[pianotech] Yamaha CFIIIS

[Hank Lea]

Paul,

I would check to see if the hammers are 90 degree to the strings. I had a
machinist make me a small square to sit on the strings and hang down between
the strings. I line up the center of the hammer to the square. You will need
to draw a line through the hammer to determine the center line of the
hammer.

A slight over-centering isn't that bad but will get worse as the hammers get
filed.  To determine the hammer bore, you need to measure the string height.
Then measure the height of the hammer shank center pin to the keybed.
 Subtract that number from the string height and you have the correct bore.
Some technician will add a 1/6th to that for wear.

I measure the first and last hammer in all sections, then measure the center
pin height on shanks #1 and #88.  I then figure the correct bore for each
section. I have found that some piano's have enough difference to make a
tapered bore. This will allow the hammer shanks to sit at the same height,
therefore making the dip and aftertouch even along the entire keyboard. I do
this on all piano's.

Hope this helps,

Hank
www.coloradopianoworks.com



On Mon, Mar 22, 2010 at 10:04 AM, Dempsey Jr., Paul E
<dempsey at marshall.edu>wrote:

> All,
>
> We have a Yamaha CFIIIS that was purchased in 2004. When it arrived,
> everyone, and I mean everyone (Students, faculty, and guests), forsook the
> 42 year old Steinway D that it shares the stage with in favor of the new,
> "shiny" piano.
>
> Slowly but surely they all came back to the Steinway. Reasons varied, but
> the common thread was that the Yamaha lacked the power of the S&S, and had
> no "personality" so the CFIII was orphaned  in favor of the D. A tech from
> Yamaha visited and spent two days with the piano but everyone still goes
> with the old piano.
>
> So, we are in spring break and I have some time to devote to the
> Yamaha-reshape hammers, reg and lube, mate strings and voice. You know the
> drill.
>
> I am noticing that the hammers are hung with a slight distal angle (about 3
> degrees)
>
> Is this normal for the CFIII? Also, looking at the string impressions in
> the strike point (they aren't too bad really), it appears that the hammers
> are very slightly over centering.
>
> Is the 3 degree bore angle correct? I guess I need to confirm the proper
> bore distance too. There is no $$$ for new hammers.
>
> Thoughts?
>
>
>
> Paul E. Dempsey, RPT
> Piano Technician Sr.
> Marshall University
> Huntington, WV
> 304-696-5418
> 304-617-1149
>
>


-- 
www.coloradopianoworks.com

Musician's Serenity Prayer:
God, grant me the serenity to start each day on a joyful note,
The courage to sing the song of my heart,
And the wisdom to trust you to always accompany me.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100322/50e0ac2c/attachment.htm>