[CAUT] tight balancier - defining bobble

[RicB]

Hi again Wim

One thing is for sure.  If your hammers are not even touching the check 
on medium to light blows... then the field is narrowed quite a bit. What 
happens when you just push the keys through aftertouch without enough 
force to let the hammers actually hit the string ?  I dont mean like an 
aftertouch check. Use as much force as you can without letting the 
hammers make contact with the strings.  One test I ran into for 
rep-spring strength a while back went along these lines.  The rep-spring 
should be just tight enough so as to prevent the hammers from checking 
with this kind of test... but no stronger. You should see the hammers 
dipping say about 8-10 mm before springing back up to drop position.  
They should dip more then drop but less then check.

If you arent getting any of this kind of action then the rep-spring is 
too tight for whatever other conditions you have. Tight hammer centers 
will slow things down for example so a certain combination of these / 
tight balancier pins and strong rep springs could cause your trouble.  
Even if each of the individual parameters seem ok when checked 
by-themselves.  Point is... if the tails are not even hitting the 
checks.. then it cant be really much of anything else.  At least not 
unless something else is ridiculously out of wack. 

What else could cause the hammers to hang up so much that hammers wont 
even touch the checks ?... Hmmm... I suppose a lot of rather strange 
stuff could get into the picture... but I cant think of anything 
reasonable off hand.  Perhaps a very strong jack spring with minimal 
knuckle clearance could contribute.. ? I dunno..  what kind of strange 
tail arc and check angle could cause what you describe below ?

In any case seems to me you want to make sure whether the tails are 
actually making contact with the checks or not at this point. Maybe mark 
a few of the worst offenders with a bit of chalk on their tails and see 
if it rubs off on the checks ?

You really got an interesting thread rolling in any case there Wim.

Cheers
RicB


     > Hi Wim
     >
     > Are they actually bouncing off the checks ?  Or are they simply
     > hitting
     > the rep lever and getting sprung back up before they even touch the
     > check ?
     >
     > Cheers
     > RicB

    It's hard to tell. I beleive they don't even make contact with the
    check, but I've had notes that even on a medium hard blow, much less a
    hard blow, where the hammer doesn't check. It acts like it is not even
    touching the check, but it goes down far enough where the it should be
    hitting the check. But if I move the check forward, the tail hits it
    on the way up.

    Wim