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I've worked on pocket and wrist watches for a few years now but have only just started on clocks.
My question is, "how do you safely remove a broken mainspring in an American 8 day clock"?
I assume you just tie it up with wire but I thought I'd better ask first. The spring is broken about 2" from the loop end and there's a lot more residual power left in it than I'm used to. It bent one of the strike wheels by 90 deg when it let go so, heavy leather gloves or not, I'm not game to risk slitting my wrist just yet!
If I've no suitable hoops around for wide springs, I bend lengths of 3mm steel rod into an open ended hoop, slightly smaller than the circumference of the spring, and then push a couple over the spring.
I generally do this after winding up a spring on a mainspring winder before taking off the hook, prior to fitting back into a barrel, but it works just as well the other way around.
More difficult on solid barrels but works if careful.
I also generally wear a pair of clean leather welding gauntlets when messing with big springs.
Not a lot fazes me in life these days, but the thought of the mayhem and chewed flesh from one of those babes twanging loose is one of'em!
New springs are sometimes supplied with these hoops to keep them coiled up.
Alternatively, wrap some strong wire around the spring and twist the ends tight to hold it under pressure - do that on both sides of the spring though if it's a wide one, as it can 'cone' and twang the wire off if it's off centre!
Just occurred to me that the coils work best for refitting springs, but to get the srings out if you don't want to or can't mess with hoops, you can just pull them out if careful!
If you've some good welding gloves and a strong set of mole grips or pliers, hold the barrel in one hand, pry the end of the spring out sufficient to be able to grab it and cover it with a big piece of cotton rag.
Grab the spring end with grips, then carefully tease the spring out allowing the barrel to rotate as the coil opens.
If it does 'let go' the rag will keep the spring contained the and the gauntlet protects your hands.
Old springs are generally a tad gutless and a lot less terrifying when they're out than first assumed.
I use this method on 8 day fusee wall clocks just fine, and they Are big brutes!
Twisted wire retainer.
Thanks for that John,
I'll make up a couple of hoops for later work but the problem with this one is that it's a broken "open" spring, i.e. with no barrel.
It's currently sprung out to about 3" dia with all the slack on one side. If I try to rewind the spring the broken end will slap around as it clears the various pinions etc and do more damage to the movement.
I guess I could open a suitably sized Jubilee (hose) clip, fiddle that around the spring, re-assemble the clip and then gradually tighten it as I re-wound the spring. This should keep the spring in check and avoid doing damage to me or the movement.
What do you think?
Dick, I wondered if it was one of those open sprung jobs, not had a lot to do with them.
Can you use wire and twistlock pliers and just bind the coils up tight in a few places around the spring?
Might just hold it enough to be able to get the thing out!
If you can get at the loose end, you could also bend it back and trap it under one of the wire loops to stop it unravelling.
Heck, in desperation, you could even zap it with a MIG welder on the edges, it's a junk spring anyway, just make sure you earth the machine on the spring!
Thanks for that John,
In the end I used wire as you suggested and it came out as quiet as a lamb!
Cheers Dick, usually when springs have twanged like that after breaking, there's not a lot of grunt left in them, but always pays to be cautious!
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