Renner repetition springs

[Phillip Ford]

David Love queried:
>The issue of how tight the balancier pinning should be has come up in the 
>past but not, to my recollection, been quantified.  The resistance should 
>be greater than the hammer flange and it should not exhibit totally free 
>movement.  An argument can be made that with tighter pinning in the 
>balancier you can increase the tension in the repetition spring and you 
>will get smoother and more predictable return without the hammer 
>jumping.  Some years ago I seem  to recall Rick Baldassin saying that he 
>routinely repinned the balancier on a new wippen with a pin one size 
>larger in order to improve repetition.  Does anyone out there actually 
>measure the resistance on the balancier and repin for a specific target?
>
>David Love

Dave Porritt responded:
>When I'm doing a real performance regulation I like to have the balancier 
>pinned to somewhere between 6 - 8 grams measured at the drop screw contact 
>point with spring disengaged.  I think it makes a lot of difference.
>
>dave

and Topperpiano added:
>I have always been pretty careful to have the rep lever pinned also 
>somewhere between 6-7 grams.  Pinning of course if a whole "nuther" 
>subject but consistency is the key.  If the rep is too fast then the 
>spring naturally gets regulated to a more weak position, and on Steinway 
>whippens affects the jack return ability.  If the spring is too weak the 
>jack is slow.  In my experience the only way to get better repetition is 
>to increase the friction of the rep pinning........TP

In the not too distant past, if I bought what I considered to be good 
quality parts (the subject line says Renner), I would just put them 
on.  These days, I generally check all pins, even on new parts.  I find 
that the pinning is inconsistent, even on what I would consider good 
quality parts.  I usually find that I'm only happy with the jack pinning, 
and due to inconsistency I will end up repinning some of those.  I find 
that the repetition lever centers and the flange centers seem too loose to 
me, as well as being inconsistent, so I usually end up repinning many, if 
not most, of those.  I also use the 6-8 gram number at the drop screw 
point.  I would also add, that while adding some friction to the rep lever 
center seems to improve repetition, you can go overboard.  A little 
increase in friction seems to help repetition, while a large increase 
doesn't seem to improve it further, and in my experience will negatively 
affect the checking on a soft blow.

Phil



Phillip Ford
Piano Service and Restoration
San Francisco, CA