Barrel arbour/arbor issue

[SteveF]

I am trying to fit a barrel arbor after fitting a new mainspring and it just will not go in! I’m sure that I have the correct sized spring but it’s like the arbor is too wide for it to just slip in. Is there a way to open up that end of the mainspring without damaging it? The only solution I can come up with is to partially unwind the spring and try and put the arbor in while it’s not under so much tension. Any other ideas?

[SteveF]

[nickelsilver]

Hold the arbor in a pin vise, insert while turning in reverse of the direction of wind- in your case that would be clockwise- you might tilt a little to get it started, but it will go in.

[Jon]

As @nickelsilverhas said, gripping the arbor in a pin vice makes it a lot easier. Remember to turn the arbor as you are fitting it in an anti-clockwise direction. You will also find slightly tilting the arbor as you fit and turn it can help

[SteveF]

Brilliant advice! It worked a treat after finding the right sized pin vise. Like a lot of things, it’s knowing the tips to make the job a bit easier.

 

Thank you!

[Jon]

1 hour ago, SteveF said:

! It worked a treat after finding the right sized pin vise. Like a lot of things, it’s knowing the tips to make the job a bit easier.

 

Good stuff! Glad we could help

[mikepilk]

I hold the arbor down with some tweezers, then using an old oiler, run it between the coil and the arbor, so that the coil opens and lets the arbor slip in. 

[VWatchie]

15 hours ago, mikepilk said:

I hold the arbor down with some tweezers, then using an old oiler, run it between the coil and the arbor, so that the coil opens and lets the arbor slip in. 

I use a Bergeon barrel arbor holder 30610 (1.0mm and 1.5mm), which is one of my favourite tools, but I can imagine running an oiler between the coil and the arbor could ease the process even more for those really stubborn situations