Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Hammer height adjustment in grand

The proper distance of the hammers from the strings, if I remember right, is about 1 3/4 inches. The hammers are not supposed to actually rest on the hammer rests, ironically enough, but hover a little above them.

The action in my grand was restored about two years ago and was regulated at that time. When I got the piano a year and a half ago it had hardly been played and the hammer-string distance (checked by a technician) was OK.

Now, though, most of the hammers are resting on the hammer rests. The ones that are still 'hovering' are in the bass for the most part. From this I conclude that most of the hammers are now too far from the strings. I'm sure this happened because all the felt and leather in the action was brand new when I got the piano, and now it has all settled and compacted a little bit.

My question is, is it a good idea to raise the hammers simply by adjusting the capstan screw? Or more precisely, is a capstan screw adjustment better than nothing? (Since I don't have the budget for a professional regulation). Finally, if I try to go beyond adjusting just the capstan screw (here I would open the Reblitz book), which adjustments would I likely need to focus my attention on?

hello,

first check the tightening of the action screw, stack and flanges.

Then turn the capstan to restitute a hammer line.

To find the correct height check for aftertouch (if the key dip is good, checked with a key dip gauge or a little ruler) ther may be enough aftertouch if the hammer rise 0.5 mm after drop when the key is touching the punching.

4 mm between hammer shank and the cushion, at rest.

Many thanks. That is very helpful.

Wouldn't key dip probably still be OK, since the refurb is still quite new? The front rail punchings were all replaced professionally.

If the balance punching have been changed they take some time to settle, we hammer tem, iron tem, but the key level is not stable immediately.

The front punching also compress, we dont have those automats to settle the new parts.


Try to keep aftertouch consistent , testing ech note with 2 fingers together for more tactile feedback, align the hammer line to a straight edge placed in front of your eyes on the action. you decide how much aftertouch you like, if you raise the hammer too much the jack can crush in the lever cushion, so verify that a full key dip it still can be moved slightly. stay with a normal hammer stroke just raising a tad the shanks above the cushion, it will be more secure. The tone will tell you...

you can cheat a little on hammer line if a note have more or less dip, but it is not the best solution, which is to regulate a very even key dip.
not enough aftertouch and the key is noisy, the tone occurs after the key noise. Too much and the hammer rebound befor ethe key bottoms (some liike that kind of feeling with less percussion)

To me all this is clear, but I wonder what is undestood by the pianist in the end . Often partly it is OK but partly the concept is a little off..

I understand everything you're saying, partly because I've seen a youtube video using a straight edge to adjust the hammer line.

There is no aftertouch on many of the notes I have not adjusted, but the ones where I have adjusted the capstan screw height have a tiny aftertouch, as you say, about .5mm.