Action Ratio and Dip and Blow and Etc.

[Farrell]

Action time again for me again. I really struggle with action balancing issues. I must have action balancing Alzheimer's - every time I do it I feel like I am starting at square one again. Anyway, here goes:

Stanwood SWR (strike weight ratio) - I realize his method of determining this parameter is based on weights, but does it fundamentally differ from overall action ratio as determined by measuring lever lengths (ala. Overs or Gravange) or by direct measurement of key dip and corresponding hammer rise? Shouldn't these numbers be pretty close to the same?

I have difficulty measuring lengths and weights consistently. I have much more success using a few spacing jigs to measure action ratio directly - hammer rise divided by key dip - I can be very consistent with those measurement (and accurate, I think).

I'm working on an 1890s Knabe grand. Everything in the action is new except rails and keyframe (both of which have been rebuilt) and action brackets.

I know I should be posting a full analysis of a dozen sample keys, but I don't have all that yet - but I already have some questions about data from the first key measured - #16 in the bass.

Action Ratio:  5.67
FW: 36.25 (0.966 of Stanwood's maximum FWs)
KR: 5.1
DW: 50
UW: 27
BW: 38.5
F: 11.5
Blow: 48mm (1-7/8")
Dip: 9.85mm (0.39")

If you allow for a millimeter of letoff and add in maybe 0.030" aftertouch, you end up with a dip of about 9.1mm (0.36")

Most parameters above appear to be very good to me with perhaps the exception of the dip. Comments anyone?

9.1mm dip is shallow (or right at the shallow end of normal) for most pianos/pianists, yes? It seems to me this action has a very good action ratio, yet it has relatively shallow dip and a relatively large blow distance.

Any initial thoughts on how I have this thing set up before I go and make 88 of the same mistakes?

Thanks.

Terry Farrell
Farrell Piano

www.farrellpiano.com
terry at farrellpiano.com
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