Expert: Martin Meyer - 12/4/2007

Question
Hi, this may be a simple question to answer so i apologise in advance but i dont have a clue. I have been left an old clock (sorry there is no makers name on it) It does not have keys to wind it up. Firstly why is there a need to wind the clock up in two places? and secondly, how do i find out what size clock key to buy to wind it up- can it be done without having to take it anywhere so i can order keys online. Im not even sure if its gonna work but when the hands are moved manually its chiming in all the right places.
Thanks for any advice
Regards
Vicky

Answer
Hi Victoria,
    The hole on the left (looking at the clock) winds the strike mechanism; the hole on the right winds the time mechanism.
    Clock keys come in many sizes and vary in 1/4 mm increments. The winding arbors also wear over time, becoming smaller. It's very important to get the right size key, or the arbor might slip in the key and damage the mainspring.
    Because of the very small size increments in the keys, there is no practical way to measure an arbor accurately at home. I would suggest measuring the arbor as accurately as you can, then buying several keys of about the correct size, and trying each one to find one that fits properly. "Commercial grade" clock keys are available from any clock supply house, and are very inexpensive.