In order for the clock to go satisfactorily, it must be set in beat. A clock is 'in beat' when the intervals between ticks are exactly equal. An 'out of beat' can be heard ticking unevenly, with alternately long and short intervals between ticks.
Carefully fit the pendulum, wind the mainsprings and gently set the clock going. After a few moments check the sound of the ticking. If it is not even, proceed as follows:
Stop the clock by holding the pendulum in the central position. Carefully move the pendulum from side to side just enough to allow the ticks to be heard, and check which direction requires the least movement from the vertical position. It is in this direction that the crutch (the part that delivers the power to maintain the swing of the pendulum) needs to be bent.
The aim is to alter the position of the crutch in relation to the escapement and it is important to establish what provisions the manufacturer has made to enable this to be done.
Many movements have friction joints which allow the crutch to be adjusted without bending. To adjust these, move the crutch in the desired direction to the limit of its free travel and then apply slight pressure. If the movement is fitted with a friction joint the crutch will move further with an even resistance. If the crutch starts to flex, let go at once. If movement of the crutch is restricted by, for instance, pins protruding from the back-plate, the escapement will have to be held with one hand while the crutch is moved.
Where no friction joint is fitted, the crutch needs to be bent. Never put any firm pressure on a crutch against the escapement as this may do serious damage. Always bend the crutch against the resistance of the other hand or between fingers of the same hand. Whichever method is used, several attempts may be necessary as there is no way of measuring the alterations you are making. Only make very small adjustments each time.
Adjusting the beat where no automatic provision is available.
Wall clocks may be given their final adjustment by moving the bottom of the case very slightly to one side. Some fine movements have screw-threaded beat adjusters, allowing for very precise adjustments.
If the movement is fitting with a friction joint, the crutch will move further with an even resistance. If the crutch starts to flex, let go at once and adjust in the conventional manner.
Final adjustment is sometimes made by slackening the two screws on the back door and rotating the whole movement imperceptibly. Re- tighten the screws to prevent the clock from rotating when being wound.