My first pinblock

[Newton Hunt]

Pinblocks are not that mysterious, just tedious and detail
oriented.

First take every conceivable measurement you can.  String
heights, bearing all over, plate height, plate location from
stretcher and rim and block height.  

Think through this, beginning to end, write down the
procedure as you perceive it and add to that or rearrange it
as you think it through.  Have a plan, work the plan and
change it as you learn more.

Next drill two small (3-4/32") holes through the plate and
into the old pinblock.  One in the bass and one in the
treble.  These holes are your main orientation from this
point on.  Carefully measure, after plate removal, the
distance from the center of the holes to the rim and to the
stretcher and write them down on the keybed.

Carefully measure the thickness of the block material. 
Order the new block and have it thickness planed to you
dimensions by the supplier, unless you have a thickness
planer.

Precision cutting  will be needed here on.  Layout the
primary cut, the shape of the plate edge but remember, that
cut is at a three to five degree angle so you must account
for this plus the fitting removal of material.  Here you
need a band saw.  Tilt the table at the proper angle and
make a test cut and match it to the cut you need to make on
the block.  

You will need an air driven grinder/sander with 40 or 50
grit disks.  Home Depot or similar have these items.  Get
the disks made for this tool, don't cut your own.

Paint the plate (your choice of chalk, graphite, or other)
and lay the block into plate and MARK it's location.  Hit it
will a rubber mallet so you have marks and grind off the
marks until you get a nice fit, top to bottom left to right.

Clamp it in place and drill the holes through the plate and
into the new block.

Lay out the lines, and angles, on the new block from the
holes.  at the band saw cut the width and length of the
block and fit it into the piano.  Finish the fit with a
power planer or a good power sander.  Double, and triple
check everything.

At this point you need to decide if you are going to bore
the block in or out of the piano.  If in then just glue it
in and mount the plate.  If out then you need to put the
block onto the plate with three or four screws and center
punch each pin hole and the other screw holes.  Use a red or
blue pen to mark the screw holes so you know what to bore
for.  The angle o f the bore is determined by measuring the
angle to the plate where the string goes from 1/8" off the
plate to the riser or aliquot bar, between 2 and 5 degrees. 
What you want is the string coming off the pin perpendicular
to the pin when the bottom coil is 0.125".  Very simple and
uncomplicated.

You should use a cut off piece of pinblock and bore holes of
different sizes, F, G, 17/64" and pins from the set you will
use, mic those and write the sizes on the block.  Drive in
the pins and use a torque wrench to torque each pin and
write that on the block of wood.  Allow to lay around as
long as you can and check the torque as often as you can. 
Pick the bit size you like for the pin you like and go and
buy five of those bits, all from the same manufacturer, the
same lot, and change the bit every 50 holes or so.  Feed
speed is important; fast drilling makes a smaller hole and
slow feed makes a larger hole.  Feed speed is critical for
best feel.

Mic all the pins and arrange them in order, fat ones in the
bass and skinny ones in the treble.  Just don't touch the
threads with sweaty or greasy fingers.

The rest of the work you should be familiar with.  If not
scream here.
-- 
		Newton Hunt
		Highland Park, NJ
		mailto:nhunt@jagat.com