[pianotech] Square Grand Jack Springs and Cords

[Terry Farrell]

What is the proper tension setting on the spring - i.e. should the jack be parallel with the base with no slack in the string, or should there be some slack - and if so, how much?

Currently, most of the jacks on this piano will raise about 20 degrees or so from horizontal before the spring is engaged.

Thanks for your input Joe.

Terry Farrell

On May 29, 2012, at 9:46 PM, Joseph Garrett wrote:

> Terry said:
> "Is there a source for square grand jack springs? I don't have any broken
> ones on this 1867 S&S square that I am working one, but seems to me that as
> long as I'm replacing the cords, I might as well replace the springs. Seems
> I recall running across some broken ones years ago on other squares. Very
> thin metal springs - certainly 147 years is enough for them to have
> deteriorated a bit.
> 
> Yes? No?
> 
> Source?
> 
> Get out the spring-making tool?"
> 
> Terry ,
> Do the cords and leave the springs alone. There is little stress on them,
> for the most part. However when you have a broken one, it's time to
> replace...JUST the broken one, imo. I have some spring stock that is a
> close facimile of the originals. It is not for sale, as the original
> company that made it, although still in business, does not make it anymore.
> They would make some if I wanted to commit to about 5 miles of the stuff!
> It is hard to find, if at all, so go with the: If it ain't busted, don't
> fix it" Thang.<G> As for getting out the spring-making tool, Rotsa Ruck
> Dude! BTW, there are a few different configurations of those jack springs
> set-ups.. just so's ya know. The type that does not have the cords, is most
> prone to break and is the most difficult to fix!<G>
> Regards,
> Joe
> 
> 
> 
> Joe Garrett, R.P.T.
> Captain of the Tool Police
> Squares R I
>