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Lift angle Gruen movements [message #10915]

Thu, 12 September 2019 17:37

Thojil
Messages: 681
Registered: May 2013
Location: Concorès, France

Gruen Master

I finally bought a timegrapher, something that was on my wish list for quite some time.

To measure the amplitude I need to set the right lift angle. Not too complicated I thought, but checking all the sources available to me I have not found them for Gruen calibers so-far. Not in original Gruen documentation nor in an internet search?

I know there is a way to determine it, but if the information is readily available it will make my life a lot easier Very Happy

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Re: Lift angle Gruen movements [message #10964 is a reply to message #10915]

Mon, 16 September 2019 03:54

JackW
Messages: 1806
Registered: May 2013
Location: Denver

Gruen Authority
General pain in the rear
Site Admin

I've not found it either, but most of the common ones, like cal 405 I believe are 52-degrees, which is the default setting on most timers.

All I know is based on hard work & writing by others. I can only aspire to augment this body of knowledge. If I am wrong it is because of my own failings. -me

"If I have seen farther it is by standing on the shoulders of giants." - Newton

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Re: Lift angle Gruen movements [message #10997 is a reply to message #10964]

Thu, 19 September 2019 18:42

Thojil
Messages: 681
Registered: May 2013
Location: Concorès, France

Gruen Master

Thanks Jack, I guess I will have to start with that number and will verify every time I have a movement finished.
Not sure if there was more variation on older movements, but I have seen a lot of different angles. My IWC cal 89 for example has an angle of only 42 degrees.

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Re: Lift angle Gruen movements [message #16209 is a reply to message #10997]

Mon, 07 March 2022 22:04

Jenneke
Messages: 1470
Registered: May 2013
Location: Netherlands

Gruen Authority

Any updates on this one? For example, are the lift angles for pocket watch movements (v-series or semithin) determined?

/vgforum/index.php?t=getfile&id=9048&private=0

/vgforum/index.php?t=getfile&id=9048&private=0

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You can only waste time if you forget to enjoy it - Loesje

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Re: Lift angle Gruen movements [message #16217 is a reply to message #16209]

Wed, 09 March 2022 04:59

JackW
Messages: 1806
Registered: May 2013
Location: Denver

Gruen Authority
General pain in the rear
Site Admin

I think the more important thing is the noise, the trace consistency, amplitude and error.

Jenneke.... Your image is what I would hope to get. Low to non-existent noise; steady trace; low beat error.

That said.... the amplitude seems quite high and makes me suspect that the lift angle is below 52. You can time the watch with a quartz movement as a refence. Figure out if you are gaining or loosing and the total it would be per day. Lower the Lift Angle on the timegrapher to an even number so that you get a close match. I don't think there are that many example of watches that are greater than 52-degrees. I'd do all this in dial up position so that you don't worry about positional error yet.

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Re: Lift angle Gruen movements [message #16222 is a reply to message #16217]

Wed, 09 March 2022 21:18

Jenneke
Messages: 1470
Registered: May 2013
Location: Netherlands

Gruen Authority

JackW wrote on Wed, 09 March 2022 05:59

Your image is what I would hope to get..

You mean, you dont want to see this Shocked

/vgforum/index.php?t=getfile&id=9052&private=0

Quote:

Low to non-existent noise; steady trace; low beat error.
That said.... the amplitude seems quite high

This pocket watch was serviced last May by a local watchmaker. That amplitude is allmost impossible. Maybe the mainspring is to strong. But would have expected overbanking signs.

So yeah, I suspect the lift angle is lower. On youtube I saw the trick with a dot on the balance wheel and wind the mainspring until it is swinging 180 degrees (to the opposite side). But timing with a quartz sounds easier. Will have a try this weekend and share the resulting lift angle.