I've just got myself a very old Kaps concert grand piano (1920 I think, but can't find the serial number), and I want to have a bash at fixing up the action myself if I can. I've already tuned it ok, but the action feels pretty bad. Some of the keys are stiff, others rattle, etc.
The first thing I wanted to try to do was to align the hammers, but all searches on the net recommend adjusting the Capstan screw, which as far as I can tell this piano does not have, so I'm stumped before I can even begin.
Here's a picture of the action: And some of the hammers: And here's the bit where the keys kit the wippen - I (a super novice) can't see any Capstan screw: (continued below)
And some more close ups thay may be of interest: Here's some hammers when some keys are pressed: And a side view with the hammers removed: I'd like to get the action reasonably good if possible. I'm working (with help from the missus) on fixing some of the felt inside some of the rattley keys at the moment, but would like to get those hammers aligned asap.
I know the best thing would be to call someone, and I did, but the only good one I know of in the country where we are at the moment, Uruguay, is on holidays until March, and I've no idea how good he really is, so any help would be greatly appreciated.
Cheers and thanks for reading,
I've started aligning the hammers today after sanding them this morning. Here are some at rest: The problem is when pressed down slowly they look like this: And when pressed down fully they appear like this: There appear to be three main things I need to adjust - the rocker screws, the letoff adjusting screw and the drop screw (at least that's what I think they are): I'm making some progress by trial and error, but I'm not really sure what I'm doing or why, or what the relationship between them is exactly - e.g. the drop screw only seems to have an effect at certain positions of the other two, and I'm not sure completely what the letoff adjusting screw is doing, and how it affects the half way position or fully down position or both.
Some info would save me hours/days of time I'm sure.
What part/parts are you referring to:
1) Breaking off the hammer heads, shortening the shanks, and re-gluing them
2) Adjusting the tension of the repartition spring
3) Reading "Complete Grand Regulation" by Roger Jolly
4) Reading "Piano servicing..." by Arthur A. Reblitz
5) Reading Kawai's Grand Piano Regulation manual
6) Something else I missed?
I'm not keen on number 1, that's for sure, and Reblitz's book is a bit heavy.
I set set-/let-off by the blocking method and then set drop by comparing each key with its neighbours. These became quite fine adjustments. Aftertouch was the final thing. I had to go round the loop more than once to achieve a reasonable result. What I learnt is that you should start with key levelling and key dip. I postponed some of that as the keys will need rebushing in the near future and, as a result, the hammer line is not quite what it should be.
The Kawai manual is great for a novice - Mr. Jolly's may be too, but it badly needs pictures, its hard to understand the prose when you are not familiar with the process.
Technicians spend ages learning to regulate grand pianos so a little bit of homework understanding how things work is warranted!
Google for "Foote aftertouch" or "Foote let-off".
The hammers are aligned, but if I place them hovering just over the rests this result in a distance from the string of about 5.6 cm. If the hammers at a distance of the recommended 4.6 cm from the strings then they will hover about 1 cm over the rests. Maybe this piano was designed to have the hammers 5.6 cm from the strings?
Here are pictures of the hammers - I lowered one of the hammers to be just hovering over the rests so you can see the problem - the others are at 4.6mm from the strings:
Thanks for all the help.
I managed to do some proper regulation and boy was I chuffed . I did the middle and treble strings and tried them out and things feel a lot better now than they did, far from perfect, but defo. getting there.
I'll leave the hammers hanging in the air for now and see how it goes, I can always change things around later on.
Thanks for the help!