Broken piece on pendulum

Posted: Thu Dec 08, 2011 1:51 am     Post subject: Broken piece on pendulum

Hi,

I have a grandfather / grandmother clock that was inherited. It works, however the pendulum is "twisted" a bit when it swings.

The problem can be seen in the photo here. [img]http://www.flickr.com/photos/jimandcathy/6474558069/[/img]

I circled the top where the pendulum is attached - there's a small metal piece which is broken. The best I can explain is that it's a thin metal strip that "flexes" to allow the pendulum to swing. There were 2 metal strips that flexed. 1 is broken, so pressure on the remaining one is causing the pendulum to hang crooked.

Anyway, my question is - is this a part I can get and replace on my own? If so what is it called? Is there a way to get this fixed without having a clock person come to the house or lug the clock to a workshop?

Thanks for any help. Sorry I couldn't explain it better.

-Jim

Posted: Thu Dec 08, 2011 2:16 pm     Post subject:

Jim,

The part you reference is (I believe) the suspension spring. It will look like two thicker metal plates which are bridged together by two thin metal strips. The pendulum leader (which is what the pendulum will typically hang from) is attached to the bottom plate of the suspension spring.

It is a good idea to record some movement information, as I do not know if suspension springs are universal for all movements. Klockit offers light, medium, and heavy duty suspension springs which you may reference as examples.

http://www.klockit.com/products/sku-FFFFT.html

I believe the difference really boils down to the length/weight of pendulum being used. Note that after you replace this piece, you will probably need to adjust the movement beat.

Posted: Thu Dec 08, 2011 2:36 pm     Post subject:

Hey - that's exactly the part I'm talking about!


Now I need to research how to "adjust the movement beat" - and figure out what size I need.

Thanks much - this gets me off and running - I'm glad the part is available to purchase.

-Jim

Posted: Fri Dec 09, 2011 1:48 pm     Post subject:

Beat adjustment: Note that some movements are equiped with auto-beat adjustment. This entails over-swinging the pendulum and allowing the movement to self correct. If you do not know if your movement has this feature, then you can also perform this adjustment manually.

Manual Beat Adjustment: Remove the pendulum from the pendulum leader. Above where the pendulum hangs, there should be an arm that extends out the back plate of the movement and through the pendulum leader. This is called the crutch arm. Remove the leader from this arm. Note the the crutch arm must swing an equal distance from vertical center to left as it does from vertical center to right. You should encounter slight resistance as you push the crutch arm to either side. If the swing is shorter on one side, push through the resistance on that side until you have an equal swing (from center to left and from center to right). Re-mount the leader over the crutch arm and re-hang the pendulum. Start the swing and check to see if further adjustments are required. Your movement should have an even "tick-tock". If the pendulum stops on you, then further adjustments are probably needed. Beat adjustment is a trial and error process when being performed manually.

Before doing anything, make certain the case (in particular, the movement) is level front to back and side to side. Once level, proceed with beat adjustment.