Why Slow?

[bangster]

This question concerns the ordinary balance-wheel movement found in our old friend, the Westclox Big Ben. I seek wisdom.

It's my belief that a power loss somewhere in the train will lead to reduced oscillation of the balance, making the clock run faster. Rule: If it's running fast, look for the power loss.

That being the case, what do I look for if it's running SLOW? Parity of reasoning would suggest "look for the power gain", but I ain't gonna buy that for a minute.

So, where do I look instead? And is my belief about power loss mistaken? :confused:

He'p me.

bangster

[Veritas]

I would think slow running, would signify dirty and needs a clean and lube hob.
Like you said, wear through out movement would make balance wheel oscillate slower.Meaning it likely needs bushing work.

[Mike Phelan]

I don't think a pin-pallet escapement clock will make a clock slow because of an escapement or train problem.

If the pins are badly worn, they sometimes run fast.

Back to your clock:

Has it gone like that suddenly or gradually?
If you have only just got it, has the hairspring been got at - moved or swapped?
Are you sure it's not the motion work that is slipping?
Has it had a clean and oil?

Enough to be going on with!

[shutterbug]

I've seen them hang briefly at the maximum oscillation point too, slowing the time keeping.

[bangster]

Just got it.
Haven't had it open yet.
Doesn't LOOK like it's been messed with at any recent time. Great condition.

More later.

bangster

[Bill V]

You may find that the hairspring is outside of the regulator pins when you get it apart, or, I have also seen this type of movement continue to run, although slow and erratically, when the pin that holds the spring has come loose, and the hairspring is held in palce only by at the end. The regulator pins may also be open too much, allowing too much freedom of motion.

Bill

[Mike Phelan]

Good point, Bill. I was assuming that on a cheap alarm clock, the regulator would just have been bent down and slotted, or a sort of a hook rather than having two pins.

We'll see what Bang comes up with.

FWIW, most poor performance on these sorts of clock are due to the staff pivots and cup screws being worn, a subject covered many times on here.

[RJSoftware]

Good question.

I suppose the hairspring could grow weaker (rust, or general wear).

RJ

[Mike Phelan]

They are usually (but not always) non-ferrous so cannot rust, RJ, and nothing should touch it to cause wear.

Bang's best bet is to have a really close look at it, and also try to ascertain its history regarding timekeeping.