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Replacing springs.. what is the secret?


seanc
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I have a screwdriver with the end filed, both with a pointing slot, as in the photo above, and a crochet hook slot in the side. I then push the spring into its hole, and use the same tool to hook the spring to the lever. For me though the game changer was a set of tiny drills incrementing in small steps, plus a miniature spiral drill. I then measure the spring diameter with a digital vernier gauge and pick a drill of a suitable diameter, and quite often make a new hole if the spring doesn’t want to stay put in the old hole. The spring should push fit nicely and not want to come out.  I tried various other solutions but this is the one that seems to work. I nicked the idea from this video. You see him using one of these drills at 3:35. It took me a while to find the right tools…but good ole eBay came to the rescue….

 

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As for the material: Any unwound (even used) steel string (guitar, banjo, dulcimer...) will do nicely, costs very little and comes in a wide choice of strengths to choose from. I use between 0,5 and 0,7 mm diamter type. A nice side benefit of them is that they normally come with a ball end that helps jamming them to build up the tension mentioned by Tiposx. 

 

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2 hours ago, Don Taylor said:

Does phosphor-bronze have the same aging problem as brass?

See: https://www.fortepiano.com/index.php/products-menu-item/wire-menu-item/copper-alloy-menu-item/phosphor-bronze-menu-item

 

I have bought P-B wire from these guys and made springs using something like AP James system below.  The only problem I had was that any sharp bends needed to be made slowly otherwise the wire would fracture at the bend.

 

 

 

Edited by Don Taylor
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Firstly, If s spring breaks off in it's anchor hole, then simply move a mm or two to one side and make a new hole rather than damaging the action or action plate getting the old stub out.

Secondly: I use half-hard phosphor bronze wire 0.6mm (0.025 ins) diameter. It is ready to use and beautifully consistent.

Thirdly: here are two 'hands' of spring, left and right make sure you buy or wind the correct hand, good springs have the direction of wind of the 'pig-tail' matching the hand of the spring. 

 

I found steel springs too hard to blend in with other brass springs.

 

Backing up the comment above relating to the question of brass spring durability; most concertinas have all, or a good majority of their original springs still fitted. If the average age is over 100 yrs old, and most springs are brass and are still going strong why change to a steel? I opted for phos-bonze because it was more readily available as a consistently heat treated product. Having bought a small weight of wire there is enough to stretch to the US & back. I shall be leaving yards of the stuff in my will. Any phos-bronze springs I make will see my life time out, and that of the customer too.

 

Finally, to add to Alan Day's comment about conditioning brass by cold hammering it, stretching the wire a bit also works.

 

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17 hours ago, David Barnert said:

 

My Wheatstone Hayden was built in the 1980s. Why would Steve Dickinson have used brass springs at such a late date? Should I replace them all with stainless steel?

13 hours ago, Don Taylor said:

Does phosphor-bronze have the same aging problem as brass? 

 

And are folks (David?) sure that they have brass springs and not phosphor-bronze?

 

11 hours ago, Theo said:

Phosphor bronze has a much longer working life than brass, and is also much less prone to corrosion.

 

So, then, is it likely that Dickinson was using phosphor-bronze and not brass?

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3 hours ago, David Barnert said:

So, then, is it likely that Dickinson was using phosphor-bronze and not brass?

 

The easiest way to tell is if the levers and springs are a different colour. Brass is yellow and phosphor bronze has a more coppery pinkish hue.

 

Even if they are brass they probably still have decades of life left in them.

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I’m working on an 1850s concertina at the moment with original brass springs.  One spring has failed.  There is no sign of any others being replaced.  One out of 48 in 170 years isn’t bad.

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  • 3 weeks later...

Whatever you use, make your coil size a little larger in diameter to the old originals.  That alone will dramatically increase the spring lifespan.  At a certain point, fatigue drops to near zero.  My springs are still fine after 4 million cycles, up from 10,000 of the same wire at the coil size of trad concertina springs.  While music wire steel can make fine springs, it does rust compared to that ruthless SS.  I like to keep carbon steel out of concertinas, since the wood it touches absorbs moisture from the air and is never truly “dry”.  Often the steel screws that attach hand rests on old instruments and the like are badly rusted.  Brass screws poor shear strength still leave steel as better if not great because you generally can still unscrew them.  

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  • 4 weeks later...
On 11/18/2021 at 10:03 AM, David Barnert said:

My Wheatstone Hayden was built in the 1980s. Why would Steve Dickinson have used brass springs at such a late date? Should I replace them all with stainless steel?

 

Steve Dickinson would have used brass because it's the best material for concertina springs. I find there's too much resistance in steel or phosphor-bronze.

 

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I am surprised that p-bronze should break as Don suggests, perhaps his stock was in a fully hardened state, I don't think I have ever had one break. I don't think that p-bronze gives too much resistance by making a too stronger spring, I am using 0.63mm (0.025") dia wire at half hard starting condition.

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3 hours ago, Robin Harrison said:

Chris...as Don pointed out....I find it has tendency to fracture if bent too tightly or too quickly.

     Should I simply be bending much more slowly ?

Tx

Robin, I have had a coil which broke when forming the foot no matter what, very disappointing, as it was expensive.  I had bought two at the same time and the other was fine. 

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13 hours ago, Stephen Chambers said:

 

Steve Dickinson would have used brass because it's the best material for concertina springs. I find there's too much resistance in steel or phosphor-bronze.

 

Can you clarify, please? By resistance, do you mean stiffness or non-elastic losses? If stiffness, why not just use thinner wire?

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