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Posted

This is for sale on ebay and thinking of it for next victim.  Any idea of the age?  The plate is stamped 774.

Thank you

Charlie

812848635_5-15-20201-26-42PM.jpg.10b3c4d2b51efe0ade4048237e8a40b6.jpg

Posted

modern Hamilton looks Swiss in fact it looks a lot like the watch found at the link below. Also pay attention to the stud? One of the problems with movable studs they can get moved and yours doesn't look quite right the one found at the image below looks better. But you're going to physically look at the watch to make sure it really is where it is or is not supposed to be.

 

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&AS_1977_2

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=HAM_774

Posted

Good eye.  Looks like stud screw is missing.  I’m a beginner and can’t do anything with hair springs so I’ll need to pass.

thanks for alerting me

 

charlie

Posted

Depending on how much of a beginner you are, Lc130, it might be wise to stay away from those little baguette movements for a while. But if you do decide to challenge  yourself with their super smallness, be very careful with the balance assembly. The hairsprings seem to get tangled just by looking at them wrong. The upside is that you can usually buy such movements on the cheap. Without a doubt, due to their size, they are a challenge.

And yes, good eye by JohnR725 on spotting that missing stud screw. Even replacing those can be challenging, IIRC. One tries not to back them all the way out when removing the balance. Good luck. Cheers.

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    • Your only partially correct here. Let's look at a magnified view of the image up above. Then for a flat hairspring to function correctly there has to be a little bit of breathing room unfortunately. If you would like Better timekeeping if you get a watch with the over coil hairspring then those regulator pins are supposed to be as tight as possible but still allow the hairspring the slide. With if the pins are opened up at all you'll see a dramatic timing change based on amplitude. So in our example down below initially hairspring is basically free-floating not touching anything the effective length of the hairspring is at the stud. As the amplitude picks up at some point in time they hairspring will just tide should one pin on one swing and the other pin on the other swing. As soon as it does that it changes the effective length to being closer to the regulator pins. As the amplitude picks up more and more it's obviously touching the regulator pins more and more and the length of the hairspring shortens the watch speeds up. This is where in your video at around 16 minutes he opens up the regulator pins and the watch slows down. This is because they hairspring is no longer bouncing off either pin as much. Then because the watches running slow he speeds it up just to show that yes you could regulate the watch but now you have a problem. Because the regulator pins are much farther apart amplitude is going to have a much greater effect. Like in the image down below they hairspring is properly spaced between the pins. But if those pins are farther apart the effect of amplitude will be much greater. So he speeds up the watch to cancel out the effect of the regulator pins at the particular amplitude which was dial down then when he moves the watch to a crown position which will always have an amplitude decrease because the amount of friction on the sides of the pins now the hairspring is not touching the regulator pins as much and the watch dramatically slows down.   Let's look at the other example image. In this particular example they hairspring is actually touching the regulator pin at restWhich means the effective length of the hairspring is at the regulator pin the watch runs fast. As the amplitude picks up hairspring will lift off the PN moving the effective length towards the stud which is why the watches slowing down. As you can see is the amplitude picks up They hairspring is not centered C not getting even timekeeping and the watch is slowing even more down. But at some point in time when the amplitude gets high enough this will depend upon the watch the spacing Excedrin whatever the amplitude is will be balancing actually between the pins in the watch will of course speed up and then at some point time you reach that sweet spot where it's bouncing between the two pins but as you can see it's at a much higher amplitude. So this is why hairspring has to be properly centered between the pins and the pins have to be at the right spacing otherwise you going to get strange timekeeping based on amplitude which no matter what you're going to get a little bit of that as you do have to have a little bit a spacing. At least on a flat hairspring.  
    • My understanding is that In the Etachron system the spring is only centered n order to set the stud angle when the the pins are wide open and the regulator block in at the midway point.  After that the pins are rotated in one direction only so that the width between the spring and one of the studs is 1/2 width of the spring. This results in the spring always being closer to one stud than other one.   
    • The idea is that the spring is centred between the pins when at rest. Then when the watch is running it will oscillate equally between the pins i.e. bounce off one pin then the other, as the hairspring breathes. If the spring is only hitting one pin, then it isn't centred, and most likely the pins are too far apart. Yes, the regulator pins are there to adjust the effective length of the hairspring. The spacing of the regulator pins should not affect the amplitude.  The vertical positions typically have lower amplitude than the horizontal ones. This has nothing to with the regulator - hairspring interaction. Increased friction in the verticals sucks energy from the system and reduces the amplitude. If the amplitude is less, the breathing is less. More tim between the pins = more effective length. Depending on how well the hairspring is centred, and which direction it sags, some vertical positions might run faster than the horizontal ones, and others slower. For example, if the spring is off centre towards on pin, and pressed against it by gravity, it might never bounce off that pin => faster. At the position 180 deg. away, the spring will spend more time in between the pins => slower.
    • Thank you all for the tips and insights. I'm looking carefully at the Sherline lathes with a milling attachment. I need to figure out exactly what I'd need to get in terms of the base lathe and attachments to be able to fabricate basic parts and learn how to fabricate some of the less basic ones- like a cannon pinion. Thank you again.
    • Welkom Sebastiaan! Veel plezier met deze hobby!
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