Edison Triumph D suddenly stopped tracking

[Schlick]

I just got my Triumph put together with a reproducer the last couple of days and have been enjoying listening to my cylinders when all of the sudden a 4 minute record started skipping.

Upon inspection, now all records skip in all spots. In fact the carriage wont even track when there is no record. Tried a bit more oil on the back carriage slider bar, which made the carriage slide much easier, but it still won't track by the screw drive.

I can hear the carriage race skipping on the screw drive with and without a record present.

Any ideas what is happening / has happened?

Thank you for any insight!

-Michael Schlick

[rizbone]

Maybe some goop in the half-nut?

[Phonofreak]

Check the half-nut and feedscrew to see if there is dirt like rizbone said. Another thing to check is to make sure the half-nut is engaging the feedscrew.
Harvey Kravitz

[Schlick]

Thanks Phonofreak and Rizbone!

I cleaned and oiled the feed screw and the half nut.
I twisted the cygnet horn crane to face the front (it had worked its way ~20 deg off).
I adjusted the horn suspension screw to take as much horn weight off the reproducer as possible.
I reshaped by hand the half nut spring bar such that it applies more pressure to the half nut when in the playing position.(Is there a correct "setting" for this?)

And it works better, but still can't make it all the way, the half nut jumps threads and the carriage stops (in different places).

(The half nut threads look really shallow to me. And I noticed the last ~¼-½" of the feed screw threads are damaged as if something dropped on it - And I don't have a reamer and some records don't fit all the way on the mandrill so I have played a few all the way over that end. Maybe that explains the suddenness?)

New half nut assembly, maybe?

[Chuck]

The halfnut needs to ride on the feedscrew with a slight
pressure. The whole idea of the way that is all supposed
to work is that the halfnut threads need to fully engage
with the feedscrew threads. While maintaining this positive engagement, there also must be a minimum of
friction.

On some machines, this precise combination of things
is easier to obtain, than on some other machines.

Some of the ones I have seen have a small adjuster screw
which can be turned to increase or to decrease the
pressure of the halfnut against the feedscrew.

The best possible arrangement is to have the halfnut
mounted on a very springy piece of steel so that when
it touches the feedscrew, and the carriage continues down
a little farther, the flat spring bends a little bit,
pushing the halfnut gently against the feedscrew.

That arrangement assures positive engagement, and it
also takes care of keeping the forces low, and so the
friction is also kept low.

For some oddball reason, Edison designed some of
those halfnut assemblies with a very solid fit, without
being springy hardly at at all. Those kind are very
difficult to adjust properly because the adjustment
has very little acceptable working range. It has to
be exactly right to work correctly.

The particular halfnut assembly on my Edison standard
model D combination 2/4 machine was one of those
solid type. I finally got tired of it being that
way, so I non-destructively changed it so it has
a piece of spring-metal pushing gently on the halfnut
now. Works very well that way.

The feedscrew and halfnut do need a liberal amount
of oil on them to work correctly. I use relatively
thick 20W50 engine oil in an eyedropper bottle and
always keep a few drops on the feedscrew so it is
always visibly wet with oil.

The halfnut should touch the feedscrew just before the
carriage touches the flat guide bar in front.
Edison said the halfnut just "kisses" the feedscrew.

Hope this helps some.

Can you post some pictures?

Chuck

[Lucius1958]

It might also be possible that the half nut has 'given up the ghost', after years of wear from a feedscrew that has been exposed to dust and dirt.

I had this problem with my Home: after some years, it began having problems with tracking. When I examined it closely, the half nut had been reduced to the consistency of Shredded Wheat®...

Bill

[Bob]

You can also try adjusting the half nut by loosening the 2 screws that hold it on. Clean the gunk from around it so it has more movement. Turn it on and get the feed screw moving. Drop the carriage down and seat the half nut to the feed screw. Put some light pressure on the half nut to get it seated into the threads of the feed screw. Tighten the 2 screws. This will assure you have the best alignment between the 2 threaded surfaces.
Bob

[phonogfp]

Also, be sure you don't have the cygnet suspension too light, or it will lift the half nut off the feedscrew at one or both ends.

George P.

[VintageTechnologies]

The reproducer carriage of my Triumph has a split flat spring that holds two feed nuts. I don't recall if all Triumphs have that feature, so I can't comment too specifically about yours. All of the Homes have a single feed nut, so I will make a few general statements about those, which may not necessarily apply to Triumphs.

1) As already mentioned, check that the threads of the feed nut are in good condition. I have a few that were badly worn from use or had the threads completely wiped out by misalignment of the flat spring. New replacements are extremely inexpensive.

2) By misalignment, I mean to say that on the Home phonograph where the flat spring attaches to the reproducer carriage, it is attached by a couple of screws. It is possible for those screws to lose their grip on the flat spring so that the flat spring (and feed nut) is not perfectly perpendicular to the feed screw. (The Triumph carriage may have improvements that prevent misalignment. Sorry, I can't check my machine right now to be certain of that.) The slightest angle of misalignment from perpendicular can cause tracking problems and the obliteration of the feed nut threads. I simply loosen those screws and realign the nut into the grooves of the feed screw "by feel". Then I tighten those screws again.

3) I would try to remedy the damaged feed screw or replace it. With some powerful jeweller's glasses and small needle files, it might be possible to clean up the feed screw by filing down any protrusions and clearing out deformed metal inside the threads. I have also seen people as last resort clear heavy rust and gunk from the threads by holding lightly the corner of a Gem razor blade into the threads, down the entire length of a running feed screw, over and over again.

[TonyJ]

I apologize in advance if this is a silly "newbie" question as I never really looked at a cylinder player in any great detail. If Edison machines utilize a feed screw for the reproducer travel as I'm imagining it for the cylinder and disc players, as long as the feed screw or this half nut isn't damaged, is it possible to ever have a skipping record, or is there some play where the stylus could skip a damaged groove or two without simply "plowing through" the damaged area? The other concept I'm having a hard time with is how the record grooves "get aligned" so to speak with the feed screw so that the stylus is centered in the groove when the record is loaded and engaged. I'm picturing setting the stylus down and the feed screw somehow in a position with respect to the recording where the stylus isn't inside the groove but over a raised edge. There must be some lateral give and take on the stylus, correct?

I've ordered a copy of the Compleat Talking Machine book and it should be here any day, so hopefully no more of these questions