What is the best pendulum amplitude?

[praezis]

I suppose OH referred to adjusting the self adjusting beat feature?

Else 10 deg as amplitude would be much too much here, as I mentioned above.

Frank

[JohnR725]

One of the problems with the original question is there a way way too many variables here. For some clocks the pendulum barely moves back and forth and that is it acceptable amplitude for that clock. Other clocks have wild swinging pendulum's practically bumping into the edge of the case and for that that's the acceptable amplitude.  

[oldhippy]

There are so many factors to take into consideration it is impossible to give a correct answer, a dirty movement will give poor amplitude the same if it is dry or the wrong oil, I won't bore with anymore. 

[Nucejoe]

 Hey guys, just googled for adjusting  clock beat.

There are more relevent articles on web than Walt Disney bul shi .

 

[oldhippy]

18 minutes ago, Nucejoe said:

 Hey guys, just googled for adjusting  clock beat.

There are more relevent articles on web than Walt Disney bul shi .

 

Yes its a minefield

[nevenbekriev]

14 hours ago, Kalanag said:

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

Well, it is weight driven and with Graham escapement. This means no problems with isocronism at all, as the torque is constant and the escapement is isochronous by itself. So adjust the escapement for minimal but reliable drop lock and see what the amplitude will be. Don't forget to lubricate the pallets.

PS There is specific behavior of the Graham escapement when changing the depth.

If the escapement is shallow (no drop lock), then it behaves as recoil escapement and the amplitude rises and frequency decreases with the depth increasing.

When the point is reached when drop lock is present, then amplitude and frequency will not any more depend on the depth increasing.  But there will come a point where the depth is so big that the mowement will be not able to work any more.

[Kalanag]

2 hours ago, nevenbekriev said:

Well, it is weight driven and with Graham escapement. This means no problems with isocronism at all, as the torque is constant and the escapement is isochronous by itself. So adjust the escapement for minimal but reliable drop lock and see what the amplitude will be...

That perfectly answers my question! Thank you @nevenbekriev!

I wondered why the clock is equipped with 2 weights of 2kg each. It obviously increases friction, amplitude and lock angle for nothing.

Edited August 20, 2024 by Kalanag

[oldhippy]

This depends on the design and gearing ratio. 

[Kalanag]

And it depends on the „reserve“ the manufacturer calculates for increased friction due to lack of service.

With half the amount of weight my clock runs still perfectly. The drop takes place at the „I“ index and the swing of the pendulum ends half way between „I“ and „II“. That is in line with the comments of @praezis and @nevenbekriev.

Edited August 21, 2024 by Kalanag

[oldhippy]

If you showed us the movement that would have helped. For example if it has maintaining power that will make a considerable difference, are the pivot holes jewelled yes or no or partly as that jewels cause less friction.    

Edited August 21, 2024 by oldhippy

[MikeEll]

On 8/19/2024 at 8:54 PM, oldhippy said:

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.   

Yep. I started my working career as a CNC machine tool programmer, not for watch or clock parts but for all manner of components, including aircraft parts.  Of course, I wouldn't have the same level of competence on 150-year-old tools compared to my CNC skillset, but that's only because those skills are no longer needed with modern techniques so you have no reason to practice them.  Some things are very similar, such as working out how to best hold a piece of material to machine it accurately, etc., or understanding how a cutting tool performs on a specific material type.  Watch and clock parts follow the same principles; they're just smaller.  I found that, while a computer can be used to design and machine a part, you still need the same level of engineering experience in the designer/operator to drive that process.  Machines allow very precise tool positioning and complex movement patterns, but it still requires a skilled programmer/operator to ensure the finished part comes out as you expect, taking into account tool wear, material flexing etc.

Where the old methods come in very handy, especially in this trade, is when you only need to repair or make one item.  If I'm manufacturing 200,000 of something, then CNC wins every time.  If I need one, manual hands-on is probably quicker if you have the skills and tools available.

Edited August 28, 2024 by MikeEll

[RichardHarris123]

54 minutes ago, MikeEll said:

Yep. I started my working career as a CNC machine tool programmer

How good are 3D scanners these days?  Could a part be scanned and only minimal adjustments made to the programme? 

[oldhippy]

When it comes to clocks that have been handmade and are of considerable value and parts need to be replaced they should and are normally made by hand in the traditional way without machines. 

[MikeEll]

2 hours ago, RichardHarris123 said:

How good are 3D scanners these days?  Could a part be scanned and only minimal adjustments made to the programme? 

scanners are really good, especially if you're scanning a part with curved surfaces etc.  On a simple part though its often not necessary to scan as you have the dimensional data available either manually, or as part of a 2D drawing or 3D model.  Its more common to use scanning to produce a model, then the model used to extract the necessary machining data.

2 hours ago, oldhippy said:

When it comes to clocks that have been handmade and are of considerable value and parts need to be replaced they should and are normally made by hand in the traditional way without machines. 

or a combination of both.

For example, if making a number of parts to different dimensions, such as shafts, toothed wheels etc, the CNC programs can be parameterised. You might supply the various dimensions for number of teeth, outside diameter etc, and the part pops out the end without much/any programming effort each time.  

Edited August 28, 2024 by MikeEll

[Kalanag]

On 8/21/2024 at 11:07 PM, oldhippy said:

If you showed us the movement that would have helped…

See the link I posted already August 20, showing my service work.

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

Edited August 28, 2024 by Kalanag

[oldhippy]

Thanks for the link. 

[Dell]

Kalanag 

I see you don’t have a mainspring winder here are plans to make one.

Dell

https://mb.nawcc.org/threads/joe-collins-spring-winder-plans.123442/