Cuckoo 1 or 8 day movement

[Bentrider]

I bought an old cuckoo clock without its weights. According to descriptions I found elsewhere (weights to the outside, 4 wheel going train) I thought it was an 8 day movement. The time train is slightly odd, though. Chain wheel drives 2nd wheel drives 3rd wheel drives escape wheel. The 2nd wheel, however, has a smaller wheel on its shaft between mainwheel and pinion which, via an intermediate wheel, drives the centre wheel. So, before I go buying some large weights, can anyone confirm if this is an 8 day or 30 hour movement.

 

[JTD]

Is this the same movement you wrote about in your post a couple of days ago? It might have been better not to have started a new thread, to avoid confusion.

JTD

 

[Bentrider]

Yes, same movement but a different question. If it helps I'll keep any more queries in this thread.

 

[Willie X]

8-Day.

As a test, it should run dependably on any weight of about 3#.

I can probably get you a better number, if you are actually going to buy weights??

Willie X

 

[Bentrider]

There are some coming up on ebay. 1250g (about 2lb 12oz) which I thought might do the job, or would it be better to run it with a bag of rocks first to see what weight I need?

 

[R. Croswell]

There are some coming up on ebay. 1250g (about 2lb 12oz) which I thought might do the job, or would it be better to run it with a bag of rocks first to see what weight I need?

Use a "bag of rocks" with just a little more than enough weight to run the cuckoo and strike functions. Pull the weight all the way up, then turn the minute hand all the way around the dial 12 times (advance the time 12 hours) pausing to let it strike and cuckoo on the hour and the half hour. If the weight is about half-way to the floor", you have a one-day (30 hour) clock. The time and strike weights fall about the same distance. The advantage to using the strike weight is that the clock does not have to actually run, and you get the answer in just a couple minutes.

The same size bag of rocks should be a starting place for determining the size weight to make the clock run. I would suggest about 50% more weight than what will just keep it ticking, unless you can find the makers weight specification.

RC

 

[Willie X]

Bag of rocks.

Back on your leader question, long enough to extend 1/4" outside the case.

Willie X

 

[Bentrider]

Thanks all, and to R Croswell for yesterday's suggestion; someone with my penchant for physics should have realised that. Following your guidance I did a bit of googling and spreadsheet programming, fed in my numbers and came up with a pendulum length of 26cm which certainly looks about right.

 

[Willie X]

"About right" will be a lofty goal.

But it's fine to dream, just don't cut the stick!

Willie X

 

[Bentrider]

... If the weight is about half-way to the floor", ...

RC

Surely that depends on how high you mount the clock.

just don't cut the stick!

Willie X

Measure twice, cut once and all that. I'll knock up a test before I buy a proper one.

 

[R. Croswell]

Surely that depends on how high you mount the clock.

Of course it does, but typically one places a clock like this such that the weights are at the floor of nearly so when the clock runs down so they don't need a ladder to get up to it. Perhaps those with a penchant for physics would do better by measuring how many centimeters the weights drop each hour and the rate of increase as the hour count (and striking) increase each hour and use the good 'ol spreadsheet to project just how long it will run if placed x ft. above the deck.

 

[Bentrider]

Further question - How close to the back board does the gong sit. I've got about 1cm of space between the back and the whistles where a 10 cm gong would fit, or do I need an 8cm one to avoid the whistles? (pic looking from above)

 

[Willie X]

The gong would probably go in that gap but it would be best to avoid that is possible.

Weight drops are 10 1/4" per day on a Regula 8-Day. Few people are willing to hang an 8-Day cuckoo that high and settle for a nail height of no more than 80 to 82 inches. This will give you almost a 7 day run. A 9 foot ceiling can give you a 8 day run but short people won't be able to set the hands at that height ...

That's one big plus for an 8-Day over a 1-Day cuckoo. You can hang an 8-Day anywhere you have about 4 feet below the clock and that will be practical. A 1-Day cuckoo needs the 80" to 82" nail height just to function on a once a day winding schedule and I do mean schedule. You can stretch it a bit by lengthen the chains, otherwise you will have to wind it twice per day.

Willie X

 

[rjdj2000]

This appears to be your movement pictured.

 

[shutterbug]

One of our users had one a few years ago that he hung over his basement steps with a very long chain. Set the time upstairs, wind it downstairs