lowering inertia without voiding warranty?

[William Monroe]

Bob,

Yes, remove one of the felt BR Punchings when you do this.  You shouldn't 
have a half felt punching and a full felt punching.  Key level will not go 
up.  If anything it might go down a very few thou.


David,

I thought this was an Estonia 190.  Do they have half-rounds at the balance 
rail, too?

William R. Monroe




> Mark,
>
> you misunderstood Bob.  What he intended to convey to you was the 
> technique you described below, of putting a little glue on the bottom of 
> the key, putting the key down on the punching, letting it harden, then 
> lifting the key out and cutting off part of the punching... thereby 
> shifting the pivot point of the key...  to lower the ratio and lighten cut 
> off the front part of the punching as needed and vice versa.
>
> I know because to my knowledge I originated the technique and taught it to 
> Bob over a decade ago.  I've taught the technique to many many people 
> since then but I've never published anything written about it... maybe on 
> this list or maybe someone I taught it too mentioned it on this list...
>
> However if the piano is under warranty then it must have accelerated 
> action so the 1/2 punching technique won't work on this piano...
>
> I'll mention to Bob M. that he needs to be more concise when he describes 
> the method, especially in his classes...  thanks for the feedback...
>
> David S.
>
>>Bob at Pianotek was helpful. He suggest adding 1/2 punching to the key
>>at the balance rail. My punchings are scarlet (.055). Not having any, I
>>used several layers of maksing tape to get up to about .033, in the
>>shape of a regular puncing, cut in two, and stuck them on --facing the
>>right way-- at the balance pin hole of the key.
>>        This indeed did lighten the feel of the piano, but it caused it to 
>> be
>>sluggish. Plus it raised the key height 1/16 and the back end, nearly
>>3/8" (which makes since with the leverage as we calculated is above
>>that 6.2 to 1.
>>       The way I've done this (and I'm pretty sure that I learned this 
>> from
>>somebody else on this list) was to use the existing punchings. Apply a
>>very small amount of glue to the bottom of the key  just behind the
>>balance holes, and reinstall the keys. Once the glue has set remove
>>them and slice off the front half of the punching with a sharp blade.
>>Done this way it shouldn't affect the key height much at all -
>>certainly it won't raise it. My question would be is there really a
>>difference between this and moving capstans - from a warranty-voiding
>>perspective, that is. And if there is...should you really care?
>>
>>- Mark Dierauf
>>
>><snip>
>>>The AR, shows the inertia.   I'm (we) are looking at
>>>6.2. I would like it around 5.5, and lower the FW into the low to medium 
>>>range.
>>
>>>We've figured out that the key geometry is in trouble. But to move the 
>>>capstan or knuckle,
>>>will void the piano's warranty.
>><snip>
>
>
>