Sometimes springs are bent in the general direction that makes them work but not in the best direction for the key. Not so likely to make much difference but worth checking anyway.

Make absolutely 100% sure the key doesn't stick in any way.I mean the hinge of the C# key. Sometimes a key will stick only very slightly and only in some positions, possibly just before it closes. Then there is actually not enough force from the spring closing it.

Maybe that specific spring is better to put on its cradle while mounting the key. Some springs have to be on their limit and putting them on their cradle after the key is mounted will return them a bit. Sometimes those extra 1 or 2 mms the spring has to move when doing this is critical.

You (i.e. your repairer) can try an even larger spring. IMO the C# especially feels pretty awful on those old saxophones so increasing to a thicker and stronger spring would make it feel even slightly worse. You have to decide if you can accept that. Unless the spring is already very long for its diameter, then one size thicker spring might feel good too, though small chance. A more drastic repair would be to change the location of the cradle.

Just in case make sure that the C# doesn't have any leak. Especially if it's an old pad sometimes they can have tiny leaks around them which are hard to see, or a very deep seat that makes it hard to see.

Another possibility is that maybe you accidently slightly touch the C# lever when you play Bb.

 

Thanks...

The thing is, we've got the thickest spring that will fit in there. We're maxed out and the tension is still weak.

The C sharp key is otherwise not being touched when playing low Bb.

And it only blows open when I play pretty loudly.

 

The thing is, we've got the thickest spring that will fit in there. We're maxed out and the tension is still weak.

Maybe I wasn't clear. I think you mean the same as what you wrote in your first post, that you tried the biggest spring that fits inside the current hole, yes? What I meant was to enlarge that hole slightly to allow fitting a spring one size bigger. Did you try that? The rest of my post re the feel of the key with a bigger diameter spring refers to doing this. So whether this would affect the feel etc. too much is something for the player and the repairer who is actually doing it to decide.

In addition you don't say whether you know for sure that the biggest spring that currently fits is really at the maximum tension, for the reason I explained i.e. putting the spring in its cradle only after the key is mounted. This is not likely the problem, but still possible.

 

The 10M low C# key can be troublesome, given the single-piece design and the way it's sprung, but any problems are usually down to free play in the key barrels or a poorly seating pad. There's not much room for error in the design - but I have never needed to increase the size of the spring used.

Have you tested the pad with a cigarette paper, all round?

http://www.shwoodwind.co.uk/HandyHints/LeakyPads.htm

Regards,

 

1. it is easy to ream that hole out to take a larger spring. Grind the end of the new spring at a steep angle and use that spring as a reamer.

2. As Clarnibass says, a thicker spring may solve your problem but introduce others, such as a more sluggish action.

3. The force exerted by the closing spring can be increased by reducing friction where the Low C# key meets the low C# lever. For example teflon laminated to the silencing material, and eliminating the dent that can develop in the silencing material. Any metal surface involved should be buffed.

4. This friction can also usually be reduced by altering the geometry at this lever/key connection, so that the contact point of the junction(at the time when the pad closes) lies on plane containing the hinge of both the key and the lever. Also by re-shaping to move the contact point closer slightly closer to the lever, although this will have repercussions for the travel of the key.

5. Make sure the C# pad is in top condition and the tone hole is level.

6. "It's just that when playing the low Bb, the G sharp key is no longer applying downward pressure to the C sharp key. " The G# lever should never apply downward pressure to the C# key, otherwise G# would not fully close and seal.

7. Modern day steel springs break easily when their tensioning is pushed to the limit. A top quality stainless steel spring (the type form Kraus, not Ferrees) applies just as much force as steel, but is far less likely to break when highly pre-tensioned.

8. Make sure the spring is not jamming in any way in the spring cradle.

9. Make sure the spring is tensioned in a direction that is most effective, i.e. the direction that the cradle is travelling in at the moment the pad closes.

10. I may have overlooked other factors that would be apparent on seeing the instrument.

For C# to close reliably without the key having a sluggish action requires that the manufacture/technician attends to all contributing factors.

 

3. The force exerted by the closing spring can be increased by reducing friction where the Low C# key meets the low C# lever. For example teflon laminated to the silencing material, and eliminating the dent that can develop in the silencing material. Any metal surface involved should be buffed.

Just to avoid the OP becoming confused - the 10M has a single-piece low C# key, there's no separate lever/key.

One other possibility that springs to mind ( excuse pun ) is that the 10M C# key has a guide pillar - about halfway along?
If the key barrel is binding on this support it will cause problems. It has to be checked with the key sprung - slide a cigarette paper under the key barrel, move it up over the guide and operate the key. Tug the paper out slowly as you do so. If it binds at any point it usually means a bent key barrel - and you will need to have it sorted out.

Regards,

 

Everything is moving smoothly and freely. It's really just an issue of the odd way the spring comes out of the post. So yes, on the next visit with my tech, I think we will need to enlarge the hole and try a larger spring. I'm not so concerned about the action. (I'm getting to the point where I no longer feel the need to play fast anyway!) Correcting the key from blowing open is more important.

Thanks everyone...

 

I have a very similar problem in a 60's 16 M. Did you get this sorted?

 

Yes, I think it was a matter of getting the spring in there in just the right way given an issue with the way the hole affected the angle if the spring. It's been working fine since and I'd actually forgotten about it!