I'm trying to recondition an Akai GXC760D Hifi cassette deck
(late 70's vintage I believe.)

This is a twin capstan (both engaged at once) design that uses
11.0mm diameter pinch rollers. The diameter is quite critical
as there is only just enough travel on the carriage, the
clearances are tight, and I think the nature of a twin
capstan design makes pinch roller pressure fairly critical.
The common replacement sizes (9.6mm and 13.0mm) do not fit.
I think an acceptable range would probably be 10.5-11.5mm.

The height is 7.9mm and hole diameter 2.5mm, though these
are somewhat negotiable.

I've looked through a variety of usual UK parts sources
(RS CPC/Farnell Grandata CharlesHyde Seme etc)
and I get the feeling nobody stocks other than the two
'standard' sizes.

Anyone know of somewhere that stocks 11.0mm? Anywhere
in the world (though UK would be ideal.)

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.
Or maybe, if a VCR pinch roller of the right diameter existed
(is there a table of VCR model to diameter anywhere??) then
as these seem readily available, could one be cut down in
length?

Thanks for your help!
Mike.

Remove _ for valid address wrote in message
...
I'm trying to recondition an Akai GXC760D Hifi cassette deck
(late 70's vintage I believe.)

This is a twin capstan (both engaged at once) design that uses
11.0mm diameter pinch rollers. The diameter is quite critical
as there is only just enough travel on the carriage, the
clearances are tight, and I think the nature of a twin
capstan design makes pinch roller pressure fairly critical.
The common replacement sizes (9.6mm and 13.0mm) do not fit.
I think an acceptable range would probably be 10.5-11.5mm.

The height is 7.9mm and hole diameter 2.5mm, though these
are somewhat negotiable.

I've looked through a variety of usual UK parts sources
(RS CPC/Farnell Grandata CharlesHyde Seme etc)
and I get the feeling nobody stocks other than the two
'standard' sizes.

Anyone know of somewhere that stocks 11.0mm? Anywhere
in the world (though UK would be ideal.)

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.
Or maybe, if a VCR pinch roller of the right diameter existed
(is there a table of VCR model to diameter anywhere??) then
as these seem readily available, could one be cut down in
length?

Thanks for your help!
Mike.


Go to a small industrial rubber products supplier and ask about rubber
cordage, no not S&M.
Local to me
http://www.southamptonuk.co.uk/index.cfm?id=552&cat=346
all 3 Technix, Martins and Portmere are perfectly happy for small sales
enquiries.
Preferably go in when its quiet and stock up with a range of "O" rings and
they may give you a sample length of cordage, otherwise about 2GBP per
metre.
Preferably with a lathe , for centering , drill hole through pieces of the
right length, cut with a sharp knife. One should be good enough

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Remove _ for valid address" wrote in message
...

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.
Or maybe, if a VCR pinch roller of the right diameter existed
(is there a table of VCR model to diameter anywhere??) then
as these seem readily available, could one be cut down in
length?

You could try a razor blade as a cutting tool and very fine cuts.




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(Remove _ for valid address) wrote in
:

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.


The way to reduce the diameter of a rubber cylinder is to chuck in in a
lathe or electric drill, start it turning and bring a block with sandpaper
up to it. You abrade the rubber away, the same way you file your
fingernails.

"Remove _ for valid address" wrote in message
...
I'm trying to recondition an Akai GXC760D Hifi cassette deck
(late 70's vintage I believe.)

This is a twin capstan (both engaged at once) design that uses
11.0mm diameter pinch rollers. The diameter is quite critical
as there is only just enough travel on the carriage, the
clearances are tight, and I think the nature of a twin
capstan design makes pinch roller pressure fairly critical.
The common replacement sizes (9.6mm and 13.0mm) do not fit.
I think an acceptable range would probably be 10.5-11.5mm.

The height is 7.9mm and hole diameter 2.5mm, though these
are somewhat negotiable.

I've looked through a variety of usual UK parts sources
(RS CPC/Farnell Grandata CharlesHyde Seme etc)
and I get the feeling nobody stocks other than the two
'standard' sizes.

Anyone know of somewhere that stocks 11.0mm? Anywhere
in the world (though UK would be ideal.)

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.
Or maybe, if a VCR pinch roller of the right diameter existed
(is there a table of VCR model to diameter anywhere??) then
as these seem readily available, could one be cut down in
length?

Thanks for your help!
Mike.

I've sometimes found that with oddball sizes, they are more a function of
the hub diameter, so if you can get a replacement 9.6mm roller of the
correct width, removing its tyre, and refitting this to the original hub,
will get you a 'new' pinch roller of the correct diameter. The rubber is
quite flexible, and will normally stretch over a slightly larger hub without
too much trouble, helped if necessary, by a little washing up liquid. I've
also performed the same trick where the hub is the same size, by cutting a
short length of heatshrink tubing to fit over the centre part of the hub.
When that is then shrunk on, it will boost the diameter of the hub by up to
a mm, which will do the same to the outer diameter of the tyre when it is
fitted over it. When refitting the tyre, make sure that it has gone into the
hub recess squarely all round. This technique only works of course, for
pinch rollers with a central plastic hub, not those with a moulded-in brass
bush. Bit of a bodge I suppose, but it does work, and is a lot less trouble
than filing and lathing and so on.

Arfa

Remove _ for valid address wrote:

I'm trying to recondition an Akai GXC760D Hifi cassette deck
(late 70's vintage I believe.)

This is a twin capstan (both engaged at once) design that uses
11.0mm diameter pinch rollers. The diameter is quite critical
as there is only just enough travel on the carriage, the
clearances are tight, and I think the nature of a twin
capstan design makes pinch roller pressure fairly critical.
The common replacement sizes (9.6mm and 13.0mm) do not fit.
I think an acceptable range would probably be 10.5-11.5mm.

The height is 7.9mm and hole diameter 2.5mm, though these
are somewhat negotiable.

I've looked through a variety of usual UK parts sources
(RS CPC/Farnell Grandata CharlesHyde Seme etc)
and I get the feeling nobody stocks other than the two
'standard' sizes.

Anyone know of somewhere that stocks 11.0mm? Anywhere
in the world (though UK would be ideal.)

Alternatively, has anyone successfully machined down a larger
size (e.g. 13mm) on a lathe? My gut feeling is that rubber
is unlikely to machine down smoothly, though I've not tried.
Or maybe, if a VCR pinch roller of the right diameter existed
(is there a table of VCR model to diameter anywhere??) then
as these seem readily available, could one be cut down in
length?

Thanks for your help!
Mike.

Its poss to fit a rubber sleeve on a smaller wheel, if that would
otherwise fit.


NT

Just wondering how putting some shrink wrap on the smaller replacement
would go to build up the diam - slip?

David

Remove _ for valid address wrote:

I'm trying to recondition an Akai GXC760D Hifi cassette deck
(late 70's vintage I believe.)

This is a twin capstan (both engaged at once) design that uses
11.0mm diameter pinch rollers. The diameter is quite critical
as there is only just enough travel on the carriage, the
clearances are tight, and I think the nature of a twin
capstan design makes pinch roller pressure fairly critical.
The common replacement sizes (9.6mm and 13.0mm) do not fit.
I think an acceptable range would probably be 10.5-11.5mm.