Knuckle question

[justpianos at our.net.au]

Ok, since we have the attention of people working on this area of the
piano, here's one out of left field......
Has anybody thought to use grand rollers (hammer knuckles) on upright
actions, at the hammer butt. I'm just thinking that since they are already
available as a spare part they could be readily replaced as a "wear" item.
Naturally some modification would be required, but even manufacturers
could re-design this area.
Any thoughts? or just another stupid ramble....
Bruce Browning - The Piano Tuner.




> I am generally familiar with the term "high solids", but am not familiar
> with it being used to describe an adhesive (forgive me, I may simply be
> ignorant about that). Are you using the term as it might imply good
> gap-filling properties?
>
> If you shim the gap properly - and you really want to do that to place and
> orient the knuckle consistently - you will have a snug-fitting assembly,
> and thus any good wood glue will work fine - hide glue, Titebond, etc.
>
> Terry Farrell
>   ----- Original Message -----
>   From: Larry Trischetta
>   To: Pianotech List
>   Sent: Sunday, December 03, 2006 5:11 PM
>   Subject: Re: Knuckle question
>
>
>         Ed, and all who replied... Thanks for your valued advise. With all
> the input on this , I think I will use these knuckles and shim the
> gap, make sure the knuckle is perpendicular and all are uniform
> distance from the center pin and use high solid glue... Which
> raises the question; are hide glue and wood glue high solid glues?
>         Thanks,
>         Larry Trischetta
>
>         -------Original Message-------
>
>         From: A440A at aol.com
>         Date: 12/3/2006 8:03:50 AM
>         To: pianotech at ptg.org
>         Subject: Re: Knuckle question
>
>         << knuckles to install and the wood core is slightly
>
>         narrower than the slot (it reaches the bottom). Is it acceptable
> to install
>
>         and let the glue fill in the gap or should I shim it with paper or
> anything
>
>         else? Or is it un >>
>
>         The integrity of the shank assembly is critical.  Upon impact, the
> transient
>         forces will make a rattle out of virtually anything that is not
> tight. A good,
>         high solids glue should be ample for this, but it is really
> important that
>         the cores are exactly perpendicular to the shank and that you have
> a consistant
>         distance the center pin.  Otherwise, the resulting erratic
> geometry will
>         interject a variable into your regulation.
>         Regards,
>
>         Ed Foote RPT
>         http://www.uk-piano.org/edfoote/index.html
>         www.uk-piano.org/edfoote/well_tempered_piano.html
>
>
>
>