wippen support springs

[Roger Jolly]

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At 05:56 PM 4/29/2005, you wrote:
>At 08:57 AM 4/29/2005, you wrote:
>>Thanks Roger and everyone else who responded. Would it not be easier to 
>>remove the springs and then accurately weight the keys.I will go back 
>>into my shop and play around with the springs and key weights.
>>
>
>Hi Jack,
>               I have a few comments that may or may not be helpful.
>
>#1 Friction:    It is extremely important to address ALL the friction 
>issues before attempting ANY weight off. Hammer shank flanges should be in 
>the 3-4 gram range. When holding the hammer shank and flange horizontal, 
>the flange should not fall under it's own weight, and should rise if the 
>shank is lightly tapped. (Easy to demonstrate but not so clear in 
>words)   You need some good friction in this area for consistent 
>regulation, and controlled ppp playing.
>Key bushings should be free, but exhibit no slop at the balance rail, and 
>slight side to side movement at the front rail.  Balance rail holes. 
>Lifting the keys 1/8" at the front, they should slide down slowly under 
>their own weight.  Using Teflon powder on the knuckles will also give you 
>a clearer picture of down weight.
>
>#2 Inertia:  Increasing the leading with out doing a complete analysis of 
>the action geometry can be risky. The action  set up may be designed to 
>need  some spring support to give adaquate up weight.  Too much lead can 
>lead to a sloggish action, so be carful.   I would need a complete down 
>weight/ up weight spread sheet to give some better advice.

Side by side with Identical pianos, one with assist springs supporting 10gm 
average, the other traditional weight off.  Feed back from Profs and 
performance majors, was over whelming in favor of the assist springs.
Both pianos was weight 54gms to 48gms, bass to treble.   I used 7 sample 
performers. One unanimous comment, more sensitive ppp control.   Voicing of 
both pianos, very close.  This was done to minimize the 
psychomatic  factor.  Perception in every thing when correlating  tone and 
touch.

To sum up.  Get all friction points within limits, fine regulation, even 
voicing, and a good tuning. before starting to evaluate.

Regards Roger


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