Re: Fixing a Recorder
Posted: Tue Jan 27, 2015 3:16 am
My opinion of any recorder weight assembly which
has the diaphragm mounted to it probably needs the
diaphragm removed so as to allow access inside
to clean all the dirt out.
Most often these old recorders have some amount
of wax dust and other dirt lodged between the diaphragm
and the top inside of the chamber. Keep in mind that
the chamber over the diaphragm is only .018 or .019
inches tall, being set by the thickness of the gasket.
Add to that the fact that most of these old recorders
also need the beeswax bead around the diaphragm reworked
anyway.
So, it's really just about as easy to simply disassemble
the whole works, then clean it all up and start fresh.
Driving the hinge pivot pin in and out, and especially
getting it back in there so that the weight swings
freely, but with absolutely no side-play can be
tricky and it takes time.
Usually when the pin is installed, the weight will
either bind or have too much side play. Turning
the pin a few degrees at a time and reassembling
will usually result in finding the correct fit.
I use a small drillpress vise in which I put some
.0625 inch thick soft aluminum angles so as to
protect the recorder body as it is clamped in.
Place the recorder body in the vise tube-up as it
would be when installed in the phonograph.
Use the vise to grab the smaller diameter of the
body just below the larger diameter lip. The body
can be grasped firmly this way with the lip resting
on the tops of the vise jaws. That way, the pin can be
gently tapped in and out using the appropriate
diameter of brass or steel wire to push it while
tapping gently with a very small ballpeen hammer.
The key idea here is to be gentle and also careful
to use tools which will not mark or scratch the
original Edison parts. Use only enough force to
drive the pin out. If it sticks or binds, stop and
think it over before applying any more force.
Be careful and slow.
Using a wire which is slightly smaller than the
pivot pin diameter allows the pin to be pushed
after it recedes into the hole in the recorder body.
I'd be very wary of trying to fit a different
weight to a recorder body than the one it left the
factory with. Changing those sets around is really
asking for trouble as fas as either binding the weight
or ending up with free-swinging but with a bunch
of side-play. Those sets were fit up at the factory.
The first ingredient to rebuilding one of these recorders is to get the weight swinging freely
with no side play. Also have the sliding tube
sliding very very freely. Polish the inside of
the sound tube. Once this whole assembly is
working freely, and is all cleaned up, then it is
time to put in the bottom gasket and set the diaphragm
in.
If a diaphragm can be used that already has the
stylus holder firmly cemented to it, that might work
ok. But I have not seen one yet which has not
needed to be reglued. Some of those copper stylus
holders are anchored to the diaphragm with 2 tiny
copper tabs which poke through the diaphragm and are
bent down on the other side.
Watch for that if you try to get one apart. Those
with the tabs need to have the tabs bent up in order
to safely take it apart, otherwise a big hole will
be torn in the diaphragm.
It all makes sense after you do the first few
recorders. Those first few are a learning experience
though.
Chuck
has the diaphragm mounted to it probably needs the
diaphragm removed so as to allow access inside
to clean all the dirt out.
Most often these old recorders have some amount
of wax dust and other dirt lodged between the diaphragm
and the top inside of the chamber. Keep in mind that
the chamber over the diaphragm is only .018 or .019
inches tall, being set by the thickness of the gasket.
Add to that the fact that most of these old recorders
also need the beeswax bead around the diaphragm reworked
anyway.
So, it's really just about as easy to simply disassemble
the whole works, then clean it all up and start fresh.
Driving the hinge pivot pin in and out, and especially
getting it back in there so that the weight swings
freely, but with absolutely no side-play can be
tricky and it takes time.
Usually when the pin is installed, the weight will
either bind or have too much side play. Turning
the pin a few degrees at a time and reassembling
will usually result in finding the correct fit.
I use a small drillpress vise in which I put some
.0625 inch thick soft aluminum angles so as to
protect the recorder body as it is clamped in.
Place the recorder body in the vise tube-up as it
would be when installed in the phonograph.
Use the vise to grab the smaller diameter of the
body just below the larger diameter lip. The body
can be grasped firmly this way with the lip resting
on the tops of the vise jaws. That way, the pin can be
gently tapped in and out using the appropriate
diameter of brass or steel wire to push it while
tapping gently with a very small ballpeen hammer.
The key idea here is to be gentle and also careful
to use tools which will not mark or scratch the
original Edison parts. Use only enough force to
drive the pin out. If it sticks or binds, stop and
think it over before applying any more force.
Be careful and slow.
Using a wire which is slightly smaller than the
pivot pin diameter allows the pin to be pushed
after it recedes into the hole in the recorder body.
I'd be very wary of trying to fit a different
weight to a recorder body than the one it left the
factory with. Changing those sets around is really
asking for trouble as fas as either binding the weight
or ending up with free-swinging but with a bunch
of side-play. Those sets were fit up at the factory.
The first ingredient to rebuilding one of these recorders is to get the weight swinging freely
with no side play. Also have the sliding tube
sliding very very freely. Polish the inside of
the sound tube. Once this whole assembly is
working freely, and is all cleaned up, then it is
time to put in the bottom gasket and set the diaphragm
in.
If a diaphragm can be used that already has the
stylus holder firmly cemented to it, that might work
ok. But I have not seen one yet which has not
needed to be reglued. Some of those copper stylus
holders are anchored to the diaphragm with 2 tiny
copper tabs which poke through the diaphragm and are
bent down on the other side.
Watch for that if you try to get one apart. Those
with the tabs need to have the tabs bent up in order
to safely take it apart, otherwise a big hole will
be torn in the diaphragm.
It all makes sense after you do the first few
recorders. Those first few are a learning experience
though.
Chuck