[CAUT] Steinway Style II questions

[RicB]

Hi Del

It would seem to me that raising tension or not on an older instrument 
has a natural structual limit of safety.  As long as you hold yourself 
safely within these boundries I would think one should feel free to do 
what one wants.

I am in the middle of an old instrument rebuilding at this time also. 
The instrument shows absolutely no sign of pinblock stress from 
overloading. No roll, or flexing of the area we'd usually call the 
stretcher. Nor do I find any real sign of structural strain in the rim 
and bracing. This thing had a total of just over 13000 kilos tension if 
modern string specs are used to figure tension. Roughly 29000 lbs. I'm 
probably going to increase that slightly to about 14000 kilos and most 
of the increase will be coming at the top of the scale.  The present top 
note #85 is at 48 mm long and it will probably end up around 50.5-51.  
Most of the top octave will increase slightly, and a few scattered notes 
to even out some humps here and there.

This is also getting a new soundboard and design.  The basic design is 
the same, but I've introduced some crown into the system using a 3 ply 
laminate setup in which crown was establised as part of the lamination 
process.  Otherwise.... the thing remains very close to the origional. 

I'm doing a bit of experimenting with ideas here to be sure... but 
essentially I'm hoping to give it a slightly more modern treble that 
gradually moves towards the original bass sound (which I have always 
liked).  The middle ply is thinned so as to take care of the original 
thinning of the soundboard as a whole. This also very gradually lessens 
the crown and crown strength I've introduced into the treble. With this 
I hope to be able to also introduce a bit of downbearing in the upper 
regions of the scale. More then likely the thing was pretty much strung 
without any downbearing at all. The original rib orientation would offer 
little support thus.  So a tad more tension... a bit more downbearing 
coupled with a bit more stiffness and strength from a panel that shows a 
non-linear spring rate...
 
Well... we'll see how it turns out.

Cheers
RicB


    I'm remanufacturing one of the early Type I (85-note, 8' 5") grands
    right now.

    There was no sign of stretcher/pinblock structural failure. In this
    case the
    customer and I opted to install a pair of pinblock inserts rather
    than remove
    the whole assembly and build up a complete new pinblock assembly.
    I'm still
    debating whether or not to install some type of gap-spacer to help
    carry the
    load. Once I get the major action parts installed and back in the
    case I'll see
    how much room is available and decide at that time.
     
    This instrument is getting a complete redesign--new soundboard & rib
    design, new
    bridges, new scale, new action, etc.--and, based on previous work on
    these
    instruments, I'm confident the results will be worthwhile. A caution
    is in order
    here: These pianos originally had relatively low-tensioned string
    scales and
    they should stay that way. I'm actually removing some tension from
    the scale of
    the piano I'm currently doing. The piano now has a new tenor/treble
    bridge and a
    log scale. As a result a significant hump in the middle of the tenor
    section has
    been smoothed out.

    No attempt should be made to make these pianos into modern powerhouse
    instruments. Properly redesigned and rebuild they are wonderful
    pianofortes.
    They cannot be made into fortes.
     
    Del