Mainspring barrel arbor installation skill?

[LittleWatchShop]

Reinstalling the arbor in a mainspring must be a skill that is honed over time.  I am not there yet.

It always presents a challenge to me. 

I set the barrel on a bench block with a big hole in the middle so that there is plenty of room for the barrel pivot.

If the mainspring diameter at the barrel is less than that of the barrel (as I would expect it should be...) I find it hard to get the thing to seat without a number of tries.

Today, I decided to insert the barrel sideways to expand the spring and then rotate it into place.  Still a challenge, but it finally worked.  This was a new mainspring.

The barrel went flying several times...but not too far.

Maybe the experts here can share a trick of the trade.

I did a search of the forum but did not find a discussion on this--possible I could have missed it.

[SuspectDevice]

I was thinking a hollow staking set punch would be nice to hold the barrel arbor in place while I mess with the spring.

I've been looking at staking sets recently.

[jdrichard]

32 minutes ago, LittleWatchShop said:

Reinstalling the arbor in a mainspring must be a skill that is honed over time.  I am not there yet.

It always presents a challenge to me. 

I set the barrel on a bench block with a big hole in the middle so that there is plenty of room for the barrel pivot.

If the mainspring diameter at the barrel is less than that of the barrel (as I would expect it should be...) I find it hard to get the thing to seat without a number of tries.

Today, I decided to insert the barrel sideways to expand the spring and then rotate it into place.  Still a challenge, but it finally worked.  This was a new mainspring.

The barrel went flying several times...but not too far.

Maybe the experts here can share a trick of the trade.

I did a search of the forum but did not find a discussion on this--possible I could have missed it.

It takes time and practice but slight pressure on the Arbour at an angle so the mainspring opens a bit with the angled pressure as you slide it into the hole.  It is of course over a hole on the bench block.  I should make a video on this technique 

[LittleWatchShop]

5 minutes ago, SuspectDevice said:

staking set

That is clever...I will try it! 

[HectorLooi]

What are you using to hold the arbor? Stainless steel tweezers, brass tweezers, pin vise or pin tongs?

Steel tweezers tend to slip more easily, brass is a little better. But the best method my mentor taught me was to use a barrel arbor vise. I don't think it is manufactured anymore. It looks like a pin tongs. So I bought a cheap pin tongs from Cousins and bored out the hole to grip the shoulder of the arbor. It gives a very secure grip on the arbor. A pin vise works too.

I'm sure if you look through your inheritance, you might just find a vintage barrel arbor vise. Happy hunting!

[Endeavor]

Make sure that the arbor-hook is facing exactly the "opening / gap" in between the end of the spring and first inner-coil of the spring (picture taken of internet just to show, but of course the spring has to be seated in the barrel)

While holding / pressing the arbor with brass-tweezers, I usually hold/support the barrel between my thumb, index- & middle finger; gives you far more "wiggling"-flexibility and you don't have to worry about that the arbor "stands-up". With a bit of practice and the arbor pops-in with not too much effort.

Suc6

 

Edited April 26, 2021 by Endeavor

[HectorLooi]

https://www.cousinsuk.com/product/barrel-arbor-holders?code=B0043E

I just discovered that Cousins still sell this tool. It's made by Bergeon.

[Endeavor]

If you are a "I have to have a tool for everything", go for it

Never had one, never needed one, will never need one, neither a spring-winder. 10x trained fingers do make wonders happen

 

 

[AshF]

Another trick is to rotate the arbor against the direction the mainspring is wound.  This opens up the hole slightly.

But yeah, some go in easy, some take some persuasion.  Sometimes I've had to enlarge the hole a little with tweezers, especially when using a new mainspring that might not be an exact replacement.

[LittleWatchShop]

10 hours ago, SuspectDevice said:

looking at staking sets

I inherited three sets. Never thought I would ever use them. Since I have rebooted my Dads bench, I have replaced three balance staffs. Could not have done it without the staking sets.

[LittleWatchShop]

These are all great answers!!

I looked in my inherited tools this morning...hoping...nope.  Lots of pin vises and a few slip type for balance screws, but nothing that appears to address arbors.  I think one of the pin vises could be repurposed for this, however.

 

[Jon]

An Eclipse pin vice No. 123 is what I use to grip the arbor, after that whatever the technique you use, you will never lose the arbor again. It makes fitting the arbor into the spring child's-play. Any pin vice the correct size will work, there isn't a need for any specialist tool, trust me, try it and you'll see.