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[mselic]

I'm accustomed to lightening the button spring tension on one-row accordions that have "coil" springs, and would like to do the same on a box that has the "scissor-type" springs that sit under the key.  I'm assuming the way to do this would be to put a small bend in one of the lengths of springs? Yes, no? Problems with this approach? I've done it with Hohners, but the set-up is a little different.

[mselic]

Has nobody done this before?

[Winston Smith]

On the instruments (old junk?) which I've messed about with, it would seem that the only way to accomplish this would be as you have described. Perhaps a picture might elicit a more reasoned response from our more experienced members?

[Theo]

Yes, bending the legs is the only way I know of to adjust the spring tension. Strictly speaking it’s the pre-load, but is what alters how hard you have to press.

When I’m doing this I make small adjustments to one spring until I get the button feel I want then use that spring as a template and bend the rest of the row the same.

It’s common for each row to use a different thickness of spring wire so it’s best to do one row at a time.

[mselic]

I experimented with one spring but, by putting bends in it, I was only able to *increase* the strength of it (or perceived strength of it - a bend in one spot made the action of the lever feel heavy and sluggish). I’ve attached a photo showing the springs in question. Personally, I loathe this design because if you need to change a spring, it’s a royal pain in the ***, but it’s what’s in there, so...

Can anyone suggest where in the spring a bend might decrease the strength of it? Possibly near the coil/helix?

[Winston Smith]

I would have thought that bending the spring legs (as you have) wouldn't make much of a difference. When I've done anything similar, I've just closed the V shape of the spring. Close it up to weaken and pull it our to strengthen.
Mind you, I'm just a rough old motor mechanic blindly stumbling on!

[Theo]

Yes,  what Winston said.  Bend the leg close to the coil to bring the two legs slightly closer.  If you have increased the bend in the leg next to the lever then you have in effect moved the end of the legs further apart.

Bend it in the other direction to reduce the pre-load and soften the button feel.

[mselic]

Thank you both - that makes sense. I know that with Hohner springs putting a bend in the one spot will weaken them, and I think I was trying to make the same principle work here.

Now the next question is, would I be able to close up the springs with them still installed on the key? They’re glued in place and I’d love to not have to pry them out if possible, but simply closing the spring on itself in place doesn’t seem like it would successfully ‘close’ the spring a noticeable amount.

[Winston Smith]

I haven't come across glued-in springs. Most of the ones I've seen have a small right-angle bent into the end which anchors it actually into the arm, so that it cannot slide off and jam the lever by slipping down in between.

[Theo]

If I were to try to alter the springs in situ I would see if I could grasp the coils by placing one jaw of circlip pliers into the coil and gripping the side of the coil where the free leg emerges. Then you might be able to bend the leg at the point where it joins the coil.  That would be like adding a little to the coil.

As Winston says the fixed end of the spring is just spiked into the wood. Easy to lever out with a flat tool slipped under the leg.

[mselic]

I haven't come across glued-in springs. Most of the ones I've seen have a small right-angle bent into the end which anchors it actually into the arm, so that it cannot slide off and jamb the lever by slipping down in between.

Most of the ones I’ve seen are actually stapled in place as well!! Depending on the design of the spring, putting them back in without the little staples to hold them down renders them poorly functional (and the staples are a serious bugger to install!) The ones on this box are a little different in that they seem to have several bends in them already keeping the spring in place without the need for a ridiculously teenie, tiny, wee little staple that would give watchmakers a run for their money!

Now, if these were built with coil springs, one would need only to remove the keyboard to have unfettered access to springs which would then be easily adjusted, replaced, etc...I’ll stop griping about this eventually, I promise..

[mselic]

As Winston says the fixed end of the spring is just spiked into the wood. Easy to lever out with a flat tool slipped under the leg.

Yes, but I’ve sometimes seen them glued in place in addition to being ‘spiked’.

[mselic]

Just wanted to share the I achieved what I wanted by closing the V-shape of the springs as both Theo and Winston described.  Removing the springs from the wood was required.  Worked like a charm!