Clock Knowledge?

[wristpin]

Any suggestion as to why a long case (grandfather) clock that should run for 6/7 days per wind, stops after completing three 24 hour cycles perfectly. Local "expert", says "weights catching on something" but they are not. Wondering id the cords that carry the weights are binding in the grooves on the drums - but not visibly.
Any thoughts?

 

[pedrobedro]

Probably needs a clean and a bit of lubrication.

 

[Cobbler]

Are the cords crossed over, sort of coil bound, so one coil is over the other so it's trapped?

 

[wristpin]

Thanks for suggestions, but.....
Cords not trapped and been cleaned/lubricated. Seems strange that it keeps perfect time for three twenty four hour cycles then stops as the weights exert constant pull.
Would make more sense if it stopped part way through the first 24 hours.
Going to take the mechanism out of the case and run it on a test stand where every thing is visible. Sod’s law says that it will run perfectly!

 

[Cobbler]

Sometimes they will stop at a specific time if they need cleaning & oiling. When they come up to strike & you get the warning at about 5 to the hour, there's not enough power left to lift the mechanism due to the resistance of the movement. This would not explain why it will go for 3 days perfectly though, it would stop randomly.

Rough cord with a thread caught under the next coil? I would say let it stop & have a really good look at the weights & cords. Is the hand catching on anything when it stops, I know this wouldn't explain the 3 days, but something to check.

 

[Barking Mat]

Is it dead dead level? Had the same problem, mini spirit level time.

 

[wristpin]

Is it dead dead level? Had the same problem, mini spirit level time.

Yes, level in all directions with a bullseye.

 

[rtbcomp]

I bet there's a couple of gears that line up in a certain way every 3 days. If the engaging teeth on both gears are burred then it could cause the clock to stop, but when a burred gear engages with a normal gear it gets past OK.

 

[wristpin]

I bet there's a couple of gears that line up in a certain way every 3 days. If the engaging teeth on both gears are burred then it could cause the clock to stop, but when a burred gear engages with a normal gear it gets past OK.

I like the logic of that suggestion - will observe closely next time it stops.

 

[rtbcomp]

Maybe mark the relative positions of the gears with a marker pen and try a few times?

 

[the artfull-codger]

It doesn't need to be perfectly level or plumb, what it needs to be is "in beat" ie listen to it to ensure that it goes tic toctictoc evenly when the pendulum reaches the end of its travel & not tic toctic sometimes if the case is a bit rickety by the time the weights travel so far down the case will rock ever so slightly causing it to lose momentum, the escapement might be worn, 2 schools of thought there, obviously don't oil the gears but a very slight amount of oil on the escapement helps but some never oil the escapement.

 

[rtbcomp]

... if the case is a bit rickety by the time the weights travel so far down the case will rock ever so slightly causing it to lose momentum...

Try winding it so the weights stop in a different place then see if it runs for 3 days or stops where the weights would have been after 3 days had you wound it fully.

 

[roofman]

Get some metric rope or springs that have had a complete education...I have been looking for a decent clock shop for my 7 day mantel clock too with no success, where are all the old skills going these days?

 

[Robotstar5]

Get some metric rope or springs that have had a complete education...I have been looking for a decent clock shop for my 7 day mantel clock too with no success, where are all the old skills going these days?

We still have a few in the Jewelry Quarter in Birmingham.

 

[winchman]

Get some metric rope or springs that have had a complete education...I have been looking for a decent clock shop for my 7 day mantel clock too with no success, where are all the old skills going these days?

This Man in St.Helens is excellent
http://www.fixingtime.co.uk
I bought a 50s watch from the car boot as winchboy likes them but the winder was missing, he was the only person who would take the repair on, two years later it still keeps perfect time.
Nice bloke too but often very busy as he does a lot via post