I've recently become the owner of a 1974 Kawai model 600 grand. The strings have been replaced, new pin block and tuning pins. The hammers look to be in good shape, without too much wear on the felts. Hammer knuckles show some very minor wear, mostly discolouration from the jack.
I have a basic understanding of the parts and action of the piano, and have been tinkering with it carefully over the last few days. I suppose what I'm lacking the most are the "rules of thumb" for the correction positions and alignments of the action at rest, and at different stages of the hammer strike.
Maybe I'll start off with a few very basic questions:
1. I read somewhere that the wippen should be such that the hammer head does not rest on the felt, and is suspended slightly above it in the stationary position. Is there a general rule for how much above the felt hammer rest it should be?
2. Where the top of the repetition lever butts up to the underside of the hammer joint (on my Kawai, the top of the repetition lever has a small pad that pushes up against the screw head at the hammer joint), should this be at the same height on all pianos. I've discovered that there are quite a few things that affect the total height extension of the wippen assembly, but I'll keep this question generic for now.
3. Similarly, I've also read that in the stationary position, the jack should be just ever-so slightly below the edges of the repetition lever at the opening. Should I use the jack regulating screw to position the jack directly square below the hammer knuckle? If the hammer knuckles are not perfectly aligned key-to-key, should the jack be adjusted to achieve the above?
4. Should the position of the let-off button be aligned for all keys? IE. should I level all the let-off buttons so that they're at the same height off the base of the action? Or do the specific adjustments to independent wippens demand that the let-off button be different in order to accommodate?
5. The height of the hammer rest, from what I can infer, determines to a certain extent the volume of the piano. My Kawai is currently quite loud, which is probably in part due to the empty room that it's located in (at the moment devoid of furniture and area rugs). I'm thinking of raising the hammer rest, but I don't want to compromise the key dip. Is there a way to adjust this without making the key dip too shallow?
6. Could someone describe the optimal position of the hammer and wippen when the key is slowly depressed all the way? Where the jack slightly kicks out from underneath the hammer knuckle and does a little wobble? I'm not quite sure how to describe it, but I'm sure you all know what I'm referring to. This "action" isn't consistent across all the keys, so I'd like to make them all consistent, but need to know what it's supposed to be like.
7. Similar to point 2, should the capstans all be at the same height as well? Or do these sometimes need to be different to accommodate the rest of the action?
Thanks in advance for any help! I apologize if I'm asking very basic and obvious questions. And Happy Holidays and Happy New Year to all!