Cleaning a Pinch Wheel

[Mike Brett]

Hi all
Having trouble with my newly acquired J.V.C. Cassette Recorder. I did a belt replacement when I first got the machine about two months ago and at the same time I cleaned the heads with 99% alcohol. At the time I must have got some of this alcohol on the pinch wheel as although it worked fine with its new belt, now two months later it plays the tape at a very slow speed. The pinch wheel seems to have gone very hard and appears to have lost a lot of its grip.
I have heard there is a liquid sold for rejuvenating these pinch wheels but have not been able to locate any as yet. Has anybody come up with a method to refresh the rubber on these wheels as replacement seems a bit impossible through lack of obtainable spares.
Cheers Mike

[Ekcoman]

Solvent Paint Thinner on a cotton bud in minute quantity? but deadly stuff if it gets on any plastic. Trouble is, if rubber really hard, it may only give temporary answer.

['LIVEWIRE?']

Over many years working as a service engineer, I used to clean pinchrollers in car cassette players with methylated spirits ( The blue kind). I've also used IPA and proprietry brands of cleaning fluid and never had, AFAIK, any long term problems, as a result of using any of the above. Never tried paint thinner, though! As to the 'rubber rejuvenator' liquid, I, too, have heard of it, but never used it.

[Radio_Dave]

People who raced Scalextic cars used to wipe lighter fluid on the back wheels to give them extra grip. It was only a temporary effect though and eventually ruined the tyres.

What size is it? Would one of the generic ones from CPC do the job? http://cpc.farnell.com/jsp/search/br...equestid=46345 (don't forget internet orders are post free)

David

[sp10mk11]

CPC sell a suitable one part number;

AVAS2 it is a standard 13mm size one except the shaft hole is 2.5mm instead of the more common 2mm shaft size

Is this an old Silver fronted model I should have asked first as these used the pinch roller described later 80s models I think used the smaller 2mm shaft hole type

Gary

[DOFFERY]

Mike,
The solvent you mentioned is Electrolube RRR, I regret I didn't have much success with it. Regarding your cassette pinch wheel there were many varieties, not only did the shaft dia. vary but the shape itself. A pic of the shape plus the shaft dia if known would be useful to ascertain the right one.

Colin.

[Peter.N.]

If the rubber has gone terminally hard, rubbing it with some very fine abrasive paper will improve the grip for a while.

Peter

[Mike Brett]

Many thanks for all your replies. My JVC is the black fronted model, CD-1635 mark 2. My pinch wheel is 13 mm in diameter , difficult to measure the depth without taking it out but it is about 7 mm. Again the top of the shaft measures 2.5 mm but without dismantling it I can only guess that this is the measurement all the way down the spindle.I should not have said it was very hard as on pressing my fingernail into it it does have a lot of resilience to it.The problem is on playback it slows down and even stops on occasions,but the spindle on the flywheel keeps turning so the problem must be with the pinch wheel.I will try a bit of fine abrasive paper and see if that improves the situation.
Mike

[Mike Brett]

Well I tried a small emery board out of the wife's manicure set and that worked a treat, not sure how long it will last but it is playing again now and sounds fine.In future I will treat the pinch wheels with more respect and keep the alcohol away from them.
Many thanks Mike

[Ekcoman]

Just a thought Mike but their are rare occasions when the drive spindle is off at a slight angle to the pinch wheel so not getting the same pressure across all of the tape as it passes through.

[sp10mk11]

This is one of the lovely portable hi-fi machines! I would not hesitate to change the pinch roller, a high quality machine like this needs doing properly not bodging (no offence)...........go on spend the time and a bit of money

All the best
Gary

[Mike Brett]

Interesting, if one did find that the drive spindle was indeed not at a true right angle to the pinch wheel is this fixable, is there an adjustment for such an occurrence.
Mike

[ricard]

There is a spray from Kontakt-Chemie called Gummi-Reiniger (aka Kontakt GR) which does a very good job of cleaning and to some extent restoring rubber surfaces. I never spray it on directly though, but spray it on a Q-tip or clean rag, and then use that to clean the rubber.

Even if the alcohol has somehow damaged the surface, if it is only a little I doubt it would have gone very deep, so just removing an alleged hardened surface with the emery board might very well be a permanent solution. I always follow up any abrasive cleaning methods with Kontakt GR in order to get rid of any rubber grit on the surface.

[sp10mk11]

Surely if the capstan shaft is off true then the tapes would be get damaged as they would ride up and down or where ever, and the same for the pinch roller not sitting square.

One way to see if it is the roller losing grip is when it slows down apply a little pressure to the roller housing so it pushes harder on the tape, if it speeds up then that's a good indication that after all these years the rubber has changed and has lost its grip, in exteme cases the roller can go a sort of barrel shape

I am willing to accept that not all rollers go this way as I have two Sony machines that the pinch rollers are perfect in and they are 40 years old, but in my experience this a rarity.

I also would be loathe to put anything on a roller that doesn't evaporate, it could coat the tapes aswell.

Gary

[saxmaniac]

The cassette deck is one used in many other units as it was sold to other manufacturers. You may be able to get a cheap unit complete for spares using this deck. Coomber early equipment used them and they go for not much money on ebay. Others here may list other sources for the deck, I presume Ferguson used them as well. This deck is a very good unit and will sound great when working. give the switches a really good clean as well

[brunel]

Have a search for PLATEN CLENE.

This stuff: http://www.amazon.co.uk/AF-Internati.../dp/B0012IKSHO

[John_BS]

Thanks for the link to PLATEN CLENE. I searched for the COSHH data-sheet, and discovered that it's identical to Electrolube RRR. The latter appears a tad more expensive, but the can is 250ml as opposed to 100ml for the PLATEN CLENE.

John