Clock CLACK!

[Raymond]

I have my clock out on the test bench to adjust it.  I have it hooked to a regulated 12v. power supply and it's been ticking along nicely all day... except for one thing.  At 56 second intervals the thing gives one "CLACK" and keeps ticking merrily.  It sounds like a metal relay tripping.  The clock has lost about a minute in the seven hours it's been running.

I'm mildly concerned about the clack.  Does anyone know what this might be and am I slowly killing my clock?

[DaveB]

All the mechanical clocks make a regular sound when the winding mechanism resets (guess you already knew that though). 56 seconds seems a short period if it's the resetting sound. 3-5 minutes seems normal according to Al's information: http://www.sl113.org/wiki/Electrical/Clock