down on a surface, preferably covered with a towel or cloth.

  • Remove the four wooden pegs from behind the dial - they are often very tight and twisting helps. Before removing the last peg, prepare to hold the clock against the box whilst removing the last peg - after it is removed there is nothing preventing the dial from falling forward.

  • The dial may now be moved away from the wall.

  • The box may now be unscrewed from the wall.

Location:

  • On a flat wall such that the box cannot wobble.

  • Not above a heat source such as a radiator.

  • Avoid locations subject to extremes of temperature or prolonged periods of direct sunlight.

Winding:

  • Wind once per week.

  • The clock has a fusee which evens out the torque from the mainspring during the winding cycle. Because of this, the key does not get harder to turn as the clock is wound. Instead, the fusee is fitted with "stop work" which means that the key comes up against a sudden stop when fully wound. It is best to anticipate the stop, though.

  • A good technique is to count "half turns" of the key. The fusee turns once every 12 hours, so you can count 14 half turns every week's winding.

  • Note that the clock is essentially unpowered during winding, therefore it will lose time for the duration of winding.

Mounting the clock:

  • Mount the box to the wall using the central loop - make sure it's snug to the wall so the box can't wobble.

  • Mount the dial to the box using all four pegs.

  • Using a plumb line or similar set the clock absolutely vertical using the 12 and 6 indexes as a guide.

  • Whilst holding this position, mark the hole position of the steady tab or tabs on the wall.

  • Remove the dial from the box.

  • Swing the box aside to make a fixing for the steady tabs.

  • Secure the box firmly to the wall.

  • Remount the dial to the box.

  • Mount the pendulum to the back cock (bracket protruding from the back plate) and make absolutely sure the suspension pin is fully seated in the V cutout.

  • The plain side of the pendulum bob faces to the front of the clock.

Starting the clock:

  • Start the clock by gently displacing the pendulum to one side by about 20mm and releasing.

  • If it doesn't sustain, just give it the smallest nudge until it does.

Regulating the time:

  • The clock is a self-contained mechanical system and is therefore subject to external influences. Temperature, barometric pressure, vibrations, location (latitude and height) can all affect the timekeeping.

  • The nut at the bottom of the pendulum rod sets the height of the bob (weight) on the threaded rod. By changing that height, you are effectively changing the length of the whole pendulum which then changes the frequency of the pendulum - the time taken for each swing. This sets the timekeeping (rate) of the clock. The nut is called the rating nut.

  • If you want to change the rate, you need to rotate the rating nut by a given amount and in the correct direction.

  • If the clock is gaining, you need to effectively lengthen the pendulum by rotating the rating nut clockwise when viewed from above. That is, the front of the nut should be turned to the left.

  • You need to stop the clock to do this - gently bring the pendulum to rest with light finger pressure. It's sometimes helpful to put a small dot on the rating nut with a felt tip just to keep track of how much you've moved it. Grip the pendulum bob so that it doesn't rotate when you move the rating nut. Gently restart the clock by pulling the pendulum to one side by about 20mm and releasing. If the clock doesn't keep going, nudge the pendulum bob to give a greater swing.

  • Let the rate settle over a few days before further adjustment.