[pianotech] Best way to change touch on Yamaha Grand

[V T]

Hi Will,

I think, the original idea was to put a punching down (around the pin) and spot glue one half of it to the balance rail. Then, you cut some of the unglued end off. For example, if you are trying to reduce the ratio, you would, put a spot of glue on the side of the balance rail that is facing towards the hammers. When the glue dries, you cut some portion of the unglued side of the punching off. This makes the key pivot on the edge where you cut. It's a little more complicated than that, because the pivot point is constantly shifting, but in essence, you are removing any possibility for the key to pivot on the edge that you just removed. I hope I explained this well.

Nowadays, I think most people will glue a thin strip of wood along the entire row of pins. The distance between the edge of this strip and the balance rail pin determines how much you end up changing the ratio. It only takes a little to get a noticeable change. Then, you put your normal punchings over that. I don't have a photo handy, otherwise I would post it.

Vladan

============
"Vladen, could you explain a bit more completely
how you go about doing this?  I am having trouble visualizing your shim -
fulcrum in terms of material used and its co-existence with balance rail
punching and felts.  Thanks.

Will Truitt"