How to choose proper cassette belt

[Eli Luong]

Hello - I am trying to repair a broken cassette player (dual-deck, one
of the larger cables that connectors to the motor is broken). I
measured it to be about 20cm or 8in. I found this website for parts:
http://www.studiosoundelectronics.com/cassette.htm

But I'm not sure what to choose exactly. They said to account for
stretch (measured the 20cm w/out stretch), but then they have 1) flat
belts, 2) square belts, 3) square belt small types. From what I can
see on my broken belt, it appears to be square shaped, 1mm in
diameter. Any guidance, please?

Thanks,
- Eli

 

[mm]

On Sat, 9 Jan 2010 16:49:39 -0800 (PST), Eli Luong
<eliluong@gmail.com> wrote:

Hello - I am trying to repair a broken cassette player (dual-deck, one
of the larger cables that connectors to the motor is broken). I
measured it to be about 20cm or 8in. I found this website for parts:
http://www.studiosoundelectronics.com/cassette.htm

But I'm not sure what to choose exactly. They said to account for
stretch (measured the 20cm w/out stretch), but then they have 1) flat
belts, 2) square belts, 3) square belt small types. From what I can
see on my broken belt, it appears to be square shaped, 1mm in
diameter. Any guidance, please?

Thanks,
- Eli

If you think it's square, it's probably square. If it measures 1mm,
it probably is.

I've had to replace one or both belts on my phone machine every 8
years or so. It uses a square belt also, less than 2mm iirc.

I couldn't get the original width, so I got the next size bigger. No
problem. It never slippped off the pully, although I'm sure if it was
wide enough it would.

I've probably gotten about 10% shorter than the measured length, and
like I say it lasts about 8 years. They sell them, or used to, at a
store here, but I ended up buying two the last time, I guess because I
thought the second belt would fail too.

Maybe if I bought shorter, it would have enough tension to last
longer, but I think it might stretch out even sooner.

Now this machine uses microcassettes and there isn't much drag on the
wheel it has to turn, even when the cassette is in place. I wonder if
you are using full size cassettes, if that would make a difference.
It might need more tension to keep the belt from slipping??? See how
hard it is to turn when the cassette is in place. Still, I don't
think I'd go below 85% of the measured length, probably measured on
the stretched out/broken belt.

The belt manual at the store gave a guideline, and it's been 18 years
since this started, but it might have said 10 to 15% shorter. Does it
say anything on the webpage you're looking at.


Right now I'm using another machine from about the same date, 1984. I
got it on ebay 2 years ago. I don't know if the belt has been changed
or not, but surely it must have been.

http://www.pyramidbelts.com/calc_beltlength.php gives a belt length
caluculator, but I don't know for what size belts.

It says "Enter stretch percentage desired (7.5, 10, 12.5%, etc.)"

I see that some are in the range our machines use.
http://www.pyramidbelts.com/fbelts.php

 

[Arfa Daily]

"mm" <NOPSAMmm2005@bigfoot.com> wrote in message
news:j9aik5p6c9ipntakntr0rl5e55tkj061u6@4ax.com...

On Sat, 9 Jan 2010 16:49:39 -0800 (PST), Eli Luong
eliluong@gmail.com> wrote:

Hello - I am trying to repair a broken cassette player (dual-deck, one
of the larger cables that connectors to the motor is broken). I
measured it to be about 20cm or 8in. I found this website for parts:
http://www.studiosoundelectronics.com/cassette.htm

But I'm not sure what to choose exactly. They said to account for
stretch (measured the 20cm w/out stretch), but then they have 1) flat
belts, 2) square belts, 3) square belt small types. From what I can
see on my broken belt, it appears to be square shaped, 1mm in
diameter. Any guidance, please?

Thanks,
- Eli

If you think it's square, it's probably square. If it measures 1mm,
it probably is.

I've had to replace one or both belts on my phone machine every 8
years or so. It uses a square belt also, less than 2mm iirc.

I couldn't get the original width, so I got the next size bigger. No
problem. It never slippped off the pully, although I'm sure if it was
wide enough it would.

This is not a problem with a telephone answering machine, where speed is not
important, but it is with an audio cassette deck. It is especially a problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't want
to be so tight that you have to really stretch it to get it on, as this can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

<snip>

 

[Eli Luong]

On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

This is not a problem with a telephone answering machine, where speed is not
important, but it is with an audio cassette deck. It is especially a problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't want
to be so tight that you have to really stretch it to get it on, as this can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

 

[Rheilly Phoull]

"Eli Luong" <eliluong@gmail.com> wrote in message
news:4f4de5d5-a662-4350-a109-541f42fcbdda@h9g2000yqa.googlegroups.com...
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

This is not a problem with a telephone answering machine, where speed is
not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as this
can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since they
are the same age presumably and to avoid doing the job again when the older
one fails.
--
Regards .............. Rheilly P

 

[hr(bob) hofmann@att.net]

On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:

On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed is not
important, but it is with an audio cassette deck. It is especially a problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't want
to be so tight that you have to really stretch it to get it on, as this can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

 

[mm]

On Sat, 9 Jan 2010 20:46:07 -0800 (PST), "hr(bob) hofmann@att.net"
<hrhofmann@att.net> wrote:

On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed is not
important, but it is with an audio cassette deck. It is especially a problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't want
to be so tight that you have to really stretch it to get it on, as this can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

That seems right to me. If there is no slippage, the speed of the
motor and the size of the two pulleys seem like the only things that
control the speed of the driven wheel. An even more extreme case is
a bicycle chain where there can be plenty of slack on the bottom, but
the top is tight.

But maybe Arfa can explain it to me.

 

[Eli Luong]

On Jan 9, 9:36 pm, "Rheilly Phoull" <rhei...@bigslong.com> wrote:

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since they
are the same age presumably and to avoid doing the job again when the older
one fails.
--
Regards .............. Rheilly P

Good point! I just have to find a local place that sells some of this
stuff...

 

[hr(bob) hofmann@att.net]

On Jan 10, 12:44 am, mm <NOPSAMmm2...@bigfoot.com> wrote:

On Sat, 9 Jan 2010 20:46:07 -0800 (PST), "hr(bob) hofm...@att.net"





hrhofm...@att.net> wrote:
On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

This is not a problem with a telephone answering machine, where speed is not
important, but it is with an audio cassette deck. It is especially a problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each marked
with a diameter. The size to pick is the next one down from where the belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't want
to be so tight that you have to really stretch it to get it on, as this can
rapidly cause bearing wear, and stop idler arms from swinging, where these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

That seems right to me.  If there is no slippage, the speed of the
motor and the size of the two pulleys seem like the only things that
control the speed of the driven wheel.   An even more extreme case is
a bicycle chain where there can be plenty of slack on the bottom, but
the top is tight.

But maybe Arfa can explain it to me.- Hide quoted text -

- Show quoted text -

EXACTLY!!!

 

[Michael A. Terrell]

Eli Luong wrote:

On Jan 9, 9:36 pm, "Rheilly Phoull" <rhei...@bigslong.com> wrote:

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since they
are the same age presumably and to avoid doing the job again when the older
one fails.
--
Regards .............. Rheilly P

Good point! I just have to find a local place that sells some of this
stuff...

I found this place the other day: http://www.turntableneedles.com/

They appear to use the old PRB measuring system. PRB had a cross
refference by brand and model number. Check and see if thay have updated
it to include your unit.

I've never dealt with them, but finding belts is getting harder and
harder. Most of the old suppliers are out of business.


--
Greed is the root of all eBay.

 

[David]

In article
<d0175230-4dad-4108-9c08-d898a9bc2c8f@j5g2000yqm.googlegroups.com>,
Eli Luong <eliluong@gmail.com> wrote:

Hello - I am trying to repair a broken cassette player (dual-deck, one
of the larger cables that connectors to the motor is broken). I
measured it to be about 20cm or 8in. I found this website for parts:
http://www.studiosoundelectronics.com/cassette.htm

But I'm not sure what to choose exactly. They said to account for
stretch (measured the 20cm w/out stretch), but then they have 1) flat
belts, 2) square belts, 3) square belt small types. From what I can
see on my broken belt, it appears to be square shaped, 1mm in
diameter. Any guidance, please?

Thanks,
- Eli

Dick Smith Electonics (DSE.com.au) sell a package of belts of varying
sizes - probably will be one in the package that suits

David

 

[Mark Zacharias]

"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:eb7be913-0fab-4a5f-a73e-ab951acb4287@u7g2000yqm.googlegroups.com...
On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:

On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed is
not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both
belts
are not the same dimension across the section, then one deck will run at
a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the
belt
sits on the chart. Most cassette decks don't mind too much if the belt
is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as this
can
rapidly cause bearing wear, and stop idler arms from swinging, where
these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

If it's square-cut it does. Seen it many times.

Mark Z.

 

[Arfa Daily]

"mm" <NOPSAMmm2005@bigfoot.com> wrote in message
news:mitik5tt3vdtnk3er9bgq9g4b4pr9aqifu@4ax.com...

On Sat, 9 Jan 2010 20:46:07 -0800 (PST), "hr(bob) hofmann@att.net"
hrhofmann@att.net> wrote:

On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed
is not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both
belts
are not the same dimension across the section, then one deck will run
at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into
a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the
belt
sits on the chart. Most cassette decks don't mind too much if the belt
is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as
this can
rapidly cause bearing wear, and stop idler arms from swinging, where
these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

That seems right to me. If there is no slippage, the speed of the
motor and the size of the two pulleys seem like the only things that
control the speed of the driven wheel. An even more extreme case is
a bicycle chain where there can be plenty of slack on the bottom, but
the top is tight.

But maybe Arfa can explain it to me.

The size of the belt section *does* matter. If one belt is of smaller
section than the other, they will ride at different points on their drive
pullies and capstans. This effectively alters the diameters of the pullies
with respect to one another, making one deck run at a slightly different
speed to the other. It's not a lot, granted, but certainly enough to hear,
and most definitely enough to see on a speed-test strobe tape. Sometimes, if
not using manufacturer's original belts, there is no option but to use
different section-size belts on the two decks in order to get the correct
length-sizes. When this is the case, any speed differences can be removed
enough to not hear them, by adjusting the motor speed such that one deck is
running very slightly slow, and the other very slightly fast. All this of
course, refers *only* to dual decks driven by a single motor - for instance
the hundreds of Aiwa models with the three and five CD carousel units in the
top, that were popular barn items a few years back. Where each deck is
driven by its own motor, then the speeds can be set independantly.

Whenever a main drive belt is replaced on any cassette deck, the speed
should be checked anyway, purely as a matter of good and professional repair
practice ...

Arfa

 

[Arfa Daily]

"Rheilly Phoull" <rheilly@bigslong.com> wrote in message
news:U-OdnfADrOHR-tTWnZ2dnUVZ_jWdnZ2d@westnet.com.au...

"Eli Luong" <eliluong@gmail.com> wrote in message
news:4f4de5d5-a662-4350-a109-541f42fcbdda@h9g2000yqa.googlegroups.com...
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
This is not a problem with a telephone answering machine, where speed is
not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both belts
are not the same dimension across the section, then one deck will run at
a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the
belt
sits on the chart. Most cassette decks don't mind too much if the belt is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as this
can
rapidly cause bearing wear, and stop idler arms from swinging, where
these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since
they are the same age presumably and to avoid doing the job again when the
older one fails.
--
Regards .............. Rheilly P

Agreed, and see my reply to Bob further up the thread

Arfa

 

[Arfa Daily]

"Mark Zacharias" <mark_zacharias@sbclobal.net> wrote in message
news:00a8bb53$0$8158$c3e8da3@news.astraweb.com...

"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:eb7be913-0fab-4a5f-a73e-ab951acb4287@u7g2000yqm.googlegroups.com...
On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed
is not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both
belts
are not the same dimension across the section, then one deck will run
at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into
a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the
belt
sits on the chart. Most cassette decks don't mind too much if the belt
is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as this
can
rapidly cause bearing wear, and stop idler arms from swinging, where
these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.


If it's square-cut it does. Seen it many times.

Mark Z.

Thanks, Mark

Arfa

 

[Arfa Daily]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:_8udnUFFMdc3gNfWnZ2dnUVZ_uNi4p2d@earthlink.com...

Eli Luong wrote:

On Jan 9, 9:36 pm, "Rheilly Phoull" <rhei...@bigslong.com> wrote:

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since
they
are the same age presumably and to avoid doing the job again when the
older
one fails.
--
Regards .............. Rheilly P

Good point! I just have to find a local place that sells some of this
stuff...


I found this place the other day: http://www.turntableneedles.com/

They appear to use the old PRB measuring system. PRB had a cross
refference by brand and model number. Check and see if thay have updated
it to include your unit.

I've never dealt with them, but finding belts is getting harder and
harder. Most of the old suppliers are out of business.

Same this side of the pond. I have a row of probably 30 nails in the wall at
the back of the bench, each marked for a different size of drive belt, with
the smaller sizes going up in one and two mm steps. I used to be able to
keep these stocked from several suppliers without any problem at all. Now
there are only a couple that keep them, and as they run out of stock of any
size, they do not seem to replace them - or maybe they can't obtain them
themselves. I would guess that at least a third of my nails are now either
empty, or down to one or two belts from the ten minimum that I used to keep
....

Arfa

 

[Sansui Samari]

On Jan 11, 12:52 am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

"Michael A. Terrell" <mike.terr...@earthlink.net> wrote in messagenews:_8udnUFFMdc3gNfWnZ2dnUVZ_uNi4p2d@earthlink.com...





Eli Luong wrote:

On Jan 9, 9:36 pm, "Rheilly Phoull" <rhei...@bigslong.com> wrote:

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli

If you have it down it would be foolish not to replace both belts since
they
are the same age presumably and to avoid doing the job again when the
older
one fails.
--
Regards .............. Rheilly P

Good point! I just have to find a local place that sells some of this
stuff...

  I found this place the other day:http://www.turntableneedles.com/

  They appear to use the old PRB measuring system. PRB had a cross
refference by brand and model number. Check and see if thay have updated
it to include your unit.

  I've never dealt with them, but finding belts is getting harder and
harder. Most of the old suppliers are out of business.

Same this side of the pond. I have a row of probably 30 nails in the wall at
the back of the bench, each marked for a different size of drive belt, with
the smaller sizes going up in one and two mm steps. I used to be able to
keep these stocked from several suppliers without any problem at all. Now
there are only a couple that keep them, and as they run out of stock of any
size, they do not seem to replace them - or maybe they can't obtain them
themselves. I would guess that at least a third of my nails are now either
empty, or down to one or two belts from the ten minimum that I used to keep
...

Arfa

I wonder how difficult it would be to produce rubberized belts.
Anyone know if they were mold injected or extruded and joined at the
ends, or anything about the process. I work in a mold injection plant
right now, so even if it's not feasible, it would still be interesting
for me, to know the process.

 

[mm]

On Mon, 11 Jan 2010 08:45:42 -0000, "Arfa Daily"
<arfa.daily@ntlworld.com> wrote:

"mm" <NOPSAMmm2005@bigfoot.com> wrote in message
news:mitik5tt3vdtnk3er9bgq9g4b4pr9aqifu@4ax.com...
On Sat, 9 Jan 2010 20:46:07 -0800 (PST), "hr(bob) hofmann@att.net"
hrhofmann@att.net> wrote:

On Jan 9, 8:37 pm, Eli Luong <elilu...@gmail.com> wrote:
On Jan 9, 5:46 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:





This is not a problem with a telephone answering machine, where speed
is not
important, but it is with an audio cassette deck. It is especially a
problem
if it is a dual deck machine, but driven by a single motor. If both
belts
are not the same dimension across the section, then one deck will run
at a
different speed to the other. Even a small discrepancy can cause a
significant speed error. As far as picking a size goes, many belt
manufacturers quote the sizes as a diameter when the belt is made into
a
nice circle. I have a chart with many concentric circles on it, each
marked
with a diameter. The size to pick is the next one down from where the
belt
sits on the chart. Most cassette decks don't mind too much if the belt
is
slightly tight, and in general, better that than loose, but it doesn't
want
to be so tight that you have to really stretch it to get it on, as
this can
rapidly cause bearing wear, and stop idler arms from swinging, where
these
rely on light belt tension to form their spring return.

Arfa

snip

Thanks. It does look like it's driven by just one motor. What you said
suggests I would have to change both belts at the time time, in order
to keep the cassette decks running at the same speed? If I change both
belts, and it differs a little bit, would that mean I would have to
readjust the speed of the motor? The service manual for the shelf
stereo mentions speed adjustment of the tape deck.

- Eli- Hide quoted text -

- Show quoted text -

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

That seems right to me. If there is no slippage, the speed of the
motor and the size of the two pulleys seem like the only things that
control the speed of the driven wheel. An even more extreme case is
a bicycle chain where there can be plenty of slack on the bottom, but
the top is tight.

But maybe Arfa can explain it to me.

The size of the belt section *does* matter. If one belt is of smaller
section than the other, they will ride at different points on their drive
pullies and capstans. This effectively alters the diameters of the pullies
with respect to one another, making one deck run at a slightly different

And indeed, you convinced me. Thanks.

speed to the other. It's not a lot, granted, but certainly enough to hear,
and most definitely enough to see on a speed-test strobe tape. Sometimes, if
not using manufacturer's original belts, there is no option but to use
different section-size belts on the two decks in order to get the correct
length-sizes. When this is the case, any speed differences can be removed
enough to not hear them, by adjusting the motor speed such that one deck is
running very slightly slow, and the other very slightly fast. All this of
course, refers *only* to dual decks driven by a single motor - for instance
the hundreds of Aiwa models with the three and five CD carousel units in the
top, that were popular barn items a few years back. Where each deck is
driven by its own motor, then the speeds can be set independantly.

Whenever a main drive belt is replaced on any cassette deck, the speed
should be checked anyway, purely as a matter of good and professional repair
practice ...

Arfa

 

[Arfa Daily]

<snip>

Unless the belt actually is slipping, the belt size does not effect
the actual speed.

That seems right to me. If there is no slippage, the speed of the
motor and the size of the two pulleys seem like the only things that
control the speed of the driven wheel. An even more extreme case is
a bicycle chain where there can be plenty of slack on the bottom, but
the top is tight.

But maybe Arfa can explain it to me.

The size of the belt section *does* matter. If one belt is of smaller
section than the other, they will ride at different points on their drive
pullies and capstans. This effectively alters the diameters of the pullies
with respect to one another, making one deck run at a slightly different


And indeed, you convinced me. Thanks.

.... No probs. A good example just occured to me. Do you remember the "DAF
Variomatic" auto transmission ? This was a belt-drive system able to provide
continuously variable 'gear' ratios by squeezing the sides of the pullies
together or allowing them to part differentially, which altered the point at
which the belt 'rode', effectively altering the ratio of one pulley
diameter, to the other.

see http://www.youtube.com/watch?v=R8AzqtomwD0

Arfa

 

[Chuck]

On Sat, 9 Jan 2010 16:49:39 -0800 (PST), Eli Luong
<eliluong@gmail.com> wrote:

Hello - I am trying to repair a broken cassette player (dual-deck, one
of the larger cables that connectors to the motor is broken). I
measured it to be about 20cm or 8in. I found this website for parts:
http://www.studiosoundelectronics.com/cassette.htm

But I'm not sure what to choose exactly. They said to account for
stretch (measured the 20cm w/out stretch), but then they have 1) flat
belts, 2) square belts, 3) square belt small types. From what I can
see on my broken belt, it appears to be square shaped, 1mm in
diameter. Any guidance, please?

Thanks,
- Eli
A word of caution. We discovered years ago that using PRB square

belts would greatly increase the deck's wow and flutter so I would
avoid them. Chuck