[pianotech] Best way to change touch on Yamaha Grand

[Denise Rachel]

Hi Techs,

First let me thank you folks for your detailed and passionate  
discussions.  Four or so weeks ago I wrote in about white keys not  
depressing adequately after having been recovered with no planing.   
Yes, you were all correct in your instant assessments.  Today it took  
me less than a minute to verify, and the best thing is that I didn't  
have to think about this problem while I was in my rush tuning mode.   
That was a relief.  Oddly, I had never encountered this situation  
before.

So, now after reading your posts about changing the ratio with cutting  
balance rail felts and about inserting little strips of wood, I'm  
wondering if there is anything more I should think about.  I am  
wondering if installing new thicker blacks to match the new thicker  
whites would solve my problem perfectly or perhaps lead to some  
unforeseen geometry problem.  If I hadn't read all of your recent  
posts, I'd assume that this is the way to go, but now you've all got  
me a bit spooked.

The key recoverer is not willing to remove the plastic, and has  
suggested a remedy that I know for certain would not work.  I hope you  
all say that installing raised blacks is the simple obvious solution.

Thanks

Denise




On Jan 6, 2010, at 8:49 PM, William Truitt wrote:

> Thanks Vladan, your explaination is clear now.
>
> Will
>
> -----Original Message-----
> From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org]  
> On Behalf
> Of V T
> Sent: Wednesday, January 06, 2010 7:11 PM
> To: pianotech at ptg.org
> Subject: [pianotech] Best way to change touch on Yamaha Grand
>
> 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"
>
>
>
>
>
>