Mainspring for Luch 2209 movement

[JohnR725]

8 minutes ago, alx2021 said:

GR2918DB (same height) and it kicks healthy 300+.

Some watch companies get excited when amplitude goes over 300°.

Then size specifications between Your two mainsprings is interesting.

Other than a little bit a difference of length the 2918 is actually lighter in strength.

34 minutes ago, alx2021 said:

Here is a pic of a new GR2946DB. Looks weak to me.

You can't visually look at a mainspring and see if it's week. You can look at a mainspring and see if you like the shape of it but? If you take a blued steel spring out of the barrel and it barely opens up that would look bad. Then today unfortunately mainsprings don't always seem to have a nice desirable shape when they come out of the package. So while yours looks a little bit set if it runs the watch for more than 24 hours watch keeps time you're fine.

For instance below is a picture of two brand-new mainsprings. I definitely would prefer the top one over the bottom but they're what came out of the package and both of them went into watches as far as I know they worked fine. But generally like to see the upper one little bit of that curve if they do their curvature right the mainspring power supposed to be a little more even.

 

 

 

 

[Neverenoughwatches]

54 minutes ago, JohnR725 said:

Some watch companies get excited when amplitude goes over 300°.

Then size specifications between Your two mainsprings is interesting.

Other than a little bit a difference of length the 2918 is actually lighter in strength.

You can't visually look at a mainspring and see if it's week. You can look at a mainspring and see if you like the shape of it but? If you take a blued steel spring out of the barrel and it barely opens up that would look bad. Then today unfortunately mainsprings don't always seem to have a nice desirable shape when they come out of the package. So while yours looks a little bit set if it runs the watch for more than 24 hours watch keeps time you're fine.

For instance below is a picture of two brand-new mainsprings. I definitely would prefer the top one over the bottom but they're what came out of the package and both of them went into watches as far as I know they worked fine. But generally like to see the upper one little bit of that curve if they do their curvature right the mainspring power supposed to be a little more even.

 

 

 

 

It would be nice to think it possible that a mainspring could be reset to its original shape as new then retempered to retain that shape, unset it so to speak. 

https://www.thenakedwatchmaker.com/making-mainsprings#:~:text=The modern mainspring%2C made from,output than was originally developed.

Edited July 13, 2023 by Neverenoughwatches

[alx2021]

2 hours ago, JohnR725 said:

For instance below is a picture of two brand-new mainsprings. I definitely would prefer the top one over the bottom but they're what came out of the package and both of them went into watches as far as I know they worked fine. But generally like to see the upper one little bit of that curve if they do their curvature right the mainspring power supposed to be a little more even.

BTW. I don't have a photo but "weaker" in specs GR2918DB has this end curve. 

[mikepilk]

3 hours ago, alx2021 said:

For the record. I have couple Luch with 2209 movement I was working on. I've used new GR2946DB mainsprings from Cousins and couldn't reach any amplitude over 240 with them. Instead I've tried GR2918DB (same height) and it kicks healthy 300+.

Here is a pic of a new GR2946DB. Looks weak to me. I guess I'll be checking new mainsprings for older movements from now on.

 

Looks fine to me

[JohnR725]

6 minutes ago, alx2021 said:

BTW. I don't have a photo but "weaker" in specs GR2918DB has this end curve.

The problem with manufacturing is there is no specifications for what the spring should look like.

 

1 hour ago, Neverenoughwatches said:

It would be nice to think it possible that a mainspring could be reset to its original shape as new then retempered to retain that shape, unset it so to spea

It would be really nice  if brand-new mainsprings were manufactured to the specifications that we expect. In other words they don't look like they're partially set out of the package they have the proper back curve. Which unfortunately most people don't grasp what the spring looks like as a just somewhat of a package. It's only when you doing watches with the peculiar ends That it is taken out of the ring and contemplate why does it look like crap but it's what I got so it's what I'm going to use.