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Beat error


BUSAKAZ

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Hi all, I'm a bit confused as to why the beat error is so far out when the pallet fork is dead center to the banking pins and the balance is at rest under no tension, can someone please explain.

thanks kaz

Ps I can't seem to regulate the rate neither,I have demagnetize it three times and the hair spring isn't touching the cock neither.

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30 minutes ago, frenchie said:

Just a guess: Low amplitude and running fast = not enough power to the train (or lots of power being wasted, ie dirty jewel holes)...

 

it's had a new main spring and the train runs freely without the Pallet fork in, a bit confused :wacko:

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I think beat error is your least problem at the moment. 5ms can be better, but is not an issue.

No wonder regulating is difficult: your hairspring is not concentric in the pins area, and it has a kink at the regulator pins. Also the pins are too wide apart, space must be minimal here (unfortunately this will speed up the rate).

Yes, as mentioned before, amplitude is much too low (which esc. angle did you choose?)

Regards, 

Frank

Edited by praezis
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30 minutes ago, praezis said:

I think beat error is your least problem at the moment. 5ms can be better, but is not an issue.

No wonder regulating is difficult: your hairspring is not concentric in the pins area, and it has a kink at the regulator pins. Also the pins are too wide apart, space must be minimal here (unfortunately this will speed up the rate).

Yes, as mentioned before, amplitude is much too low (which esc. angle did you choose?)

Regards, 

Frank

do the pins have to be nearly touching at the bottom then ?

it's on automatically and came up at 52deg as do all of my pocket watches, where do you see the kink after the pins or between the pins and the stud.

thanks for your help

 

 

 

 

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Edited by BUSAKAZ
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Hi,

the kink I see in your 2nd picture, maybe I am wrong.

Pins are better, but still not close enough - and they should be parallel. Difficult with these rather thick pins, I know. But these are subtleties that you can fix later.

Main issue is the low amplitude.

52° is ok for nearly all wrist watches. Pocket watches have smaller angles, about 40°. Bad news: Your amplitude is probably 20% lower than your display shows, as the esc. angle was set too high.

Regards, Frank

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8 hours ago, praezis said:

Hi,

the kink I see in your 2nd picture, maybe I am wrong.

Pins are better, but still not close enough - and they should be parallel. Difficult with these rather thick pins, I know. But these are subtleties that you can fix later.

Main issue is the low amplitude.

52° is ok for nearly all wrist watches. Pocket watches have smaller angles, about 40°. Bad news: Your amplitude is probably 20% lower than your display shows, as the esc. angle was set too high.

Regards, Frank

I don't think they should be parallel if you look at the second picture at the top of the pins there is a clear gap, I will get them closer and see what it does then, I can't see a kink though and I will also try 40 deg.

thanks for your help

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I have noticed this too i.e. the roller impulse pin seems in the middle at rest but when running & put on a timing machine the beat goes out. I guess there is some sort of uneven bounce happens & that is what throws it out but i am not sure & I have just adjusted the beat. 

The beat error on your watch will have to be adjusted by moving the hairspring collet & Mark has a vid on this. The rate is adjusted buy in effect shortening or lengthening the hairspring. This works by the spring vibrating in-between the regulating pins so if the rate is not changing then the spring is not in-between the pins. It is worth noting that at rest the hairspring should be in the middle of the regulating pins & not touching them. 

PS. Looking at your pics there does not seem a lot wrong with the hairspring shape. Another thought is it a new hairspring fitted ? if so it could be too short.
 

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I have a video how to determine the correct lift angle. You have to notice the amplitude and set the lift angle on the timing machine until it shows the real amplitude.

It seemed to me that the overcoil is higher at the regulating pins than the stud. This wont allow the overcoil to wobble between the pins and bend the hairspring. Try to elevate the stud a bit.

Check also again that the overcoil is not touching the cock. Just twist the balance to ~300 deg. amplitude with a toothpick. This is suspicious, since YOu have both low amplitude and beat error despite the properly positioned impulse jewel. 

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3 hours ago, szbalogh said:

I have a video how to determine the correct lift angle. You have to notice the amplitude and set the lift angle on the timing machine until it shows the real amplitude.

It seemed to me that the overcoil is higher at the regulating pins than the stud. This wont allow the overcoil to wobble between the pins and bend the hairspring. Try to elevate the stud a bit.

Check also again that the overcoil is not touching the cock. Just twist the balance to ~300 deg. amplitude with a toothpick. This is suspicious, since YOu have both low amplitude and beat error despite the properly positioned impulse jewel. 

top man I will give it a go as soon as I can.

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22 hours ago, clockboy said:

Determining the lift angle & setting the timegrapgher to correct setting will only make a marginal difference to the readings. I very rarely bother to adjust from the standard of 52 deg.

you are correct changing the lift angle made absolutely no effect but what I have done is closed the pins in a bit more and I had the train bridge to tight so slackened it off and the amplitude has now shot up.

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also I straightened up the spring from the pins to the stud so I am now thinking how to get the rate down and I is definitely not touching the cock, but it is getting better and it is still the original hairspring.

still need help, it a southbend 411 12size but if anyone knows the lift angle that would be good.

thanks for your help guys

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If the bridge is causing the hairspring not to swing either the bridge is bent or the balance staff is too long (marginally).
I strongly suspect a new hairspring & balance has been fitted but the hairspring is just to short. There just does not seem enough of the hairspring remaining to reduce by 130 s/d. This PDF explains better than I could.

Hairspring choosing.pdf

 

 

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39 minutes ago, clockboy said:

If the bridge is causing the hairspring not to swing either the bridge is bent or the balance staff is too long (marginally).
I strongly suspect a new hairspring & balance has been fitted but the hairspring is just to short. There just does not seem enough of the hairspring remaining to reduce by 130 s/d. This PDF explains better than I could.

Hairspring choosing.pdf

 

 

I think I have found the problem, if you look at the hairspring at three o'clock the spring is touching what do you think.

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Also, you have not mentioned whether or not the movement has been fully cleaned and lubricated? 

A reading like yours generally points to the escapement, in which case a full examination of the balance assembly (bridge, staff, balance wheel truth and poise, roller table, impulse jewel, hairspring, collet, regulator pins, stud), pallets, lever, escape wheel and jewels must be conducted to locate the error. 

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5 hours ago, JMElam said:

Also, you have not mentioned whether or not the movement has been fully cleaned and lubricated? 

A reading like yours generally points to the escapement, in which case a full examination of the balance assembly (bridge, staff, balance wheel truth and poise, roller table, impulse jewel, hairspring, collet, regulator pins, stud), pallets, lever, escape wheel and jewels must be conducted to locate the error. 

fully cleaned and oiled with moebius 8000

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