creepy springs

[prtarrell]

On  this 1978 stage 88 the tuning springs of the utmost upper notes (85ish - 88) are creeping toward the end of the tine when struck causing the pitch to go way flat.  The tine wire increases in diameter in this area.  I've thought of a few possible solutions:   forget the last octave,  don't tune at all,  bubble gum,  wood glue,  sping tine glue,  saliva/rust.  Open to suggestions while listening up.

[suitcase'81]

have you tried bending the spring ?
so that the spring has a little angle in it.
this way it will have a tighter grip on the tine.

[Rob A]

^^ This is the way to go. Remove it from the tine first obviously.

[Ben Bove]

When I have run into this problem in the past, it's that the harp's strikeline needs to be readjusted.  Problem is that something has settled internally, so now the hammers-to-tine relation in the high register is off, and now the hammers are actually striking the springs when they're tuned in pitch.

The problem is that there's such a tiny distance where the hammer can strike the tine between the block and spring so it is a critical dimension in the high register (relatively).

If you want to fix, it will involve resetting the strikeline which is somewhat invasive... you have to reattach the harp when you get the right spot so you may need to remove the piano from the case as suggested in the manual, or you can just drill through the metal harp supports and reattach that way.  But here's what to do to check it:

Detach the right side of the harp so you can slide it around.  Unscrew the big phillips screws holding the harp down on the right side, but on one of the left screws - only loosen it about half-way, leaving it still in position.  Then, completely unscrew / detach the swivel brackets from the sides of the harp (phillips screw and nut with washers).  You should now be able to move the harp around while it's pivoting on one of the left big screws.

Tune the high register notes to the proper pitch, then locate the spot where they are struck without the hammer knocking the spring down.

After you find that spot, mark where the harp is with a sharpee, and then you'll have to reattach the harp.  Again, you might want to follow manual on this site about resetting strikeline and reattaching harp.

[suitcase'81]

Bjammerz is probably right.
(I wouldn't dare question his expertise.)
But,
before you take it apart and start fiddling with strikeline adjustments
I would check and see if the hammer IS actually hitting the tuning spring
when in tune.
just to make sure this is the problem.
if not:
bend the spring.

[prtarrell]

There were a couple of hammer tips  hitting the springs.   I was able to eliminate this by removing the tone bar clip, requiring the spring to be moved toward the tine end when in tune. On another note I clipped off half a coil of the spring and rotated it so the hammer didn't hit.  I didn't have to relocate the harp. Thanks for all the useful suggestions.             440 Phil