Chickering Quarter Grand Pinblock - another way.

[Will Truitt]

Hi Nick:

 

I’ve done a number of Chickering pinblocks over the years, both the two
piece and the four piece double level ones.  I’ve tried it a variety of
ways, and Kendall’s method seems to be the least slow (notice I didn’t say
fastest – these blocks are real time eaters no matter how you do it and I
hope you charge accordingly).

 

The only things I would add to Kendall’s comments are to make sure that you
start by having the top piece be too thick by a reasonable margin.  I fit
the block both to the underside of the plate flange as well as to the face
flange by removing high spot marks in the usual fashion.  Then I joint
material off the bottom of the top piece until it is the correct thickness,
checking with a straight edge over the section on the bottom of the plate.
Also, it is my practice to slightly enlarge the tuning pin holes in the
plate and install the modern narrower diameter tuning pin bushings.  Adds
about half an hour and the piano will tune better.  When I am ready to glue
the two pieces together, I have drilled holes for bridge pins on the drill
press in the four corners and tap in bridge pins to use as indexes.  With
the top piece sitting in the plate, I press the bottom piece against it and
get my four marks.  After drilling those holes in the top piece, I am ready
to glue the two together, which I do outside the piano.  

 

Because the top of the top piece is angled down, I think the multi-lams are
the better choice (other rebuilders mileage may vary).

 

Boy Nick, if you have gotten this far into your rebuilding career before
running into one of these puppies, you have led a sheltered life!  Here in
the Northeast, it’s usually not too long before any rebuilder has to cut his
teeth on one of these.  Chickerings for me have always been a bit of a
perverse pleasure – they really can have their charms amidst all those flaws
and overly complicated design.  The conventional wisdom here is that no two
Chickerings are alike.  That’s not quite true, but they sure changed things
a lot as they went along.  Some of those quarter grands are so narrow that
the cheek blocks are about as wide as a sliver of paper.  Always liked the
curves of the plate though.

 

Will Truitt

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Kendall Ross Bean
Sent: Sunday, July 20, 2008 4:25 AM
To: 'Pianotech List'
Subject: RE: Chickering Quarter Grand Pinblock - another way.

 

Nick~

 

There is another way of fitting the two step pinblock. I don't know if it is
easier or faster than the router table set up, (I haven't tried the router),
but this worked well for us. It involves different tools. (No router.) One
of the problems with a router setup is that the old pinblock sections
sometimes have shrunk away from the plate flange, so if you are using the
old pinblock as a pattern or template that way, you could still be off.
(Also the router method requires a lot of setup IMHO) The method I used
allowed me to individually fit each individual "step" to its respective
flange on the plate, just like you would a normal pinblock. If you only want
to get "close" to the flange profile and then make up the difference by
glassing, I guess that's possible too.

 

Consider the two step pinblock as two layers that can be "disassembled".
Measure the overall thickness of the old pinblock, and figure out how thick
each layer needs to be. You will be sawing the old pinblock apart, into two
layers (or two individual steps). (By the way, this works for all sorts of
other double step pinblocks as well. It's how we used to do Victorian
Steinways.) Each one of these old pinblock "layers" can be used as a pattern
to make the layers of the new pinblock, which can be individually fitted to
the plate flanges/recesses, and then glued together, using the plate itself,
and clamps, as a fixture. (Just as you would a normal pinblock, make each
layer slightly oversize so that it can be fitted to the flange.) Drill the
machine screw holes, after the assembly is glued together, in such a way
that the bevels on the flathead machine screws pull the block tightly
against the plate flange,  then mark the tuning pin holes with a machinist's
punch. Remove the glued up pinblock from the plate recess/flange and drill
it on a 7 degree tilting table on the drill press (or if you want, you can
drill it in the piano, if you have the set-up to do that).

 

If you have a bandsaw that has sufficient height (I have the Delta with the
height attachment, but you may not need it -  as I remember the Chickering
pinblock wasn't that deep/wide) you can easily saw the old pinblock apart
into the two layers. The bandsaw does make a kerf, so that's why you need to
know the thickness before you rip the old block apart. If you use a
relatively narrow blade on the bandsaw (say 3/16' or 1/4 " x 10 tpi) it will
tend to deflect backwards rather than curving to the side, making a
straighter cut than a wide blade. (A trick I learned from Mark Duginske's
Bandsaw Handbook). I use a ripping fence on the bandsaw that is angled to
compensate for the bias of the blade (have to change it for every blade) but
you can just eyeball it as well, or use one of those little resaw point jigs
to keep the pinblock vertical while you try and follow a pencil line or the
side of one of the "steps".

 

You'll need to make new pinblock layers that are the same thickness as the
ones you cut from the old pinblock, plus the kerf. It's easy to make these
from stock pinblock panels using a bandsaw to "resaw" them to proper
thickness, and then a planer or jointer to surface. You can try to duplicate
the original lamination thicknesses, using different types of pinblock
blanks, or you can just use something like Delignit.

 

Some pinblocks, we were able to separate the laminations into two layers
with a putty knife or chisel. They just sort of fell apart. Others are
better sawn.

 

I believe I used dowel centers to locate the machine screw holes in the new
pinblock. You can also try using the old pinblock as a drilling template,
but that's dicier.

 

I seem to remember on the last quarter grand I did there were basically two
pinblock sections, a bass (short), and a treble (long). But other
Chickerings we have done have different configurations. One larger grand had
four individual pinblock sections.

 

If you want, I took quite a few pictures of the operation I can e-mail you,
and give you more details with the actual sequence. It actually went quite
fast, from what I remember.

 

Sincerely~

 

Kendall Ross Bean

 

PianoFinders

www.pianofinders.com <http://www.pianofinders.com/> 

e-mail: kenbean at pianofinders.com

 

Connecting Pianos and People

 

  _____  

From: Nick Gravagne [mailto:gravagnegang at att.net] 
Sent: Saturday, July 19, 2008 5:23 PM
To: pianotech at ptg.org
Subject: Chickering Quarter Grand Pinblock

Hello All,

 

I have found myself knee-deep (and delightfully so) in an authentic
Chickering Quarter grand rebuild (belly job only).  

 

Questions: most of us know about the machine-screwed, two-step pinblock fit
to the two-step plate flange (ouch). I understand per my fellow tech and
friend, Les Conover of Albuquerque, how to fit the new block using a
straight ¾” router bit and a router table set up. Any other (aka simpler?)
ideas out there?

 

Also, I would like to replace the agraffes, but the original threaded studs
are slightly smaller in diameter than the standard size available today. Has
anyone re-bored and re-tapped the holes to accept a standard ¼” stud?  Or
might it be better to remove and recondition the existing agraffes?

 

Progress thus far: the crowned soundboard is made and fitted to the case;
the bridges are underway; and it is now time to begin thinking seriously
about the block.

 

Thanks for your consideration.

 

 

 

Nick Gravagne, RPT

 

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