Upweight Maximums

[David Love]

25g of UW is nice if you can get it at the right balance weight.  With 15 g
of friction at the bottom of the piano then a 40 g BW will give you a nice
feel and the upweight will graduate up to, probably, 30+ at the top of the
scale.  Assuming 80-85% of  front weight maximums, that still allows for
adequate strike weights with some ratio tampering if you like slighlty
higher SW's or lower front weights.  Allowing the bass to go down to 23 g
UW is okay too as most of the piano will be 25 g and above.  It's a good
default setting, in my opinion.  I aim for  37-39 g BW under normal
circumstances, 40-42 g BW for a concert instrument.   I like to keep the
ratio at 5.6 or above.  

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Bill Ballard <yardbird@vermontel.net>
> To: Pianotech <pianotech@ptg.org>; <davidlovepianos@earthlink.net>
> Date: 4/6/2003 4:42:02 PM
> Subject: RE: Upweight Maximums
>
> At 4:06 PM -0700 4/6/03, David Love wrote:
> >I think that having adequate upweight is important and I would
> >choose a slightly higher balance weight in order to achieve adequate
> >upweight.  But it would not be my choice to set the action up as
described.
>
> UW needs to be adequate to satisfy two requirements: a safety margin 
> during summer humidity, and for fast repetition. As to the former, 
> I'd always heard that 20g was enough. As for the latter, I don't know 
> an actual quantity, because here, the velocity of the parts, and the 
> relationship between jack and balancier pinning, and the rep spring 
> strength are equally important players.
>
> I'm happy with 25g. I wouldn't need to go as high as 30. And I agree, 
> I may wander outside the infield in adjusting action ratios, but the 
> LHTR is one corner of the outfield I don't usually go.
>
> Of course, Ric was pretty sparse in his details of the actual piano 
> and pianist (and I gather, technician). I expect we'll hear from him 
> soon.
>
> Bill Ballard RPT
> NH Chapter, P.T.G.
>
> "You'll make more money selling my advice than following it"
>      ...........Steve Forbes, quoting his father, Malcome
> +++++++++++++++++++++