What is the best pendulum amplitude?

[Kalanag]

My Kieninger wall clock has an amplitude indicator as shown here:

The clock has 82 ticks per minute.

Could the clock experts tell me, what amplitude the pendulum should have? 

[oldhippy]

I can't tell you as I would need the clock. But you can do it yourself by doing this.

 

To determine the amplitude of a simple pendulum, you can use the following steps:

Measure the length of the pendulum string or rod from the pivot point to the center of the pendulum bob.

Displace the pendulum bob to one side and release it, allowing it to swing freely. Measure the angle between the vertical line and the pendulum string at the maximum displacement, which is the amplitude.

You can also use the formula for the period of a simple pendulum:

[watchweasol]

Hi.  It’s as O.H. Says  and is explained in De Carles book. In a perfect situation ar rest the pendulum should be dead center on the mark. Once the pendulum is started and reaches its natural rhythm as governed by the escapement the amplitude should measure the same both sides. You quite often find them off center to compensate for a badly adjusted escapement but that’s only on the indicator the amplitude/ period is the same within the clock.

[RichardHarris123]

For fun, using the rate I  estimate that the pendulum is circa 46 cm. I'm awaiting being miles out, hehe. 

[Neverenoughwatches]

57 minutes ago, oldhippy said:

I can't tell you as I would need the clock. But you can do it yourself by doing this.

 

To determine the amplitude of a simple pendulum, you can use the following steps:

Measure the length of the pendulum string or rod from the pivot point to the center of the pendulum bob.

Displace the pendulum bob to one side and release it, allowing it to swing freely. Measure the angle between the vertical line and the pendulum string at the maximum displacement, which is the amplitude.

You can also use the formula for the period of a simple pendulum:

Always good to learn something from you OH , never thought about this before, the amplitude seems quite simply is just the angle of swing of the pendulum from rest . The same portion of a full circle that is travelled with a balance wheel. Haha I've learnt something about clocks yey

I have a question, and before i ask its no offence or a reminder that might apply to anyone of a particular age because we're getting older. I understand that some folk have a preference for watches , pocket watches or clocks and some like all of them. For those that maybe had a watch preference first is there some kind of transition for some that takes place with age, eyes and hands not being as keen and nimble as they used to be. I asked WW a similar question when i first joined. 

54 minutes ago, RichardHarris123 said:

For fun, using the rate I  estimate that the pendulum is circa 46 cm. I'm awaiting being miles out, hehe. 

I can see you're desperately trying to hold on to your title Rich , give it up mate I'm snapping at your heels , i guess at 7 feet long

[praezis]

1 hour ago, oldhippy said:

Measure the angle between the vertical line and the pendulum string at the maximum displacement

How?

[oldhippy]

With me it was a case I found clocks more interesting. The workshop was well equipped and we always had loads of different types of clocks many high quality such as English Bracket, Longcase and loads of French clocks and carriage clocks.   

[Neverenoughwatches]

6 minutes ago, oldhippy said:

With me it was a case I found clocks more interesting. The workshop was well equipped and we always had loads of different types of clocks many high quality such as English Bracket, Longcase and loads of French clocks and carriage clocks.   

I wondered if it was a case of issues being more easily identified without having the visual restriction of dealing with such small parts as in watches.  I remember visiting a small antique shop a few years ago in north Yorkshire when i wanted a 30's mantle clock for my fire surround shelf. Across the road they had their workshop, i told the owner that i wouldn't mind buying anything that didn't work as I'd love to have a go at fixing a simple clock. He said if i decided to take it up as a hobby and got good at it that I'd never be out of work, he had a customer waiting list of 3 years, that was just a simple village antique shop and clock repairer. His comments propelled me to where i am today.  I'll post his contact details so forum members can make their complaints to him

[watchweasol]

Hi @Neverenoughwatches with me as you know I started on watches but found clock just as interesting and do what ever can

me my way watches , clocks, 400day clocks you name it I did it as I am now in my 81st year is still use the same philosophy even Timex  and quartz watches some people hate them some love them I found them interesting .and still doing them. Tools I love and information got a lot on watches ,clocks etc.  mad I know.

[oldhippy]

watchweasol, Timex  and quartz watches I wouldn't touch the things. We would send those horrid Timex things back to Timex, as for quartz I would replace batteries but fiddling around with bits of plastic no thank you. Give me a 100 year old clock anyday. 

[Neverenoughwatches]

1 hour ago, watchweasol said:

Hi @Neverenoughwatches with me as you know I started on watches but found clock just as interesting and do what ever can

me my way watches , clocks, 400day clocks you name it I did it as I am now in my 81st year is still use the same philosophy even Timex  and quartz watches some people hate them some love them I found them interesting .and still doing them. Tools I love and information got a lot on watches ,clocks etc.  mad I know.

No its not mad WW, its passion for something you enjoy doing. Something that almost everyone here will understand. 

1 hour ago, oldhippy said:

watchweasol, Timex  and quartz watches I wouldn't touch the things. We would send those horrid Timex things back to Timex, as for quartz I would replace batteries but fiddling around with bits of plastic no thank you. Give me a 100 year old clock anyday. 

I can see your side of it OH, plastic and rivets dont exactly spell out quality next to the craftsmanship of a well made clock. All timepieces have a place ( and i know whats coming ) and everyone's passion lays somewhere different. 

[Kalanag]

Many thanks so far!

Unfortunately, I might have asked incorrectly. My question was related to the desirable amplitude a clock should have. As with watches, the amplitude depends on the service status of the movement and the driving force (the size of the driving weight or mainspring). Watches need a minimum amplitude to run well. Are there similar recommendations for clocks?

[praezis]

35 minutes ago, Kalanag said:

Unfortunately, I might have asked incorrectly

No, you didn‘t. I was surprised about the replies.

Long version: You could fill books with the correct answer.

Short version: for your pendulum about 1 … 1.5 degrees.

After the audible drop of the escape wheel the pendulum shall move another (roughly estimated) 0.5 to 1x the same distance.

Frank

[Kalanag]

@praezis Perfect!  

[JerseyMo]

rivets?  I'm still waiting for proof of this!  I looked through all of these and not one single riveted together movement. maybe it is just a myth

 

[Neverenoughwatches]

18 minutes ago, JerseyMo said:

rivets?  I'm still waiting for proof of this!  I looked through all of these and not one single riveted together movement. maybe it is just a myth

 

 

20 minutes ago, JerseyMo said:

rivets?  I'm still waiting for proof of this!  I looked through all of these and not one single riveted together movement. maybe it is just a myth

 

Haha you've just blown up a myth Jersey Mo, some quartz have them though.  I wasn't referring to Timex , I've only opened up 4 but i didn't find any either. 

[oldhippy]

What do you mean by rivets JerseyMo?

[watchweasol]

When you look at a 100 yo clock and marvel a5 the quality of the workmanship given the tools they had and mast likley had to make by hand, one thing goes through my mind, how long did it take for them to finish the clock, a year maybe two but if of or more men make the same clock probably six months. One the plates , one the escapement , one or two cutting wheels etc. now equate that with todays technology, to make the machine tools etc six months, top and bottom plate ma+hined and drilled  minutes, the skill in todays work force is the toolmakers and CnC operators. Even the humble Timex took toolmakers to make the dies to punch and drill the plates. The point I am making is the skills are still there just changed. So each watch produced be it either old or new has its merits, depends on your point of view. A lot of watchmakers don’t touch the low end or working class watch as there is no money in it  any more.once upon a time they would re staff a smiths empire for a fiver and make a profit, you used to get a packet of three staffs not any more.  Times change but not peoples attitudes.

[oldhippy]

Its more technical these days you have computers that design the movements ok humans have the input, but they couldn’t make the parts by hand using the tools of say 150 years ago.   

[nevenbekriev]

4 hours ago, Kalanag said:

Many thanks so far!

Unfortunately, I might have asked incorrectly. My question was related to the desirable amplitude a clock should have. As with watches, the amplitude depends on the service status of the movement and the driving force (the size of the driving weight or mainspring). Watches need a minimum amplitude to run well. Are there similar recommendations for clocks?

Well, there is not simple answer here.

First of all it depends on the escapement type. If it is like Graham or Brocot types with no recoil, then smaller amplitude means better isochronism. Of course, I mean when clock is spring driven and no fusee or other spring torque equilising.

If it is Swartzwald type with recoil, then best isochronism is achieved with certain amplitude, which usually is not small.

The amplitude mainly depends on the escapement depth and  on second place on the torque. If the depth is small, the amplitude is small and the pendulum is forced to oscillate much faster than it's own period. The rate strongly depends on the torque and with the torque decreasing, the rate decreases too and is getting closer to the own oscillation period of the pendulum.

Increasing of the depth leads to increasing of amplitude and getting the rate closer to the own pendulum period regardless of the torque, and there is a depth where relatively isochronical work is achieved. But depth can't be increased more than the one where the movement is not able to work any more. And with the wear of the escapement, the possible depth decreases. So it is a problem to adjust the depth in movements with worn escapement (wheel teeth and anchor arms with deep traces of wear)

Amplitude is different when measured in angle - the long pendulums have smaller amplitude

The scale under the pendulum tip on the picture should actually indicate the reserve - 2 weeks, one week and then wind the clock again. But, it is not so reliable or something obligatory...

[Kalanag]

8 hours ago, nevenbekriev said:

Well, there is not simple answer here.

First of all it depends on the escapement type. If it is like Graham or Brocot types with no recoil, then smaller amplitude means better isochronism. Of course, I mean when clock is spring driven and no fusee or other spring torque equilising...

My clock has a Graham escapement and is weight driven. Does that mean that a low amplitude is preferable?

https://www.watchrepairtalk.com/topic/22546

Edited August 20, 2024 by Kalanag

[oldhippy]

It might have a  self-adjusting beat feature. It should be around ten degrees side to side. I had to look this one up, so I cheated.  

[watchweasol]

Is not cheating O.H. It’s expanding your knowledge.  It’s probably somthing you knew and did automatically when setting up a clock at work without thinking.

[Kalanag]

59 minutes ago, oldhippy said:

It should be around ten degrees side to side.

Ten degrees side to side equals about 10cm side to side imho. That seems to be too much! The drawing I posted above indicates about 3cm.

Edited August 20, 2024 by Kalanag

[oldhippy]

I did say I looked it up. Look on the net and see what you can come up with