If a weight driven clock does not have enough weight will it run fast or slow.

Eugene, Not an expert but... I would think that it would run slow to a certain point and then eventually stop. Which I don't think would be very long due to the lack of weight/power to the train compared to the weight of the pendulum bob.

Best Regards,
Tim

I think that if there is not enough weight the pendulum does not make a full ark and runs fast. The pendulum takes less time to release the escapement. The same as on a pocket watch. To weak of a spring and it runs fast.
A to strong of a spring in a pocket watch and it runs slow. But of coarse in a pocket watch to strong of a spring and you have a chance of the roller jewel to swing around a make it over bank.

This is my theory on a clock and checking what other people think.

My ansonia is running fast. It came with no weight.

Eugene,

I'm still considering this question, but if you post a picture of the Ansonia, it might help. If it's a shelf clock there is not much variance in weight.

You are right about the watch, but I don't think you can look at it exactly as a watch. I think the problem may be something else.
Do you know if it is the right pendulum weight?

I take it that rateing nut is turned to the lowest point and is still running fast.

As Dave said a picture may help.

Eugene,

Some other things to look at or check.

How much time does it gain?
Is it in perfect beat?
Does it have A maintaining power spring?
Will it run at all without the weight?

Let ds know.

Yep, that's what I'm thinking. There are a lot of variables on a clock.
Verge depth, etc.

I'm trying to fine tune a Seth Thomas Grandfather right now with a 39" long pendulum. It has two weights of different measure. And it runs with both weights, but the amplitude varies

If the Ansonia is a shelf clock, there's not much room for length variance.

Dave,

I am sure you have looked at the escape wheel already but I would look at it again closely for bent teeth. With being that the pendulum length is that long and the weight of it, it would be very easy for someone in the past to have bent some of the teeth. This would cause variance problems in the pendulum swing.

Best Regards
Tim

Tim,
I've had the clock completely apart for cleaning, and the escape wheel is fine. And the clock has a good steady beat.
I did have to adjust the verge however, and I'm not completely confident that I have the proper depthing on it yet.
All I am sure of right now, is that it runs great with the heavy weight, but I understand that the heavy weight belongs on the strike train.

Dave

If the clock is running great and strike train speed is okay I wouldn't worry too much.

I have adjusted the verge on my #2 also, by leaving the verge plate screw loose/snug and then eyeing the verge depth, then placing the movement in the clock and adjusting for best swing and running. After I got the verge set then I took the movement out and tighten down the screw. This will only effect the swing of the pendulum very little and of course I'm sure there are limitations as to the depth of the verge according to the wear of the escape wheel and the verge.

I don't know if this will compare with your Seth, but it worked for me.

Best regards,
Tim

Thanks Tim,
I am happy with the way the clock is running, but I still have some problems with the strike train.
However, I think that's a alignment issue with the train. At first after re-assembly, the clock would strike, but continue to strike after the hour count was finished.
So, I took it completely apart, and re-aligned the warning wheel, and now it won't strike unless I give it a little push.
Looks like it has to come apart again, and that's no big deal, but it's just hit and miss trying to get it right.

That is for sure! Trial and error.

Tim

Ok everyone was over thinking. It was a simple question. The simple answer is yes. The more weight the slower it runs. At least that is what I have found out so far. I added more weight to my ansonia 8 day clock. And it slowed down. This is the clock that came with the original pendant. But no weight. Here is a Link ansonia

That is the clock that I was thinking of when you originally post the question. I could understand what you are saying as an experimental theory, but I took it that you were having a problem with the clock. I also realize that there is a mathematical equation as to weight verses mass, just as a main spring matches a hairspring in a watch. As we know there is only so much weight that can be added/subtracted to a balance wheel. The same as there is only so much "fine tuning" that can be done to the rating nut of your clock.

Tim

Just enough weight is needed to get full escapement operation and a little extra bob travel. Any extra weight should not change the rate unless it was really excessive causing drag in escapement.

An interesting article. http://en.wikipedia.org/wiki/Pendulum ,
In short, my belief, it would take a somewhat large change in pendulum "amplitude" to change the "period" of swing noticeably.

Eugene,

Another thought...when you add weight and you say it runs slower, could the extra weight be causing more friction on great wheel pivots/gears/etc. causing the clock to run slower.

Just a thought!

Tim

quote:

I think that if there is not enough weight the pendulum does not make a full ark and runs fast.

Right. Acceleration of the pendulum is constant, regardless of the mass of the bob. (Think Galileo and the falling objects experiment - a bowling ball and a marble fall at the same rate) A pendulum clock with too little power at the escape wheel will (if it runs at all)run fast. Most often this is seen when the pivot (usually on the third wheel pinon end) has worn sufficiently to rob power, but not enough to stop the clock entirely, or when the spring has taken a "set". In the latter case, the clock may keep good time when fully wound, but runs fast when it is a little over half way through its duration.

Most eight day clocks, with all pivots and bushings in good order, and a new mainspring, run slow for the first day or two, and get progressively faster as they wind down, so that at the end of a week, their time-keeping is pretty close to correct.