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Hi Terry,<br>
For a performance regulation, Top key quality key bedding is a
given not a choice.<br>
Japanese and Korean action rails will not stay stable at the
1/32"(let off) tolerance and handle the humidity swings, you can get
it up this tight for a performance but don't expect it to last. <br>
Remember that Fir or Spruce expands and contracts quite a bit
tangentially, so the rails will move quite a bit more than their maple
counter parts.<br>
<br>
Now I become bilingual, dip on most Asian pianos should be in the 10mm
ball park. Shot for about .020" after touch.<br>
<br>
To attain 1/32" let off and minimal drop, with 1/4" <i>ppp</i>
checking in the lower registers the tail geometry has to be very good,
and back check faces, parallel with the hammer rail.<br>
<br>
1. Tail should be at 90 degrees to the hammer shank, if not, and is
angled, the check has the tendency to push the hammer tail out of
check. If check and tail is at 90 degrees to the hammer rail,
the check is evenly trapping the hammer and shank against the centre
pin.<br>
<br>
2. Tail radius needs to be half the distance of the centre to tail
radius, ( about 5") <br>
So arc the tails at 2 1/2". Bill Spurlock's jig will do a good job.
Use new a 80 grit belt.<br>
Checkering should not be needed, nor is it desirable. Gina and I
differ on this a little, If you have a heavy set of hammers, I will 45
degree lightly checker the bass only with a coarse file, NOT a checkering
file. But we both agree that for a normal regulation checkering is not
needed.<br>
<br>
Terry, if bedding, tailing geometry, back check height, and rake are not
in order, you are not going to achieve the tight specs that you are
after.<br>
<br>
Hammer flange centre pinning starts to become critical at these
tolerences, so be on your guard in this area.<br>
<br>
PS. Gina and I have just finished writing, about a 5 page side bar to our
interactive reg articals just on checking and spring tension pitfalls. I
think it's chapter 7?<br>
<br>
Well I guess we are both long winded. <g><br>
<br>
Hope this helps<br>
<br>
<br>
<br>
<br>
<br>
A<br>
<br>
t 06:20 AM 26/05/00 -0400, you wrote:<br>
>Thanks for your thoughts Roger. The action frame is soft & hard
wood<br>
>composite - mostly soft with beech strips where the rail pins go. You
may<br>
>have a good point that the frame flexes in a different way on the
bench than<br>
>in the piano and that is changing checking. I fine tune let-off in
the<br>
>piano.<br>
><br>
>"> When you say it check's out of the piano, I'm assuming you
are using a<br>
>> regulation rack, if not, the hammer is travelling higher than
the string<br>
>line."<br>
><br>
>Yes, absolutely. That was a critical part of my question. With
let-off real<br>
>close and drop real small, aftertouch would have to be in the less
than<br>
>ten-thousandths of an inch range (I'm pretty quick w/ metric
conversions -<br>
>but I hope you are comfy w/ english units here!) to keep the hammer
from<br>
>blocking against the string upon completing the keystroke
through<br>
>aftertouch. Yes? When setting letoff & drop real tight, how do
you handle<br>
>aftertouch, i.e. how do you make it pleasing to the touch, yet keep
the<br>
>hammers from blocking against the strings?<br>
><br>
>Thanks billions for any thoughts<br>
><br>
>Terry Farrell<br>
>Piano Tuning & Service<br>
>Tampa, Florida<br>
>mfarrel2@tampabay.rr.com<br>
><br>
>----- Original Message -----<br>
>From: "Roger Jolly" <baldyam@sk.sympatico.ca><br>
>To: <pianotech@ptg.org><br>
>Sent: Friday, May 26, 2000 12:37 AM<br>
>Subject: Re: Aftertouch Question<br>
><br>
><br>
>> Hi Terry,<br>
>>
If the action frame is the soft wood type( not familiar with<br>
>> Boston's), there is Lot of flexibility in the frame. Bench reg
to piano<br>
>> rarely works. The key bedding is critical when you are
working at those<br>
>> tolerences, so the regulation has to be done in the piano.<br>
>> When you say it check's out of the piano, I'm assuming you are
using a<br>
>> regulation rack, if not, the hammer is travelling higher than
the string<br>
>line.<br>
>> Regards Roger<br>
>><br>
>><br>
>> At 10:02 PM 25/05/00 -0400, you wrote:<br>
>> >OK grand regulation techies, here you go! Two related
questions about<br>
>> >checking and aftertouch.<br>
>> ><br>
>> >I just did a full regulation on my Boston GP178 (5' 10"
grand). I set<br>
>blow<br>
>> >dist. @ 1-3/4", let-off as close as possible (about
1/32"), and drop (as<br>
>> >recommended by Steinway) as short as possible - about
1/16" or maybe a<br>
>tad<br>
>> >more - but less than 1/8". I have my checking up nice
and high - about<br>
>3/8"<br>
>> >over the treble & up, about 7/16" in tenor, and
about 1/2" in bass. Key<br>
>dip<br>
>> >is about 0.45".<br>
>> ><br>
>> >Out of the piano, all hammers check on even the softest blow
(I<br>
>roughed-up<br>
>> >the tails a tad). When I put the piano in the instrument, I
often get a<br>
>few<br>
>> >hammers that will not check on a light blow. And of course,
because I<br>
>have<br>
>> >the let-off so close and drop so little, the hammer rises up
and<br>
>> >blocks/bobbles on the string when pressing the key through
aftertouch.<br>
>> ><br>
>> >Question #1: Should ALL hammers ALWAYS go into check, even
on a very,<br>
>very<br>
>> >LIGHT BLOW?<br>
>> ><br>
>> >If answer to Question #1 is yes, then Question #2 is: Why do
all hammers<br>
>> >check out of the piano but not when action is in piano (keep
in mind, I<br>
>am<br>
>> >talking about very soft blows).<br>
>> ><br>
>> >If answer to Question #1 is no, then Question #2 is: If it
is normal for<br>
>> >hammers to occassionally not check on a very soft blow, when
let-off and<br>
>> >drop are real small, is it really feasable to make
aftertouch the<br>
>necessary<br>
>> >10 thousandths of an inch (or there abouts - perhaps even
less). Because<br>
>if<br>
>> >aftertouch is any greater, the hammer will simply rise up
into the string<br>
>> >and mute it in a very nasty manner. I like alot of
aftertouch - generally<br>
>in<br>
>> >the ballpark of 50 thousandths or so. I can't do that unless
I am sure<br>
>that<br>
>> >all hammers will check every time a key is struck - even
when struck VERY<br>
>> >LIGHTLY.<br>
>> ><br>
>> >Any good input for me?<br>
>> ><br>
>> >Terry Farrell<br>
>> >Piano Tuning & Service<br>
>> >Tampa, Florida<br>
>> >mfarrel2@tampabay.rr.com<br>
>> ><br>
>> Roger Jolly<br>
>> Saskatoon, Canada.<br>
>> 306-665-0213<br>
>> Fax 652-0505<br>
>><br>
> <br>
<div>Roger Jolly</div>
<div>Saskatoon, Canada.</div>
<div>306-665-0213</div>
Fax 652-0505
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