repetition/backcheck problem

[DMCKECH]

List,

Thanks to all for the responses to my inquiry. Below are my replies.

Newton wrote:
>1. Check touch weight, up and down and average the two to get balance
>weight.  If lower than 35 there is your problem.

Did not seem to be a problem when I completed the work. This is one worth 
revisiting though.

>2.  Check hammer and  wippen post pinning.

All is ok on this point.

>3.  Check the backcheck height.  On most S&S it is too high.

This point has been suspect. I am glad to hear someone else thinks this 
could be a problem too. What method would you choose to drive them in 
further?

>4.  Tail radius should be in the three to four inch range.

I make my radius 3 inches. 

>If these are in range then geometry, capstan location or knuckle
>location can be the cause.  Compare old shanks to new for knuckle size
>and location.

As stated in my post, geometry is suspect but where is still eluding me. 
Capstan location, knuckles and shanks are not the problem in my estimation.

Ed wrote:
>first thing that comes to mind is the question,  how far are the hammers
>checking from the strings?

I have experimented with different heights. No noticeable difference in the 
problem. I like to see about 1/2 inch. 

Jim wrote:

>Did you by any chance shorten the hammer boring distance in order to get
>a longer tail? This could cause all kinds of problems.

>Please understand, I'm not criticizing you. You may have just copied the
>problem that was there from before.

I understand Jim. I do the standard measurements of keybed to strings and 
keybed to shank flange pin, subtract, select an average etc. This piano 
exhibits the usual up and down string height one finds in Steinways. 
Nothing out of the ordinary, so I believe I am ok on this score. The longer 
tail length comes from choosing not to cut so much excess off. This refers 
back to the good articles (found in the Journal and CAUT Newsletter) 
written by Ken Sloane.

Charles wrote:

>I would be curious to hear which parts you chose for the action rebuilding.
>We have had similar problems to solve here in the past, and usually the
>cause was due to the relationships among the various parts.

For this piano I chose Renner shanks/flanges and wippens (with spring 
adjustment screw) and Isaac hammers. (Yes, I am aware of the argument 
between hornbeam and maple but I do not believe it is a factor here.) If 
there is a relationship problem I have not found it yet. I matched the 
knuckle distance and size with the old parts.

>Yet the problem seemed to gradually disappear on its own over time as the 
>action settled in--whether due to or in spite of my efforts I cannot say.

I have found this to be true on occasion as well. Wouldn't it be great if 
it just went away!

Well, here is the real kick in all this. I did a walkabout in the building 
and tried a number of different brands and found that I could make this 
happen on all! I must be getting good at it.  :-)  Some of the actions 
have had parts replaced and some are original. 

This begs the question about proper technique in playing. Not being a very 
good pianist, I need to consult about this. For a fast and short single 
note repetition, I was taught to use fingers one through four in quick 
succession not one finger repeating rapidly. With my limited ability, I was 
able to get good repetition on the pianos I tested by using the 
multi-finger technique. When you get a chance, please try this out. 
Obviously, I would feel better if someone discovered this as well!

I will tactfully broach this subject with my customer. As stated in my 
post, he is a very good pianist and I am sure he knows how to repeat a note 
in different ways. Perhaps it was our luck that one piece he was working on 
called for this type of one finger repetition. It must be stated that he is 
very satisfied with the action in all other aspects. Trills, touch and tone 
are no problem.

Don McKechnie
Ithaca College
dmckech@ithaca.edu