[CAUT] hammer line

[Jon Page]

I weigh shanks and separate them into piles to the .1 g.
Then I measure the height of the knuckle, measuring
the shank too (the shank width variance is negligible)
but the knuckles are not always pressed in the same.
So I further break down each weight pile into three groups:
low, med, hi.  I try to keep the variance within .010" (.25mm)
and set aside ones out of the 'window'.

I weigh the bored/tapered heads and plot their weights on a chart.

According to the hammer weight, I'll select the appropriate weight shank
to achieve as smooth of a SW curve as possible bearing in mind knuckle
height groupings to place the med's more central and the low's and hi's at
the extremes, screwing the shanks to the rail as I go.

Grouping like-height knuckles leaves a more even let off button line and
one less variable with note to note wippen/shank vertical placement
(I know there's a better word for this).

By assigning a specific weight shank to a hammer weight less SW adjustment
is needed at the end of the process, ie; if the hi bass weighs 9.5 and the low
tenor weighs 9, using the same weight shanks will leave the .5 g difference.
But if you place a 1.7 g shank with the bass hammer and a 2g shank
with the tenor you will come out with 11.2 and 11, respectively.  Depending
on the availability of sizes, you can strive for the same weight or a 
.1g difference.

I then install the hammers and let dry, then remove them from the rail.
Next is to cut the shank protrusion off with a band saw and rough cut the arc.
Cut all tails to a even length ( I order longer moldings to accommodate a
tapered bore) and sand the tails to a 3" arc. This produces a nice 
finished edge.
Arcing removes about .3g.

Now comes the final weigh off. Usually only 12 to 18 need addressing.
I precut the hammer leads so I only need to look at the graph to install the
appropriate lead. If material needs to be removed. I'll first look at 
the front side
of the cove to remove a few tenths with a Forstner bit.  I order sets uncoved
as well; so as not to be hindered in the arcing process with a deep cove. The
cove removes so little weight, it is not worth the effort in the 
scheme of things.

FInally, easing the rear edges and bottom of the tail with a file. Reinstall.
-- 

Regards,

Jon Page