Rollers (Knuckles)

[harvey]

Hello Barrie,

In backwards order:

I understand rollers, but permit me knuckles instead, so I can maintain
consistency without trying to translate from English to English(!)
Similarly, I don't know the translation for "trade job", unless that's
subcontracted or dealer work, so will skip that.

I'll also discount the part about direction of nap. If the manufacturers
can't get it right, why should we be concerned? (just kidding -- at least
on everything after the comma).

Although the Dremel-type saw may work, and in spite of preferring power
methods, I think I'd prefer something like a miniature back saw. I would
tell you =why= I prefer this, but would rather not discuss it. These
miniature saws are available to fit an Xacto handle, and/or are available
self-contained (handle and blade) from many hobby shops. They are sometimes
used for cutting track on model railroads.

I'm not familiar with soaking with Meth, but it's beside the point. I've
never soaked off a knuckle with anything. There are still other methods for
extraction.

One method that the old-timers use: Secure each shank/knuckle combination
in a bench vise, with the (bottom of) the shank even with the jaws, and
whack the knuckle sideways (across the slot) with a hammer. Works like a
charm. Plus: (1) shank is reinforced, thus no damage; (2) flange is out of
the circuit, thus no center pin trauma; (3) can be mildly entertaining.
Minus: (1) must remove each shank/flange; (2) you'll be finding knuckles,
one at a time, for months afterwards.

The next method is to use a "portable" vise. Francis Mehaffey makes (or did
make) these and they were distributed through Pacific Piano Supply. The
vise is simply a modified  pair of slip-joint pliers (what you might call
gas pliers). Here I need a picture: The jagged, course teeth in the widest
portion, normally used for pipes or fittings <sic> is left intact. The
finer toothed portion at the front (where the jaws actually close against
each other, is ground smooth and flat, and also recessed. The very tips are
left in their original state, except... Rats, I can't draw this and
obviously can't write it either! All this grinding is to shape the jaws to
hold a knuckle securely, *and* to support the thinned slot portion of the
hammershank, *and* to eliminate (or minimize) trauma to the shank/flange
pinning. In other words, the entire shank and knuckle are "wrapped" with
the plier jaws, except for the area at the notch. The benefits: By raising
every other shank, another pair of pliers or nippers may be used to rock
the knuckle out of the slot. Inevitably one, or six, of the core wood won't
survive the extraction, regardless of what glue was used. That's where the
little saw comes in handy -- It's sharp enough to saw out the core, and
delicate enough to clean the slots of those that have some splinters
remaining.

If you don't like either method, just use some diagonals to shear the
knuckles off level with the shank, leaving the core wood in the slot. Plus:
(1) none. Minus: (1) everything (2) no control (3) no guarantee of
consistency -- or success.

Notice that the saw is the only constant in these methods.

You didn't mention this, and perhaps you have a source for good knuckles,
so it's not important. However, when quality knuckles were unavailable here
(at any price), I'd buy at least two sets, mic each of them, and separate
them into different stacks, according to size. The absolute loosers (too
skinny, not round, etc.) would get tossed, and those with marginal
acceptability became individual field replacements. I'd then orient the nap
on the chosen set and place the cores in a kerfed board. This is admittedly
an extra step, but actually saved time over picking up one knuckle at a
time, finding the (sometimes illusive) nap direction, then installing, and
so forth.

Sorry about the botched explanation on the plier!

Regards,
HarveyTheDopeyTechWhoThoughtMethWasForDrinkingNotSoaking (thanks Richard)

At 06:55 PM 8/21/98 +0100, you wrote:
>I have a set of Rollers which some dopey Tec  has glued the wooden tails
>in to the sockets, It looks like PVA glue.   If is had been animal glue
>it would not be so bad, I would soak them over knight in Meths and they
>would then come out ok. The last person who did the Rollers did not even
>take notice of the direction of the nap they are all over the place.
>
>My question is have anyone used a small circular saw or band saw to cut
>out the groves on the shanks.  I was thinking of the little Drimmel
>craft table saw. As my band saw is a bit vicious for this job.
>
>BTW it is a trade job so new shanks are out.


Jim Harvey, RPT
harvey@greenwood.net