[CAUT] Moving wippen rail

[Keith Roberts]

Most of the wippen rail adjustments will be made because of incorrect
installation or loose screws and shims that fall out. I am speaking from
past experience, last fridays to be exact. Mr Erwin was up at a very early
hour and was experimenting with the wippen rail of the action I was working
on. He pulled it 1mm out and said he thought the action felt better. Then he
put it back, or so he thought. I thought I had about 4 hours of regulation
but when I got there the hammers were blocking in one section. I was an hour
into the regultion when I noticed two of the rail screws were loose and the
end one was tightened up 1/2 mm away from the bracket. Then Dale got back to
the shop. well since it was half way there we moved the rail. The reasons;
the jack lined up with the core better The original action spread was 113
1/2mm as set by one of the brackets and the others were shimmed. The new
knuckle had moved out 1/2 mm  to 15 1/2mm and the jack leaned slightly back.
This causes an extra lift from the jack as the toe rotates the jack through
let off. The jack now lines up with the center core of the knuckle. What I
found was the rail was warped and the action ratio went from 112 to 114. 112
in the bass where all the lead was. When done the jack was lined up in the
rep window nicely and aftertouch which was little had a good feel. The
problem was the pad for the drop screw needs to be longer. The let off
buttons/jack toe lined up better.

Keith


On 10/28/07, Richard Brekne <ricb at pianostemmer.no> wrote:
>
> An interesting thought which Iwill have to ponder a bit.  I think
> Stanwood is busy looking at various reasons why different ratio
> perspectives can result in inconsistent ratios.. ie you can change the
> apparent SW ratio without necessarily changing correspondingly the
> distance ratio... or you can... depending on what you did.
>
> Thanks for the thought Keith
>
> Cheers
> RicB
>
>
>    I think the issue here is the discrepencies between the weight
>    change and
>    lack of change of dip and blow. There seems to be a denial that
>    there is any
>    change because the dip and blow ratio is the same. What will change
>    is the
>    aftertouch.
>
>    Keith
>
>
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