Mainspring adjustment

[IFELL]

Hi all,

I had to replace mainspring on this ETA 2782 but after I fitted it into the barrel I found out that the end of it does not engage with the hook on the barrel arbor. 
I guess this can be fixed by adjusting the final turn of the mainspring so my question is: what tool to use? I found variety of pliers on Cousins but I'm not sure which are suitable for this kind of job.

Thanks for your advice and suggestions.

 

[clockboy]

If you close the final curl make sure you have a round centre support or it will collapse. I use a Balance Bridge Holding Tool which helps me gauge the progress.

[IFELL]

So just normal flat pliers and the center round support should do it?

Thanks.

[vinn3]

there are "  rounding pliers" .  Should that spring end anealed  (softened).  vin

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[clockboy]

I use large hairspring tweezers which have a nice concave & convex shape.

[Watchfixr]

Be careful not to put a straight line bend at the point away from the arbor end where the slot for the barrel arbor is cut from the mainspring. It will almost certainly fail when wound a few times. That area needs to be a smooth curve to maintain strength.

I have an assortment of piano wire I use for re-pivoting clock arbors and I select progressively smaller diameter pieces to use as a mandrel when bending the curve. Round bar stock works well for larger barrel arbors, but lately it seems all I get is 5''' ladies bracelet watches.

[jdm]

On 11/13/2017 at 3:54 PM, clockboy said:

I use large hairspring tweezers which have a nice concave & convex shape.

Where to find these?