PUW 1461 Lift Angle?

[SiZi]

Hi All,

I finally received the parts to complete my PUW 1461, and I’m glad to say it’s up and running.  It is fully wound and kept aside for 24 hours after which I will wind it fully again and then rest with the Timegrapher. Before I do that, I wanted to ask if anyone here knows the lift angle for this calibre? I can’t find it online and I’m trying to avoid doing that manual exercise of figuring it out if someone here already knows that the precise LA is. 
 

Thanks as always!

Sia

[caseback]

I believe it is 55 degrees.

[RichardHarris123]

I can only find two listed, neither the correct one but both have 55⁰.

[Neverenoughwatches]

4 hours ago, SiZi said:

I’m trying to avoid doing that manual exercise of figuring it out if someone here already knows that the precise LA is. 
 

Seriously I would learn how to visualise the amplitude, once learnt and practiced a few times it can be performed in just one minute. 

[tomh207]

58 minutes ago, Neverenoughwatches said:

Seriously I would learn how to visualise the amplitude, once learnt and practiced a few times it can be performed in just one minute. 

I think Old Hippy is rubbing off on you Rich

 

Tom

[SiZi]

10 hours ago, caseback said:

I believe it is 55 degrees.

Yes I too found those but they are not the correct movement. I will go with 55 for now, and then when I come back later to reservice this watch more perfectly I’ll try and figure out the LA myself as @Neverenoughwatchesrightfully suggested .

thank you everyone, as always!

Edited December 24, 2024 by SiZi

[Neverenoughwatches]

6 hours ago, tomh207 said:

I think Old Hippy is rubbing off on you Rich

 

Tom

Lol thats not a bad thing though. I think its good to learn from all the pros, after all they do or did this for a living. 

And yes I know what you meant. Sometimes I like to keep it short and sweet...to the point, and other times I can ramble on and on, and on and on and..........

[Knebo]

2 hours ago, SiZi said:

Yes I too found those but they are not the correct movement. I will go with 55 for now, and then when I come back later to reservice this watch more perfectly I’ll try and figure out the LA myself as @Neverenoughwatchesrightfully suggested .

thank you everyone, as always!

Does your phone camera have a (super) slow motion video feature? Makes it very easy to see the true amplitude (and then adjust LA on the timegrapher). No need to draw on the balance wheel or wind to exactly 180° amplitude. 

[tomh207]

1 hour ago, Neverenoughwatches said:

Lol thats not a bad thing though. I think its good to learn from all the pros, after all they do or did this for a living. 

And yes I know what you meant. Sometimes I like to keep it short and sweet...to the point, and other times I can ramble on and on, and on and on and..........

Definitely not a bad thing, maybe even meant as a compliment 

 

Tom

[Neverenoughwatches]

47 minutes ago, tomh207 said:

Definitely not a bad thing, maybe even meant as a compliment 

 

Tom

For sure Tom for sure, I wonder how OH would have coped with me as his apprentice ? Or a more accurate question,  how long he would have put up with me ?

I make great cups of tea

[tomh207]

4 minutes ago, Neverenoughwatches said:

 

I make great cups of tea

Well, you need to get something right!

 

Tom

[Neverenoughwatches]

21 minutes ago, tomh207 said:

Well, you need to get something right!

 

Tom

mostly the important stuff, I do a cracking teacake as well

[SiZi]

On 12/24/2024 at 10:54 AM, Knebo said:

Does your phone camera have a (super) slow motion video feature? Makes it very easy to see the true amplitude (and then adjust LA on the timegrapher). No need to draw on the balance wheel or wind to exactly 180° amplitude. 

Yes, that I could do. So do I halve the total arc to determine altitude? 

[SiZi]

So for example this is the PUW fully wound. I am seeing an approx amplitude of 217.5. At this amplitude the lift angle is about 41. 
PUW 1461 amplitude

but here’s a Pobeda / Slava / Zim 2602 that I tried the same with. I am seeing an amplitude of 197, but this shows the lift angle to be 32 (which sounds off, no?). So I don’t know if I’m doing this right.

Pobeda 2602 amplitude

Thanks for helping, as always! 

[AndyGSi]

You should wind the movement until you get 180deg of oscillation.

You then change the lift angle on your timegrapher until it matches the 180Deg Amplitude.

[SiZi]

1 hour ago, AndyGSi said:

You should wind the movement until you get 180deg of oscillation.

You then change the lift angle on your timegrapher until it matches the 180Deg Amplitude.

 

 

 

I have tried this too and the results are the same about 32-34 degrees lift angle on the Pobeda/slava/zim 2602. See videos below, first one shows the marks matching up when wound to 180 amplitude, and the second one shows the movement at full wind for cross check (I see about 210 amp which was matching the Timegrapher at 32 LA when fully wound).

Am I measuring LA correctly? If yes, isn’t that a very low LA?

wind to 180 video:

full wind video:

 

 

Edited December 25, 2024 by SiZi

[AndyGSi]

Normally you'd watch the amplitude from the top.

Are you saying that mark on the balance is 180Deg for the other mark when at rest?

[SiZi]

1 minute ago, AndyGSi said:

Normally you'd watch the amplitude from the top.

Are you saying that mark on the balance is 180Deg for the other mark when at rest?

Yes I made a mark on the main plate and a mark on the balance wheel exactly 180 degree away from the main plate mark, then I slowly wound till the dot on the balance wheel and main plate overlapped as you can see in the video. 

[Neverenoughwatches]

3 hours ago, SiZi said:

So for example this is the PUW fully wound. I am seeing an approx amplitude of 217.5. At this amplitude the lift angle is about 41. 
PUW 1461 amplitude

but here’s a Pobeda / Slava / Zim 2602 that I tried the same with. I am seeing an amplitude of 197, but this shows the lift angle to be 32 (which sounds off, no?). So I don’t know if I’m doing this right.

Pobeda 2602 amplitude

Thanks for helping, as always! 

This is why the 180° amplitude marks on the balance wheel and plate work so much better.

1 hour ago, SiZi said:

Yes I made a mark on the main plate and a mark on the balance wheel exactly 180 degree away from the main plate mark, then I slowly wound till the dot on the balance wheel and main plate overlapped as you can see in the video. 

This is easy to do when there are 2 or 4 spokes in the wheel. To be the most accurate, have the balance in beat, mark the wheel edge at one spoke and the plate/bridge at the opposite spoke. Wind the movement until both marks align, then set tg lift angle to have the amplitude read 180°. For marking up I use ink and a fine oiler or for fun luminous paint.

[SiZi]

7 hours ago, Neverenoughwatches said:

This is why the 180° amplitude marks on the balance wheel and plate work so much better.

This is easy to do when there are 2 or 4 spokes in the wheel. To be the most accurate, have the balance in beat, mark the wheel edge at one spoke and the plate/bridge at the opposite spoke. Wind the movement until both marks align, then set tg lift angle to have the amplitude read 180°. For marking up I use ink and a fine oiler or for fun luminous paint.

yes in this case it was easier because it has 4 spikes so I could easily mark the opposite side as you have suggested. I still get the same reading. Just to double check, I wound up fully and took a slo mo video which I then further slowed down using an app, I placed a 360 degree protractor on the screen and tried to mark out precisely the angles. This gave me 360+45=405/2=202.5 amplitude which I then used as my benchmark on the timing machine and adjusted lift angle till I got 202.5 amp reading. It’s suggesting even lower than 32 LA. 
 

I must be doing the tests incorrectly, but I can’t tell how. I feel like I’m doing exactly what the video online and what you are suggesting. I’ll try the same tests with an Omega 620 I restored recently and see what results I get (since the lift angle on that one is well documented). I also have some more Pobeda 2602 movements I am restoring so I’ll check those too.
 

thanks everyone! 

[Neverenoughwatches]

5 hours ago, SiZi said:

yes in this case it was easier because it has 4 spikes so I could easily mark the opposite side as you have suggested. I still get the same reading. Just to double check, I wound up fully and took a slo mo video which I then further slowed down using an app, I placed a 360 degree protractor on the screen and tried to mark out precisely the angles. This gave me 360+45=405/2=202.5 amplitude which I then used as my benchmark on the timing machine and adjusted lift angle till I got 202.5 amp reading. It’s suggesting even lower than 32 LA. 
 

I must be doing the tests incorrectly, but I can’t tell how. I feel like I’m doing exactly what the video online and what you are suggesting. I’ll try the same tests with an Omega 620 I restored recently and see what results I get (since the lift angle on that one is well documented). I also have some more Pobeda 2602 movements I am restoring so I’ll check those too.
 

thanks everyone! 

Yes try the test on a movement with a known lift angle. A picture of the pallet fork might give us a clue if the LA is correct and a definition as to what LA is.

[Neverenoughwatches]

Some brands have widely varying lift angles, Omega has through its calibres a range from mid 30°s all the way up 70°.  Japanese brands also have some very low LA, I found quite a few Citizen in the low 30°s 

A simple definition of lift angle...degrees of balance wheel rotation during one lifting phase of the pallet stones/escape teeth. At the opposite end of the lever...the start to finish engagement of the impulse pin/fork. The event of escapement takes up a portion of the balance swing, which equates to an amount of degrees known as lift angle.

There is another definition....the amount of the impulse pin's movement of rotation from start to end of one escape event...but that basically adds up to the same previous definition. Looking at the shape and width of the fork slot and impulse pin shape and size may give an indication to a lift angle ?

A simpler answer as to ' what is lift angle ? '...Its just a number that we tap into a timegrapher, a criteria ( some information regarding the escapement design that it doesn't know ) that it requires from us so it can calculate and tell us how far a balance swings one way from its rest point. Something that we can already do more accurately just by watching the balance wheel. It's handy to have a timegrapher show us constant change if any but that isn't dependent on knowing the exact lift angle. So in reality knowing lift angle isn't really that important...is it ?....not to me anyway.... because I ain't designing or making a watch. 

Edited December 26, 2024 by Neverenoughwatches

[SiZi]

2 hours ago, Neverenoughwatches said:

Some brands have widely varying lift angles, Omega has through its calibres a range from mid 30°s all the way up 70°.  Japanese brands also have some very low LA, I found quite a few Citizen in the low 30°s 

A simple definition of lift angle...degrees of balance wheel rotation during one lifting phase of the pallet stones/escape teeth. At the opposite end of the lever...the start to finish engagement of the impulse pin/fork. The event of escapement takes up a portion of the balance swing, which equates to an amount of degrees known as lift angle.

There is another definition....the amount of the impulse pin's movement of rotation from start to end of one escape event...but that basically adds up to the same previous definition. Looking at the shape and width of the fork slot and impulse pin shape and size may give an indication to a lift angle ?

A simpler answer as to ' what is lift angle ? '...Its just a number that we tap into a timegrapher, a criteria ( some information regarding the escapement design that it doesn't know ) that it requires from us so it can calculate and tell us how far a balance swings one way from its rest point. Something that we can already do more accurately just by watching the balance wheel. It's handy to have a timegrapher show us constant change if any but that isn't dependent on knowing the exact lift angle. So in reality knowing lift angle isn't really that important...is it ?....not to me anyway.... because I ain't designing or making a watch. 

This is an interesting point. For me, personally, I don’t want to get too academic when it comes to amplitude or beat error or lift angles. I really just want to be able to restore vintage watches into healthy functioning timepieces. All this lift angle thinking yesterday got me wondering if I might just take a more manual approach to obscure and less precise movements like the ones I’m working on by just capturing the balance wheel on slo mo and further slow it down on the computer and eye ball the amplitude to know it’s working within a healthy enough range + or - even 10% inaccuracy. Especially considering that even with amplitude there seems to be some debate over what is “acceptable” or not. If and when I restore high end precision pieces I think I will be more particular. But for these practice pieces maybe I’ll eyeball and then test by wearing and if all is good I’ll call it a day  

I am learning so much at present, everything is so new and exciting! And I really appreciate all the help you all provide here! 

[Neverenoughwatches]

Your comments are basically the end point I was making. How deep do you want to delve into the mechanics, maths and physics of the escapement ? We're not making watches here...so not that deep, but understanding the basics are definitely needed for testing and correcting common escapement issues. Particularly when it comes to old pocketwatches that have been through the mill of escapement trial and error adjustments. There is some good books on this subject alone. 

[nevenbekriev]

Lift angle of USSR 2602 movements is 42. What seen on videos/ amplitude readings is correct. The conclusion is that for some reason the timegrapher doesn't calculate amplitude correctly. Who cares? If You know how to see amplitude, then don't mind what timegrapher shows.

Edited December 26, 2024 by nevenbekriev