A0 hammer not releasing cleanly ?

[genaa]

Hi Folks,

The A0 hammer on my Kawai upright is not releasing cleanly and instead rests against the strings. Is this something I might readily be able to adjust myself, if approached carefully?

It appears that the top of the jack is not sliding cleanly off the buckskin (or equivalent) on the butt. Compared to the adjacent key, the letoff button is not being reached by the toe of the jack as well, meaning that the spring between jack and whippen is not being compressed as much. It seems the letoff needs adjusting a little I think?

Any advice welcomed - and no - I don't intend taking on any more than I could reasonably be expected to, and don't in any way fancy myself as a piano tech in the making before anyone suggests a denigration of your fine skills it's just that my tuner lives a long way away, the piano is hopefully about to be sold etc etc.

[PianoGuy]

It appears that the top of the jack is not sliding cleanly off the buckskin (or equivalent) on the butt. Compared to the adjacent key, the letoff button is not being reached by the toe of the jack as well, meaning that the spring between jack and whippen is not being compressed as much. It seems the letoff needs adjusting a little I think?

Correct.

I thought this one had been written off and replaced? The damp conditions that the piano has suffered can cause a swelling of keys and other components (rarely in a plastic action Kawai admittedly) which can lead to this problem.

[genaa]

Hi Pianoguy,

The insurance company did finally agree to reimburse me for the piano but I still have it and it is actually playing extremely well - bar the sticking A0 which I should like to remedy if possible! I don't know whether it will develop any problems in future but given it has improved significantly since its return, and the felts and strings all seem in excellent condition, this now seems unlikely, particularly given the majority of the action parts being ABS as you say....

Do you think it more likely that lube of the bushing is required, rather than mechanical adjustment of letoff button or sticker?

[PianoGuy]

Do you think it more likely that lube of the bushing is required, rather than mechanical adjustment of letoff button or sticker?

Unlikely.

A tight bushing in the jack (fly) will result in poor or non repetition of the note rather than what you're describing, which sounds like the hammer isn't escaping correctly. Another possibility is that the check is wrongly ajdusted and is pushing the hammer to block on the string via the balance hammer. You could try easing the check towards you a touch.

PG

[genaa]

Hi PG,

I adjusted the letoff button marginally - good as new now