Renner "Turbo Wippens"

[Avery Todd]

David,

>If anyones in Houston this week? I'll be teaching a workshop:

   Just a quick, public thank you to you and Bob for a great class.
Warning: as I get more into it, you'll be hearing more from me with
questions. :-)

Avery

>     "Changing from one Up/Down Weight to another Up/Down Weight"
>
>
>Here is an excerpt from my handout.  We are all going to work the weight
>and friction on action models to change up/down to our desire:
>
>Three Steps:
>
>  I. Measure old Up/Down Weight, then calculate old Balance Weight and
>Friction Weight.
>     Pick a New Up/Down Weight, then calculate new Balance Weight and new
>Friction Weight
>
>II. Change the old Balance Weight to the new Balance Weight by adding or
>subtracting keyleads,
>     or by increasing or decreasing support spring tension.
>
>III. Change the old Friction Weight to the new Friction Weight by adding or
>subtracting friction in the
>      hammer flanges, wippen flanges, or key bushings.
>
>
>When talking about key balancing it is always preferable to talk BW because
>it separates out friction as a separate issue.  Sorry to get carried away
>here but this is an area that most of us can't deal with.  I hope to change
>that.  It's not rocket science, it's seesaw science!
>
>On the subject of Turbo wips:  One mistake that makers make is asking too
>much of a wippen support spring.
>The highest BW Balance to for use with support spring is 54 grams.
>Attaching the spring and achieving a final BW of 35 means the spring is
>working 19 grams off the BW.  The spring can be adjusted to as low as
>30gram BW for a very light touch, in which case it would be working 24
>grams.  This is our red line.
>
>We almost always use wippen support springs in all our action work.  I
>think they are great and they are an underutilized resource in piano
>making.  Piano makers just don't know how to use them the right way.
>An exception is the Hamburg Steinways of the 1920's who set spring to
>support the weight of the wippen on the bench and then balanced the keys
>using Up/Down.  Unfortunately there are piano makers out there, some very
>good ones, who ask as much as 40 grams or even 50 grams of the support spring.
>
>Ed, I agree that hammer weight can be a big problem.  So can overall action
>ratio and I feel that this an even greater culprit contributing to heavy
>actions.  In Steinway the big culprit is Key Ratios: they vary all over the
>Map!  yet this is hardly ever mentioned in discussion of trouble shooting
>heavy action.
>
>David C. Stanwood


___________________________
Avery Todd, RPT
Moores School of Music
University of Houston
Houston, TX 77204-4893
713-743-3226
atodd@uh.edu
http://www.music.uh.edu/