Using an incorrect weight

[DrewV]

Just a quick question to see what y'all think about this:

I have a New Haven 30-hour Ogee that I assume would require a 2 lb. 11 oz. weight or thereabouts. Problem is that the weight that came with the clock is about a full 1 lb. heavier.

The question is: can I possibly harm the movement or induce excessive wear to the verge and escape wheel by using this heavier weight?

 

[DrewV]

Just a quick question to see what y'all think about this:

I have a New Haven 30-hour Ogee that I assume would require a 2 lb. 11 oz. weight or thereabouts. Problem is that the weight that came with the clock is about a full 1 lb. heavier.

The question is: can I possibly harm the movement or induce excessive wear to the verge and escape wheel by using this heavier weight?

 

[eskmill]

The amount of weight or force required to keep a clock's escapement running, keeping a good rate and without undue wear on the mechanism depends mostly on the condition of the works from both a design and manufacture quality and two, its maintenance condition.

Here's a quick way to find out the optimal weight required: Insert a small fisherman's scale between the cord and the weight and set the clock running. When the clock stops, the <span class="ev_code_RED">minimum</span> weight will be registered on the fish scale. That should be 80% of what's required.
fixme7111936

 

[Scottie-TX]

Well "DV" the short answer is, "no". For a short time, excessive weight won't hurt it- I'm not talking minures or hours - run it that way until you get the proper weight. It won't hurt for that short of period. No. You wouldn't want to run it that way for years. "Hurt the escapement?" Naw. The weight doesn't hang from the escapement - well, O.K. perhaps additional impulse could affect the verge in ten years. Get the right weight. Use that one til you do. Re-regulation may be necessary with smaller weight, it may run faster. Da Duffer.

 

[4piet1]

scottie answerd "Re-regulation may be necessary with smaller weight, it may run faster"this is not good the ammount off weight has notting to do with the speed of the klok.
just the length off the pendel or the coil.
abbout the weight,less is better. the movement wil not wear out so fast.why do you think your new clock has a wrong weight? try out the tip from Eckmill than you are sure that you have the right weight .
greetings piet

 

[Scottie-TX]

In theory, "FORP" - you are correct. But we don't have theoretical clocks. I'm just "Da Duffer" but I work on weight clocks daily. Don't be surprised if a change in weight MAY affect regulation. "MAY" is/was the key word here. For example I would note that springwound clocks run at different rates from fully wound to fully unwound. Hmmmmm Whut's a fusee for? Da Duffer

 

[DrewV]

Well, I tried the fishing scale method and it turned out that it only takes between 1 and 1-1/2 lb. to keep the time and strike trains running in my Ogee movement. With 2 lb. applied (30% more), they both run very strong.

Problem is that I can't get a 2-lb. set of weights (or less). Every one I've seen seems to be at least 2-1/2 lb. or more. Should I even bother searching for a lighter set of weights, or should I just go ahead and get a set of 2-1/2 lb. weights or whatever I can find that's close?

 

[Scottie-TX]

Lead weights? If they're lead, get the two an' a half pound ones an' saw off a half pound with a hacksaw. Da Duffer.

 

[ged]

If they're cast iron, Drill hole/holes in underside to reduce weight. I need to see if I can obtain small fish scale over here as my restored 8day ANSONIA Ogee has cast weights that are much too heavy,(The cord lines are so tight you could play a tune on them.)Regards, Ged.

 

[DrewV]

Naturally, I could drill holes to reduce the weight, but the point is that I would be destroying some small part of history in doing so. Something tells me that it's just not the proper thing to do.

My main question was whether or not a proper weight (2 lb.) for this clock actually exists, or if the only weights available are in the 2-1/2 to 3 lb. range?

Someone must have some knowledge of the type of weights used for these clocks and if it is typical to use a much heavier weight than what is required to actually keep the movement running. As I said, I have 2 Ogee movements that both run well on less than 2 lb., yet I've never seen an authentic Ogee style weight that weighs less than 2-1/2 lb., with the majority being around 3 lb.

 

[Richard T.]

I have 2 Ogee movements that both run well on less than 2 lb., yet I've never seen an authentic Ogee style weight that weighs less than 2-1/2 lb., with the majority being around 3 lb.

Drew,

I work in a clock shop at a local antique mall that specializes in antique clocks. We have several hundred clocks at any given time. Many of these are 30 hour OGees. Most of the weights are in the 2 1/2 to 3 pound range as you stated. I will weigh a few today and see what the average weight is. Out of all of the ones that we have I'm sure that many are original.

Regards,

Richard T.

 

[Scottie-TX]

Drew: I've had the same experience - that many weight clocks were originally supplied with much heavier weights than necessary to run it reliably. Factory supplied! Spring clocks - same thing - WAAAAY over powered. Many 8 day clocks will run nearly two weeks! Just a theory - that's all. I wonder if the factory may have done this to make the clock less finicky - that it could even run out of beat reliably. That way they'd have fewer complaints. Just a theory. I'm like you: I prefer to run mine only a small percentage 10 to 15 per cent above "run" threshold. BUT! If I'm restoring for market - resale - or customer? I use a weight SUBSTANTIALLY larger to ensure reliability. MY ogee? Not more than two pounds. Da Duffer

 

[DrewV]

Scottie, how'd you get 2 lb. weights for YOUR Ogee?

Richard: thanks for checking on those weights for me. Looking forward to the info.

 

[Richard T.]

Richard: thanks for checking on those weights for me. Looking forward to the info.

Drew,

Got sidetracked today and didn't get it done. Will do it in the AM and post later tomorrow evening.

Richard T.

 

[Scottie-TX]

NAW; My fault "DV". I was being hypothetical, as in "MY clock"? Saying "if it were MY clock?" Naw I don't have a 30 hr. Ogee. But for my weight clocks I do make my own weights for just the reason you lament here. However mine are vienna weights and are made of lead. You jest ain't gonna buy an 18oz. or 7oz., etc. weight. Da Duffer

 

[david bishop]

Drew, have you considered making a weight yourself- by using lead? You can do this by pouring molten lead into an empty food can or similar, and inserting a hook at the top before the lead solidifies. I have some info on weight of lead for a given diameter and length if you need it.

David

 

[Richard T.]

Drew,

I checked several sets of weights today and they were 2 1/2 to 3 pounds. Didn't find any that were lighter.

Regards,

Richard T.

 

[david bishop]

Well I tended to agree with Da Duffer when he said that you may experience different timekeeping rates using different weight sizes, despite all the theory.

So I did a little test last week with a 30 hour German weight -driven wall clock that I have in my possession at the mo.

The weight that came with the clock ,and I feel is original, weighs approx. 700gms. I ran the clock for 24 hours and it lost 1 min and 40 secs over that period. I then used a 420 gm weight over the same period and the clock lost 3 mins and 30 secs.To double-check, I put the original weight back on and got the same result, within a few seconds.

Although I do have respect for our smart horologist ancestors, I also experience from time to time that the theory doesn't seem to add up with the practice. I'm sure I'm not alone here!

David

 

[Allan Wolff]

The period of a simple pendulum is given by the equation T=2*pi*sqrt(L/g) for small angles, that is a small swing from center. Notice that the period is affected by only 2 variables. L is the length of the pendulum and g is the force of gravity. In reality, there are other variables acting on our pendulum like air drag and the force used to drive the pendulum and keep it going. Without them, we would have a perpetual motion machine (which does not exist.) Since we cannot get away from these other variables, the simple pendulum equation provides only an estimate of the period. The more force that is put into the pendulum to drive it, more weight as it applies to this discussion, the farther we get from the simple pendulum equation. As long as this force is constant, ie, the weight is the same, the pendulum will maintain the same period. If the weight is changed, the length of the pendulum must be adjusted to compensate (changing the force of gravity is slightly more difficult.) This is the reason spring driven clocks speed up and slow down as the force from the spring changes as it unwinds.

Recall that the equation is only good for a small angle. To see the error caused by a large angle, check out this site. If the pendulum is given a small swing, the theoretical period is very close to the experimental period. Give the pendulum a large swing and the difference between theoretical and experimental becomes much greater. Cool site!