Out of beat

Posted: Mon Jun 07, 2010 7:04 pm     Post subject: Out of beat

I have a clock with a Hermle 791-680 movement. The only way I can get an even beat is to adjust the feet way out of level. I looked for a beat adjustment but couldn't find one. Any ideas?

Thanks, Jim

Posted: Tue Jun 08, 2010 2:33 pm     Post subject:

In order to adjust the beat, you will need to remove the pendulum leader from the crutch arm and make adjustments to the crutch arm.

To set the scene: The pendulum leader is the part that the actual pendulum hangs from. The pendulum leader is hooked onto the suspension spring (which is mounted within the pendulum post at the top of the movement). The pendulum leader extends down and opens up to a “circle” (for lack of better description) that the center clock hand shaft extends through. Just above this “circular” opening, the crutch arm (which extends out of the movement front plate) inserts through a "key-hole" type slot in the pendulum leader. The “circular” portion of the pendulum leader does not allow us much room for adjustment with the leader mounted (being that the clock hand shaft extends through that “circular” opening described previously and hits the inner walls of this “circle” if you try to make adjustments).

By removing the crutch arm from the pendulum leader, you will gain room to make adjustments to the crutch arm. Crutch arm adjustment would be similar to any type of Hermle pendulum movement. You want the crutch arm to swing an equal distance from center to left as it does from center to right. You will feel slight resistance as you push it side to side, but you can push through this resistance to gain an even swing from center to left – and center to right. Once complete, replace the crutch arm, hour and minute hands, etc and allow the movement to run to see if it is in beat. If need be, repeat this process to make further adjustments to the crutch arm.

Posted: Tue Jun 08, 2010 10:56 pm     Post subject:

Chris,

That got it! Thanks.

Jim