Expert: Martin Meyer - 12/18/2009

Question
Hi, I have an antique grandfathers clock which we bought in Germany. It is running well but the last gong strike does not resonate. It just goes flat? I wonder if you can explain that type of adjustment over a computer? Thanks very much.  

Answer
Hi Diane,

The strike hammer is improperly adjusted. The correct at-rest position of the hammer is 1/8" to 1/16" clearance between the hammer and the gong rod. The hammer "shaft" is usually really just a heavy soft brass or steel wire. It can be carefully bent to achieve the required clearance. You adjust it to the clearance within this range that sounds best as to loudness and does not result in a rebound strike (which sounds like a light extra strike right after the actual strike.

As to the mechanics of what is happening, each time the hammer strikes the gong rod it immediately lifts back again for the next strike, thus allowing the gong to resonate. But, at the final strike, it does not lift back again, and it is only the at-rest clearance which allows the gong to resonate. If the at-rest position leaves the hammer in contact with the gong rod, the rod cannot resonate, and is muted to a dull "klunk".

Please note that it can sometimes be difficult to achieve a position which allows the resonance, but does not make a rebound strike, especially at the higher numbers of strikes. It may take several adjustments to get the position just right. Always bend the hammer wire slowly, so as not to cause sudden metal stress that could weaken or crack the wire.  http://www.clockmasteronline.com