Dear Diyers,
to my knowledge, the Nakamichi OMS-7/7II and OMS-5/5II and Kyocera-DA 910
are the only CD-player ever built to use a belt driving the laser.
The Kyocera-DA910 and the Nakamichi OMS-7/5 use a Toshiba Laser,
The OMS 7II/5II use a Sony laser but the mechanics besides the disc motor
are the same. The belts wear and the original belt can even detoriate to tar over he years,
I had one OMS-5II with the symptom.
Replacements belts are still available but probably old stock.
Time to find out whether it can be replaced with gear.
The good news: It can, no difference to the original setup.
The bad news: While being silent like the original setup during playback,
the brass gear makes an annoying sound during skip and search or when
returning to the start position.
If it was a a rich sound, a confirming sturdy "rrrt" like
my Sony CDP-101 I would not care.
But it is a grinding, rattling noise
When I heard it first, I thought something
was broken - but everything is fine.
This annoyance could have been avoided with POM/Plastic gear,
but I wanted to heat-shrink a brass gear on the motor-shaft,
as POM cannot be glued.
I did dot want to try a mixture of brass and POM.
But again, complete silence during playback.
There are some obstacles:
Heat shrinking gear on a shaft means tight tolerances.
With the help of a friend, we experimended with reamers
until we found one, that was a tad smaller in diameter than the others.
A tad means here 1/100mm. Even the oil used for cutting makes a difference.
But after 5 gears were wasted, we found the right reamer.
Motor in the freezer over night, heat the brass gear with your soldering iron,
slam the motor on the gear et voilá, better than any glue.
The the big gear has to be milled exactly to fit on the part
that originally holds the belt.. But after that, everything is simple.
When soldering the wires vor the voltage back on the modified motor,
polarity has to be reversed, as the gear does not turn with the motor
but against it...
In the attached video "GearInAction" heavily scratched CD is played,
so more tracking correction takes place. I do some skip, search and finally stop.
But he music in the background is from another player.
But bottom line - It works and replacing the big brass gear with one made of POM
will very likely defeat the noise during skip and search...
to my knowledge, the Nakamichi OMS-7/7II and OMS-5/5II and Kyocera-DA 910
are the only CD-player ever built to use a belt driving the laser.
The Kyocera-DA910 and the Nakamichi OMS-7/5 use a Toshiba Laser,
The OMS 7II/5II use a Sony laser but the mechanics besides the disc motor
are the same. The belts wear and the original belt can even detoriate to tar over he years,
I had one OMS-5II with the symptom.
Replacements belts are still available but probably old stock.
Time to find out whether it can be replaced with gear.
The good news: It can, no difference to the original setup.
The bad news: While being silent like the original setup during playback,
the brass gear makes an annoying sound during skip and search or when
returning to the start position.
If it was a a rich sound, a confirming sturdy "rrrt" like
my Sony CDP-101 I would not care.
But it is a grinding, rattling noise
When I heard it first, I thought something
was broken - but everything is fine.
This annoyance could have been avoided with POM/Plastic gear,
but I wanted to heat-shrink a brass gear on the motor-shaft,
as POM cannot be glued.
I did dot want to try a mixture of brass and POM.
But again, complete silence during playback.
There are some obstacles:
Heat shrinking gear on a shaft means tight tolerances.
With the help of a friend, we experimended with reamers
until we found one, that was a tad smaller in diameter than the others.
A tad means here 1/100mm. Even the oil used for cutting makes a difference.
But after 5 gears were wasted, we found the right reamer.
Motor in the freezer over night, heat the brass gear with your soldering iron,
slam the motor on the gear et voilá, better than any glue.
The the big gear has to be milled exactly to fit on the part
that originally holds the belt.. But after that, everything is simple.
When soldering the wires vor the voltage back on the modified motor,
polarity has to be reversed, as the gear does not turn with the motor
but against it...
In the attached video "GearInAction" heavily scratched CD is played,
so more tracking correction takes place. I do some skip, search and finally stop.
But he music in the background is from another player.
But bottom line - It works and replacing the big brass gear with one made of POM
will very likely defeat the noise during skip and search...
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I did not want to start with a mixture of brass (small gear, because of heat shrinking)
and plastic (big gear).
I also wanted to take avantage of inertia (the big gear weights 60grams)
as it might come closer to a belts' behaviour.
A threaded hole in brass is also better than in POM.
But a replacement with a gear made from POM is already set.
I just need to find a POM gear in the thickness of 5-6mm.
and plastic (big gear).
I also wanted to take avantage of inertia (the big gear weights 60grams)
as it might come closer to a belts' behaviour.
A threaded hole in brass is also better than in POM.
But a replacement with a gear made from POM is already set.
I just need to find a POM gear in the thickness of 5-6mm.
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POM gear is ordered, but only for the big gear.
Any tips about the combination of Brass and POM?
The grease I use for about a decade is from Panasonic,
RFKXPG671, one pot lasts a life,probably silicone,
white, extremely stable to temperature. You can hold
a flame beneath it and no change in viscosity.
It does not become clear like Vaseline would.
It was made for lubricating the rails and gear of Panasonic players.
I assume this will be suitable for combining POM with Brass?
Best,
Salar
Any tips about the combination of Brass and POM?
The grease I use for about a decade is from Panasonic,
RFKXPG671, one pot lasts a life,probably silicone,
white, extremely stable to temperature. You can hold
a flame beneath it and no change in viscosity.
It does not become clear like Vaseline would.
It was made for lubricating the rails and gear of Panasonic players.
I assume this will be suitable for combining POM with Brass?
Best,
Salar
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