Dear Les:  I have been away and just found your post about your
repinning efforts.  I am sure others will respond but I am compelled
to respond now and hope I am not too late.

*Please Stop* before you completely destroy that cylinder!

Cylinder repinning is not something that should be attempted by an
amateur.  By drilling out the old pins, you are enlarging the holes
far beyond their proper and necessary size, which will cause serious
problems with interference with the comb teeth when the adjacent tune
tracks are playing.

I am one of a very few persons in the US who are set up to do antique
cylinder repinning in their own shops, that is, utilizing the proper,
specially-made wire, and the original, proven methods and techniques
for the job.

There are several music box restorers who advertise repinning service,
but many of them actually ship their customers' cylinders overseas,
which in my view, ads an extra degree of risk.

In any event, it is a complicated job, involving several tedious,
sequential steps, and if you don't follow them ALL to the letter,
you will render the cylinder more damaged than it was before, and make
subsequent repair far more difficult for a qualified repinner.

There are several books which explain the process in varying degrees of
detail.  Assuming you did not investigate any of these, based on your
approach, I will try to relate it to you as concisely as possible.

The cylinder is lined with a hardened mixture of crushed brick, fine
sand, pine rosin, and shellac. This very hard interior coating is
partly what makes individual repinning impractical.

Even if one can punch the broken pin through into the inside of the
cylinder, this usually will result in fracturing the cement filler all
around that area of the cylinder wall, and leaves the smashed fragments
loose in the cylinder to buzz and vibrate as the cylinder plays.

Also, this procedure can often leave a dented cylinder, and will
require the use of oversize wire to replace the punched out pin.  All
things considered, it is NOT a good idea.

As you have already learned, drilling out the old pins is nearly
impossible, due to the fact that the old pin is steel and the drill
tends to slip off into the softer brass, leaving a hole that is no
longer in the correct position.  This causes errors in timing, and even
interference with adjacent tune tracks.  Also, drill bits of the proper
size which are capable of drilling through tempered steel wire are very
expensive, and easily broken.

The correct procedure is as follows.

1)  Remove the comb or combs first!  Cardinal RULE!!!

2)  Let all spring power down.

3)  Carefully remove cylinder from bedplate.

4)  Drive out taper pin or remove s-shaped wire retainer from pinion
end of arbor.  With a female-centered small gear puller, gently pull
the pinion gear off arbor.  Then remove spring, and slide cylinder
completely off arbor shaft.

5)  With an accurate micrometer, measure existing pin height at several
places around periphery of cylinder and all along its full length.
Take great care to record these readings accurately.  Later on, these
will be used to determine how much of the new pins you will leave in
the grinding process.

6)  Next, both cylinder end-caps are removed.  The cylinder is
suspended vertically with a length of  heavy wire a few inches above
a suitable metal container to collect the melted cement filler.  I have
found a clean coffee can works very well.

Using a hand-held propane torch, on low flame, the cylinder walls
are heated uniformly, with the flame constantly moving up and down,
until the filler inside begins to melt and runs down into the container
provided.  This is tricky and somewhat risky.  Too much localized heat
may distort the cylinder, or may cause the cement to catch fire.
A ready fire extinguisher is a MUST!

7)  Now the remnants of cement which did not entirely melt out of the
cylinder must be removed with an appropriate solvent.  After it is all
clear, the cylinder should be thoroughly washed with a large bottle
brush and liquid soap.

8)  At this point, the metal dividers must be removed from the inside
of the cylinder.  They would be destroyed by the next step if left in
place.

9)  The cylinder is submerged vertically in a suitable sized Pyrex
graduated cylinder which contains an appropriate dilution of  research
grade sulfuric acid in distilled water.  The cylinder is supported in
the acid bath with a heavy copper wire, run through its center.  Copper
is used because it will not react with the acid immediately as would
steel wire.  The steel pins in the cylinder will begin to dissolve and
will be completely gone in 18 - 30 hours time.

The progress must be closely monitored.  Not enough time in the acid
will leave fragments of the pins in the holes, and too long in the acid
will allow the acid to begin attacking the brass surface.

10)  When the acid has done its job, the cylinder is removed and
allowed to soak in a neutralizing solution, then washed and dried.
Now it can be reassembled with the dividers returned to their exact
positions, and the end caps replaced, and remounted to the arbor.

11)  The cylinder assembly is then mounted on a suitable wooden fixture
to carry it as the pins are replaced.  Having determined the correct
diameter pin wire to use, the pins are replaced one by one, starting
from one end of the cylinder and working within groups of a few tune
track lines at a time.  One must have a source for the special wire to
be used, and must make up a few suitable hollow tipped tapered punches
for setting the pins in the cylinder.

12)  When all pins are replaced, the cement filler is again melted and
poured into the cylinder, which is then spun on the lathe above a low
flame source until all the cement is liquid.  Then the flame is removed
and the cylinder kept spinning for about 45 minutes or until cold to
the touch.  Now the cement filler should be a glassy smooth, uniform
coating inside the cylinder.

13)  The cylinder is mounted in the lathe, and with a proper fine grade
stone, the pins are slowly ground to their correct final length.  They
must be measured carefully throughout the process to insure they are
brought to the original length as previously measured, but no shorter.

14)  When all the pins have been ground to length, the cylinder may
be polished and reinstalled in the mechanism.  At this point, the comb
is reattached and first, by hand power only, the cylinder is gently
rotated to check for proper interface with the comb.  If measurement
was done correctly it should be perfect, or require very minute
adjustment with paper shims beneath the front or rear edge of the
comb base.

Hopefully you can see now that this process is really best left to an
experienced professional.

Respectfully,

Reg Smith, Perfect Pitch Restorations
Athens, GA
706-543-1920

 [ Reg, thanks very much for sharing your knowledge with us.  I sure
 [ admire the talent and patience of you musical box restorers!  :)
 [ -- Robbie