The Talking Machine Forum — For All Antique Phonographs & Recordings

Hello, I would like to open up a general
discussion here concerning Edison diamond disc
stylus bar pins.

I am brand new to working on DD reproducers
and have just gotten one working which
previously had a badly worn diamond.

The old stylus bar with the original pin
had that pin pressed into that stylus bar
with a fit that was loose enough that I was
able to grab the end of the pin with a smooth
pliers and gently twist and pull, and it came
right out.

Not so lucky with the new stylus bar
which has the new diamond. This is supposed
to be a genuine old Edison bar, which has
been fitted with the new diamond.

The original .027 inch diameter pin fits
quite tightly in the replacment stylus bar.

Here's what I did so far: I found a sewing
needle which measures about .0265 in diameter,
being about .0005 inch less in diameter than
the original pin. Broke off the pointed
end of the needle, and the eye and made to
approximate length and rounded the ends using
a small whet stone. The resulting home made
pin appears to be from the non-tapered portion
of the needle, so it is the same diameter
everywhere along its length.

That pin fits much easier, and it will lend
itself to easy putting together and taking
apart this DD reproducer to try such things
as various tightness of the diaphragm retaining ring. It will make assembly and
disassembly a breeze each time rather than
an ordeal, which that other press fit would be.

My questions are many. What do others use
as source of stylus bar pins for DD reproducers? Why does that press fit of the
pin in the sylus bar have to be so excruciatingly tight? Seems way too tight to me.

I have the same questions and problem with
easily disassembling and reassembling
an automatic recorder. That pin is very
tight too, making the whole works a real
ordeal every time, to swap diaphragms, gaskets, or to try experiments with it.

Someone mentioned those DD stylus bar pins
here before. What is the general concensus
here about those pins?

What is wrong with choosing an easier fit?
Not by much. It is not sloppy loose or
anything like that. Just only about .0005
smaller diameter than the .027 Edison
original pin.

What are your ideas on this?

Thanks,

Chuck

The only tip I can give you regarding stylus bar pins is to make them longer than the originals so that they are much easier to remove with needle-nose pliers.

Some of your questions may have been answered in earlier posts. It's worth a quick search.

52089, Thanks for that!

Yes, on my home-made slightly looser fitting
test pin which is approximately .0005 inches
less in diameter than the Edison original pin,
I did make it a bit longer so that it has plenty of pin protruding out past the
shoulders.

I have here some special smooth pliers which
are made for adjusting relay contacts in
electro-mechanical telephone switching
equipment. I used those pliers to grab the
end of the original pin to twist and pull it out so as to remove the original stylus bar
that has the worn, damaged diamond.

However, this same pin which had a rather mild
easy press fit in that sylus bar fits quite
a bit tighter in the replacement bar.

After struggling with it for a while, I gave
up and set this pin aside, and went and found
that sewing needle, cut it off, rounded the
ends, and have been using it. It fits much
easier, and is a lot more handy for making
adjustments to this reproducer.

I am at somewhat of a disadvantage here, right
now, because currently I am at my seasonal
summer location. As such, my computer is
an ancient laptop, connected at 28.8 via
dialup. That limits my search capability
somewhat.

I brought this DD stylus bar pin question
here, so that everything about this general
issue can be in one location for future
reference. Yes, I will search, when I
have access to a faster connection.

But, in the mean time I am hoping that members here whom I know have
done extensive testing and experimentation
with all sorts of DD reproducers will chime
in and tell some of their stories.

Basically, right now, I am wondering what a
good source of nice, round, shiny, hard
steel is, that one could obtain, that would
be in a range of diameters all right around
.027 inch diameter, but slightly below.

Ideally, it would be nice to have a set
of pin material in the following
diameters:

.0270, .0269, .0268, .0267, .0266, .0265,
.0264, .0263, .0262, .0261, .0260

That way, one could choose the exact
"comfortable" fit for most any stylus bar
in most any reproducer weight.

I will be looking at tiny drill bits around
that size, both metric and english.

Any other suggestions?

Chuck

Chuck wrote: I have here some special smooth pliers which
are made for adjusting relay contacts in
electro-mechanical telephone switching
equipment.

The ones that are stamped with "Bell System?" I have those as well, and used them for this exact purpose.

Also, the better solution here is to use a #71 drill bit (turned by hand with pliers, not a drill) to widen the opening on the new stylus bar. This will allow you to use the original pin. I had to do the same thing on my replacement stylus bar.

My pliers only say "Granit" on them.
They are out of a set of Automatic Electric
tools for working on GTE step equipment.

Thanks for the tip about the #71 drill bit.

I'll get a few of those.

Chuck

If you can't find them locally (I couldn't) you can buy a vial of them for a few bucks on Amazon.

I do quite a bit of metalworking and I always
get most of my drill bits, cutting tools,
bandsaw blades, etc. from Enco or Wholesale
Tools.

http://www.useenco.com and I think
http://www.wttool.com

Enco often runs specials where they have 15%
off everything in their catalog, and some of these specials even include free ground UPS
shipping.

Chuck

A good hobby shop should carry small drill bits that work great for making DD stylus pins. I use a #71 and if it is too large I put it in a drill and wrap some #400 sandpaper around it and turn it until the size is correct. Take your stylus bar to the store and test fit some until you find the best fit, you may be able to find a size that doesn't need any adjustment.
Dave Jolley

You can buy "drill rod" in the various number drill sizes which is plain rod without the drill fluting from McMaster-Carr. I have found that the holes in Edison stylus bars are not consistent in size. They vary from about #70 to about #72 in drill size. Buy some of all three sizes from McMaster and use the one that fits your particular need.

Wow! That's a huge variation!
The drill chart lists them as:

#72 .0250
#71 .0260

Then there's .70 mm at .0276

Then #70 at .0280

I still would like to find these steel
rods in all sizes in increments of .0001
from .0260 to .0270

That's quite a range there, from .0250
up to .0280 That's a full .003 range.

What were they doing there at Edison's factory? Just drilling them any way
they felt like, on any given day?