1956 Zenith Cobra-Matic Stroboscope Changer Transition

[Hi-Fi-Mogul]

I was able after some effort to remove the
Stroboscope from the Zenith HFY-17 consolette.

So, looking at the correct year 1956 changer manuals,
they don't align with this changer S-14067.

This one has a belt-drive drive wheel/idler wheel
assembly that is only shown on the 1958 Sams.

The manufacture stamp date of the changer is DEC 1955.

The record support arm is also the style for the 1956.
There are as well as a few other stylistic differences.

It would be nice for there to be manufacturer data change
sheets for record changers.

[Ken Doyle]

There's a changer in the 1953 Beitman's manual starting on page 171 that may be close your yours.

https://worldradiohistory.com/Beitman-Manual.htm

[Hi-Fi-Mogul]

There's a changer in the 1953 Beitman's manual starting on page 171 that may be close your yours.

Thanks Ken, I have that file.
There is no drive belt used in those models.

I've contacted Gary at the V of Music, but I
know I'll have to measure the belt.

And hope there is a belt that will fit it.

[Hi-Fi-Mogul]

Gary came right back with the belt size I need.
He is amazing !

[William]

Yes, he is!

Bill

[Hi-Fi-Mogul]

Well another event I've never experienced.

I put the Cobramatic S-14067 changer on the work table, and
was reviewing its innards.

When I removed the record spindle assembly for
cleaning, something in the spindle didn't seem correct.

It's missing the part that allows the record to drop off
the spindle shelf.

I don't even know what the part looks like, because the
dang changer diagram gives no image of how the
spindle itself is composed.

The Voice of Music site indicates the spindle is not
in stock.
I emailed Gary anyway in meager hopes that he might have
one or a used one sitting around.

This is so disappointing, since I have the amp and cabinet
all ready to go.

I used up a 3 mos supply of cussin', ha ha !!

[TC Chris]

Can you reverse-engineer the part by studying the related parts--how they move during the cycle, what needs to happen to make the record move over and drop--and fabricate a replacement by cutting & grinding?

Chris Campbell

[Hi-Fi-Mogul]

I don't have the tools or expertise to try and fabricate
that part, which I have not seen.
The spindle does not operate like 99% of others.

But, I found a 1954 parts donor item that I asked the
Zenith owners to purchase.
I looked up the model #, and checked it against the
spindle number in this Zenith.
They should be the same.

That item has sold, so I hope my customers bought it.

This Zenith is more complex, as I had a premonition about.

I did make progress today on starting the dis-assembly.

I was a bit leery about removing the tonearm,
but it had to come off to remove the plastic
housing.
After observation, I found I did not have to fiddle with
the underside of the tonearm mechanism, which can
create more functional problems.

And during that dis-assembly start, I also saw there may be
more parts that will need replacement from the donor
Cobramatic changer.

In the bottom of photo, you can view the belted drive wheel,
with the belt around the motor spindle.

[TC Chris]

So the belt drives that horizontal disc, which in turn drives a vertical idler that drives the underside of the turntable?

Chris Campbell

[William]

My question would be, how or way was that part of the spindle removed. Not that really makes any difference what's done is done. It's a good thing you found a donor changer and keeping one's fingers crossed that your customer purchased it.

Bill

[Hi-Fi-Mogul]

Good news: the Zenith parts unit is on its way to me !

Chris,
Yes, the vertical idler/speed control sliding mech is
over in the parts pan.

Bill,
Of course I had the same question.
Without knowing yet what that complete spindle
looks like, I could not see how the part
could be missing.

I had a positive thought that since this is a
belt drive, I don't think I will need to order
a replacement drive wheel that the belt
runs.

I already have the belt, so when I get the mech
clean and lubed, I can test that out.

[electra225]

What Bill said. WHY would someone remove that part? I wonder if it broke somehow and just fell out and got lost. Could you dis-assemble that spindle if you wanted to? Is that even possible?

[Hi-Fi-Mogul]

Greg,
Yes, the spindle right now has only 2 parts.
A plunger and the spindle body.

Look back earlier in these posts and you will see the
photo of it.

There is obviously some part(s) that go at the top end of
the spindle plunger.
It has a point on its top end that engaged something.

[electra225]

Thanks for filling me in, Mr. Mogul. I didn't understand that the spindle is actually a piece that slides down over another piece. So how does/did the "pusher" part fit into that spindle? Do you have a theory as to why it's gone? So, the little piece that sticks up out of the piece on the left moves/lifts when the changer cycles, that moves the piece that is missing, which knocks the record off the shelf. Have I got this close to correct? I'm trying to understand how this works, so please pardon any silly questions.....

[Hi-Fi-Mogul]

Greg,
I'm about as stumped as anyone else here, ha ha !

From listening to video commentary on these,
the action of this spindle part is a lateral turning or
twisting.
With every part in place, that twist action is what
pushes the record off of the spindle shelf.

"All will be revealed" (I hope) when the parts unit
arrives.

I'm starting to have a lot more interest in this changer.

The record change and trip pawl actions are activated by an electromagnet !
You can see the transformer there that is for the magnet coil.

I have not ruminated on that yet, until all is cleaned up.

This is a deep one.

[Hi-Fi-Mogul]

Made good progress with cleaning the cycling mech.

The clutch gear assembly was frozen in place due to
old grease.

You can see that belt hasn't turned in some decades !

I may take the motor off the board tonight for cleaning,
but I'll only have a short length of its wires to work with.

I don't want to disconnect that complex of wiring if I can
avoid it.

I'll set the motor on some boxes, like I do with the Collaros.

[William]

Mr. Mogul. What's the little transformer do? Was this early version of the Coberamatic Zenith designed and built?

Bill

[Hi-Fi-Mogul]

Mr. Mogul. What's the little transformer do? Was this early version of the Coberamatic Zenith designed and built? Bill

All these Cobramatics until 1958 were in-house Zenith.

Zenith went to a high-level in-house belt-drive with the
built in clam-shell 45 adapter later, until the mid-60's.
It was the first of the MicroTouch 2G changers.

In-between, on many units, there were V-M changers.
A 1958 Zenith Cobra tonearm design used a V-M 1200 series.

RE: transformer, see my post to Greg on this page.

[William]

Thanks, Mr. Mogul, I guess I missed that.

Bill

[Hi-Fi-Mogul]

The motor is clean, lubed, and mounted on the motor board.

It was very easy, as there were not spacers to contend with.

The rotor has 2 fans on the upper and lower areas.

The rubber mounts are large like on Webcors, but not as tall as
Magnavox.
I don't see a need to replace them.

Yesterday I cleaned up the idler wheel and its
bracket assembly.
The manual notes that graphite grease is to be used.

Man, that stuff was really hardened as if over heated.

The drive wheel and its bracket/bushing/stud
assembly were cleaned and lubed.

The little idler wheel has 2 large very flat spots.
Will need to send to V of Music for exchange.