REPETITION

[Avery Todd]

Hi  Rogerio,

   Sounds like you've pretty much covered most everything. How about the
backckeck adjustment? You say the friction is very good but you mention
it in relation to the knuckles. How about the pinning of the hammer shank
flanges, wippen flanges and jacks? Is the repetition spring groove gummed
up with graphite or anything else?
   Just some thoughts. Below is a list of grand regulation measurements
from an OLD handout I got at a convention many years ago (probably the
1970's). You don't say how old the piano is but I assume the measurements
would be about the same. I don't have anything newer.
   Let us know when you find the problem. Hope this helps.

Avery

>     I am with a great problem with a YAMAHA grand model G2 and I need
>help. All the measures that I did on it I think that they are very good:
>hammer weight, letoff, drop off, the jacks are  correctly under the
>knuckles, key deep etc., etc. but the repetition is poor  ! The friction
>is very good ( I used powder micro  Teflon).The repetition springs are
>good. There are a problem : I haven't the Yamaha  measurements and I used
>the relation key deep-hammer travel 1:5. What can I do in order to
>increase the  repetition that is poor. Rogerio Cunha - IC Member of  the
>Guild.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Key Height (keybed to underside of key covering) - 64 mm (+1  -0.3)
Key Travel - 10 mm (+0.2  -0.3)
Hammer blow - 48 mm (+0  -2)
Let Off - 3 mm in bass graduating to 1.5 mm in treble
Drop - Let off plus 2 mm
Sharp height - 24 mm (+1.0  -1.0)
Backcheck - 16 mm in bass graduating to 14 mm in treble

Just in case someone else has messed it up, the action spread (wippen
flange center pin to hammer shank center pin) measurement is 112.5 mm.