Checks cause hammer bounce ?

[RicB]

Hi Jon

I suspected the hammer rail as well. Have this same kind of problem on a 
couple Yamaha C7's tho... completely different rail tho I know there are 
claims of hammer rail flex there as well.  Thing is an artificial 
stiffening of the rail does not change anything... i.e. using some tools 
in different ways to stiffen the thing as a check. Nor does applying 
pressure to the rail show any tendency for hammers to move.  So I have 
to wonder if the hammer rail is involved... and if so, why does the bass 
only get affected ?  Seems like at least the low tenor hammers are heavy 
enough if it had to do with hammer weight as well.

Got any good tests to confirm its the  hammer rail for me ?

Cheers
RicB


     >...the neighboring hammers started to bounce...

    Sounds like Tubular Action Rail flex. Short of replacing the rails
    with study engineered material coupling the rails will reduce this
    interaction.
    -- 

    Regards,

    Jon Page