Lift Angle vs Amp question vs timing question

[amanbra]

To the experts of the forum can you please let me know if this logic is correct?

If the lift angle is constant, should the amplitude be the same for a given timing?

Ie two watches with a lift angle 53*

Timing both 2 SPD

Therefore the Amp for both watches should be the same or vice versa?

If not, how on earth does a timegrapher determine amplitude?

[ROLLiWORKS]

Lift angle is a set number while amplitude is measured. Lift angle are dimensions within the escapement and each movement has a specific lift angle. Amplitude is how many degrees the balance wheels spins. 360 degrees is a full circle (revolution)


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[amanbra]

Originally Posted by ROLLiWORKS

Lift angle is a set number while amplitude is measured. Lift angle are dimensions within the escapement and each movement has a specific lift angle. Amplitude is how many degrees the balance wheels spins. 360 degrees is a full circle (revolution)


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yes so between two 3235 movements where they have the same lift angle, should the amplitude be the same if their SPD are the same?

[ROLLiWORKS]

Originally Posted by amanbra

yes so between two 3235 movements where they have the same lift angle, should the amplitude be the same if their SPD are the same?

Rarely will they be the same.


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[amanbra]

Originally Posted by ROLLiWORKS

Rarely will they be the same.


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yes so this is what I noticed too, two different 3235 watches with similar spd but different amp. Mathematically / mechanically how is this possible?

Secondly a timegrapher, where all it is doing is listening to the ticks, how the hell does it know.

[ROLLiWORKS]

Originally Posted by amanbra

yes so this is what I noticed too, two different 3235 watches with similar spd but different amp. Mathematically / mechanically how is this possible?

Secondly a timegrapher, where all it is doing is listening to the ticks, how the hell does it know.

Because parts cant be made to a tolerance of +/- 0.00


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[amanbra]

Originally Posted by ROLLiWORKS

Because parts cant be made to a tolerance of +/- 0.00


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Yeah okay, then 1 last question.

timegrapher is listening to the ticks. it determines the SPD at +2 and I tell it the lift angle. How on earth does it tell me one 3235 movement amp is 280 and the other 265?

[ROLLiWORKS]

Originally Posted by amanbra

Yeah okay, then 1 last question.

timegrapher is listening to the ticks. it determines the SPD at +2 and I tell it the lift angle. How on earth does it tell me one 3235 movement amp is 280 and the other 265?

Rate and amplitude is calculated by measuring the time between tick and tock and the time between tock and tick


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[amanbra]

Originally Posted by ROLLiWORKS

Rate and amplitude is calculated by measuring the time between tick and tock and the time between tock and tick


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agreed but given the lift angle is the same and the spd is the same how is the amp detected as being different by a device only listening to ticks?

[ROLLiWORKS]

Originally Posted by amanbra

agreed but given the lift angle is the same and the spd is the same how is the amp detected as being different by a device only listening to ticks?

The time between tick and tock + the time between tock and tick. You can shorten to length one to achieve or adjust the rate. Amplitude can be a gauge of friction and trueness.

Take lift angle out of the equation. I think this is just causing you confusion. These are just the measurements of the components of the escapement.


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[ROLLiWORKS]

Maybe the answer your looking for is there are adjustments that can be made to the escapement to compensate for the difference in amplitude to achieve the same rate

Are both watches fully wound?
Also are you sure both movements are exactly the same age?


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[amanbra]

Originally Posted by ROLLiWORKS

Maybe the answer your looking for is there are adjustments that can be made to the escapement to compensate for the difference in amplitude to achieve the same rate

Are both watches fully wound?
Also are you sure both movements are exactly the same age?


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Yes purchased three months apart.

Yeah I have a missing link in my understanding. I still don’t understand how a time grapher tells me a different amp when the ticks are the same and all other settings inc lift angle are the same.

I’m fixated on the lift angle as I know this changes the amp reading.


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[ROLLiWORKS]

Lift angle communicates the parameters to the device so it knows what formula to translate the sounds from the microphone into metrics that understandable.

Lift angle is basically the distance of travel. If you drive for an hr and travel 60 miles your rate is 60mph but if the travel is 50 miles your rate is 50mph. You will want to feed the machine the correct distance.

Timing machines are basically an oscilloscope and there are parameters needed to read them accordingly. Beat rate and lift angle. Real time measurement isnt always accurate so professional devices allow us to measure over time for a true reading. Average over 1 min with 30 secs to stabilize for instance. This is measured in 5 positions.

You say ticks but like i said its tick tock tick. So imagine if 2 secs/d = tick + tock + tick

So for example.

Watch 1: tick-tock is 1.6 secs then tock-tick is adjusted to 0.4 secs to equal 2.0 secs

Watch 2: tick-tock is 1.4 secs then tock-tick is adjusted to 0.6 secs to equal 2.0 secs

Both would be +2 secs/d. Let assume tick-tock is amplitude. Then tock-tick would be adjustments that could be made to the balance wheel to compensate and adjust (regulate).

This isnt exactly how it works but it should at least break it down to some type of understandable language.

W/o visualizing the escapement its hard to explain and understand





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[amanbra]

Okay I now understand what you meant, another forum member helped explain that there are multiple sounds with in the tick that human ear hears which I think is what you mean here.

[HiBoost]

Originally Posted by amanbra

Okay I now understand what you meant, another forum member helped explain that there are multiple sounds with in the tick that human ear hears which I think is what you mean here.

I think the heart of your question comes down to this: a timegrapher can't "see", it can only "hear"... so how do you "hear" an angle**? The bottom line is you don't. The timegrapher uses internal lookup tables to convert the timing between successive sounds into an angle. It does NOT directly measure this angle. By giving the timegrapher a single parameter - the lift angle - it can then scale/adjust its conversion of the timing to the amplitude angle. But if it doesn't know how many degrees come between sound A and sound B then it has no way to calculate the total degrees of sweep.

So let's use a basic example just making up numbers. If the timegrapher has measured the time between the two sounds to be Xms and you have told it that the angle moved between those two sounds is 50 degrees, it can now go and run some math and say ok, since the escapement moved from A to B, i.e. 50 degrees, in Xms, I know it is accelerating at Y rate, and therefore I estimate it will swing out to a max angle of Z degrees amplitude. But if you go back in and say "oh, just kidding, the angle between those two sounds is actually only 25 degrees" well now that completely changes its calculation. If I tell you that I ran 500m in 10 seconds you'd calculate I was going super fast, but if I say, oh wait, I only ran 5m in 10 seconds you'd calculate a totally different, and much slower, speed.

And what the timegrapher does is estimate, to continue the analogy, how far you'd get in 30 seconds even though it only has your timings for the 10 second part (between the two sounds it hears). So in the one case it says "he made it 500m in 10 seconds, and that's coming from a dead stop, so he'll probably make it 3000m in 30 seconds" (it is non-linear due to the accel/decel of the escapement). But in the second case, it says "oh, he only made it 5m in 10 seconds, so maybe he only gets 30m total in 30 seconds". Either way, it's a calculation based on heuristics, not a directly measured stat.

This angle (i.e. the distance in the running analogy) between the heard sounds is the lift angle and it is completely baked into the design of the movement. It's not something that can be adjusted, nor does it go up or down if the movement is healthy/sick. You either enter the correct number for your movement, or, you get worthless results out of the machine.

And finally, there is no direct correlation between amplitude and spd. In general we say that a movement is healthier if it has higher amplitude, but that doesn't mean its timing is correct in that state. When my Sub has normal amplitude it is regulated to around 0 spd. When the PR is very low and the amplitude has dropped nearly 100 degrees the spd is now like -25. But what if I went in and regulated it such that spd was 0 when the amplitude was super low? Now when the amplitude was good, i.e. much higher, the spd would be way off. In general, higher amplitude should provide more consistent timing (i.e. better isochronism) and then a simple regulation should have you in good shape. If the timing is inconsistent, you'll always be chasing your tail with regulation.

** The very high end, modern Witschi machines actually do have an optical sensor that allows them to literally see the escapement and thus directly measure the amplitude angle. But 99.9% of timegraphers on this planet do not have this capability.

[amanbra]

Nah my misunderstanding came from thinking there was only one sound per tick that you hear. Appears that within that one tick there are actually three sounds which allows for amp measurement given the lift angle input.


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[HiBoost]

Originally Posted by amanbra

Appears that within that one tick there are actually three sounds which allows for amp measurement given the lift angle input.

Not to split hairs, but because it's an important point to understand, the machine cannot measure amplitude. First, there's no sound at the far end of the balance wheel swing, and second, that "turnaround point" in the balance wheel does not come at a fixed amplitude anyway. All the machine does is measure how quickly you go through the first X degrees (where there are ticks book-ending that range) and then it infers, basically approximates, how far it thinks it will go total.

This may or may not be useful:

[amanbra]

Originally Posted by HiBoost

Not to split hairs, but because it's an important point to understand, the machine cannot measure amplitude. First, there's no sound at the far end of the balance wheel swing, and second, that "turnaround point" in the balance wheel does not come at a fixed amplitude anyway. All the machine does is measure how quickly you go through the first X degrees (where there are ticks book-ending that range) and then it infers, basically approximates, how far it thinks it will go total.

This may or may not be useful:

yeah so from what I understand the sounds with in the tick allows the timegrapher to measure the velocity of the wheel at that point in time and therefore estimate the amplitude.

If there was only one isolateable sound per tick it would be impossible for the timegrapher to estimate amplitude.

[ROLLiWORKS]

Yah this topic can be a hornets nest so I was avoiding some the stickier subjects. But the OP question was how is timing the same if amplitude is different and compensation is how this is possible.



52 degree lift angle is an assumed average. Lift angle will vary on every movement even if it's the same caliber. Witschi makes a $20k device that can measure true lift angle and true amplitude using a camera. On modern movements the variation won't be much and a fraction of a degree won't won't affect the readings much. On older watches the variance can be much larger. There's a lot more complexity to timing machines than people give credit for. That's why top shops gravitate to the machines that are nearly $10k a piece. The Swiss manufacturers of these devices understand the challenges and are constantly improving methods to better understand the environment within a movement. This is where the trust lies with companies like Witschi. Timegraphers are fantastic hobby devices but don't read into them too much. Swiss makers see problems and are constantly looking for new and better ways for us to tackle and solve them. For Chinese tool makers their challenges are different. It's mainly about making tools that look like and function similar to the Genuine Swiss brands at the lowest cost possible. It's unlikely that they are calibrating timegraphers so that every one produced reads the same.



Also there not actual way for us to know how old the movement is even if the watches were purchased on the same day. Less so with the 32xx but I've seen watches a few months old with a 31xx movement that I suspect had movements that were several years old. No way of knowing for sure, but just not as clean and tidy as one would expect to see.

Originally Posted by HiBoost

Not to split hairs, but because it's an important point to understand, the machine cannot measure amplitude. First, there's no sound at the far end of the balance wheel swing, and second, that "turnaround point" in the balance wheel does not come at a fixed amplitude anyway. All the machine does is measure how quickly you go through the first X degrees (where there are ticks book-ending that range) and then it infers, basically approximates, how far it thinks it will go total.



This may or may not be useful:

[HiBoost]

Originally Posted by ROLLiWORKS

Yah this topic can be a hornets nest so I was avoiding some the stickier subjects.

Thanks for all you've shared Michael. I can appreciate how there is way more to the subject than us hobbyists can possibly know, but it's still more fun to talk about than "where are all the watches?" Haha



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[Crown & Shield]

Great stuff, many thanks to ROLLiWORKS & HiBoost for their valuable input.

[214270Explorer]

Thanks for this great information.
I had no idea of the "details" involved.
Looks as if I wold never have a reason myself to spend money for a Timegrapher.
Far too much physics going on there for me to want to deal with.
My watches all work fine anyway, and can go in for service if ever needed.