Lower front weight first?

[Richard Brekne]

Hi Bob.

Ok... looking closer at these numbers makes me lean more towards a 5.7 
ratio then a 5.5 to begin with. Most of your Ratio figures are truncated 
downwards to the first decimal point.  So some of these are a better 
seen as off a point higher.  Plus I know the D model normally works out 
closer to 5.7 then a 5.5.

So... I'd go with a number 9 curve...  Starts at 12.4 grams and ends at 5.8

see   http://www.stanwoodpiano.com/SW-HWstandards3.pdf

Then install the FW maximums Stanwood published along with the kit 
information.

If you WBW is correct at 9 grams, this should yield you very close to a 
38 gram balance weight.  Any inconsistancies that you can measure after 
installing the FW's and SW's are due to ratio problems for each 
individual key.  These can most often be farely effectivly  be delt with 
by checking and adjusting knuckle angle, regulation issues that can 
effect the ratio, and even shimming under the key at the balance pin 
hole to push the key ratio around just a bit.Once you get BW smooth 
enough, then even out friction levels. They are reflected by uneven DW's 
once BW is evened.

In answer to you two questions below...

--- Yes  ... BW should stay fairly even over the whole keyboard... but 
may dip very slightly in the high treble... not unusual.
--- Yes  a number 9 curve will over nice tonal projection.  Perhaps in a 
very very large concert hall you might want to go up a bit.  But heavier 
hammers have a cost and you need to be ready to pay that.  My personal 
preference for a top end limit is a number 10 curve.  Opinions vary on 
this subject... but I see no point in getting heavier.

Hope this helps

Cheers
RicB



Bob Hull wrote:

>Hi Richard,
>
>Thanks for your reply.
>
>you wrote:  Stanwood suggests given SW curves for
>  
>
>>each Ratio and BW... 
>>tho you dont see that on most of the Smart Charts
>>published.
>>
>>If you give us some more specifics, perhaps we can
>>offer better advice.
>>    
>>
>
>Where are these sw curves suggested in correlation to
>particular ratios and BWs ?  You referred to a number
>10 curve.  I'll give some more details here about this
>action.  This is with the new hammers.
>
>N     SW    D    U    BW    FrontW     R     WBWAvg.
>___________________________________________________
>1    12.1  56   27   41.5    37.5     5.7     9
>2    11.6  56   27   41.5    32.9     5.6     9
>9    11.5  50   23   36.5    39.0     5.78    etc.
>10   11.7  53   28   40.5    32.6     5.4  
>16   11.4  48   20   34      40.8     5.7
>17   11.1  48   21   34.5    37.1     5.6
>28   10.8  48   25   36.5    32.1     5.5
>29   10.4  44   19   31.5    35.2     5.5
>40    9.7                    31.6
>*(40  10.8 48   26   37      31.6     5.5)
>41    9.6  40   17   28.5    33.1     5.4
>52    9.5  44   22   33      29.2     5.6
>53    9.3  46   21   33.5    27.2     5.5
>64    8.3  46   27   36.5    20.3     5.7
>65    8.2  44   26   35      19.3     5.5
>87    6.6  49   29   39       6.8     5.5
>88    6.4  50   34   42       3.5     5.7
>
>(*C40 had 1.1 g temporarily added to the hammer)
>
>Do I understand that BW should be fairly constant
>across the keyboard while SW, Frontweight and
>downweight are going to smoothly decrease?  Although,
>downweight may just decrease from 52 to 48. 
>
>Also, for good tonal projection is a sw of 12 enough?
>
>I hope this info will help you advise me if you don't
>mind.  Thank you.
>
>Bob
>
>
>  
>