speeding upright repetition, "bobbling" hammers

[Billbrpt@aol.com]

    Karen, Thank you for your question about "bobbling" hammers. The short
answer is "yes", this means the false double or repetitive striking when you
play a key.
    I have written that, in order to have the fastest and best verticle
action repetition, you need to have a minimum amount of aftertouch and close
checking.  This provides for the jack to not overly escape from the butt and
reset itself back under quickly, before the hammer comes back to rest.  Jack
Wyatt's demonstration showed that this is possible even with the key only
returning half way and the hammer standing above the rail.  A verticle action
does not have a repetition lever because it does not need one!
    However, it is a natural tendancy for lost motion to develop because of
compression in the keyframe felt, the wippen cushion and the butt cushion.
 If there is already a minimum of aftertouch, a little lost motion will
create a condition of zero or even negative aftertouch.  The jack then cannot
fully clear the butt and the butt bounces on the top of it.  I've always
called this a "bobbling" hammer.  But the fact that you were not sure of what
I meant demonstrates that we need to minimize our use of jargon and
colloquial terms if we are to be understood.
    There arealready and there will be many more for whom English is their
second language who will use and depend upon this forum.  We don't need to
confuse them unnecessarily.  If they are to translate what is written here
into their respective languages for those who do not read English, our
language must be clear and concise.  We have a new correspondant from France
yet today.  I know that the French speakers call this condition «les marteaux
qui dansent».  (Literally, "dancing hammers").  This illustrates the
difference of perception that different cultures have when they view the same
action.  Americans "bobble" and the French "dance"!
     Therefore, I'd like to propose that we find a drier, more technically
descriptive phrase for this.  Here is my offering:  "false, repetative
striking".  Anybody have any other suggestions?  I'm open.
     Bill Bremmer, RPT
     Madison, Wisconsin