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TIP: Silicone rubber flat drive bands

Discussion in 'Electronic Repair' started by N_Cook, Oct 22, 2013.

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  1. N_Cook

    N_Cook Guest

    Came across a useful resource, extending the silicone fold "flat"
    collapsible funnels, source of preformed rubber. Similar items , going
    up in size available in camping shops XMUG and XBOWL badged "Sea to
    Summit" Perth Australia
    The mug one 75mm to 105mm diameter, 7 bands available up to 8mm wide.
    At 1.8mm thick need splitting to .9mm so one good face and one usable in
    many circumstances. So 14 bands or 28 if split widthwise.
    4 of the 7 are regular flat , 3 are on the slope but uually usable I've
    found. Not had any such useages return to me so I assume they have not
    broken in use
    The bowls I saw have a reduced range of sizes 3 up to 150mm and 5 up to
    220mm diameter
  2. N_Cook

    N_Cook Guest

    Don't expect to have a clean external edge to the largest band. Someone
    knows how to bond silicone rubber to plastic. Applying heat and/or
    peeling action will only result in ripping the silicone. I would like to
    know what the chemical/process that does that. At least the cup-size
    marks are easy to grind off the internal surface
  3. Charlie+

    Charlie+ Guest

    Nice one! Cost of cup seems to range approx £9 -12 in UK
  4. N_Cook

    N_Cook Guest

    The funnels are much cheaper and fuller range, but smaller maximum
    diameter. The bowls are about twice the price and not much silicone bandery
    At the moment sousing the rim band in 3 different solventy type
    chemicals trying to find something that will break the bond
  5. N_Cook

    N_Cook Guest

    Because originals are a waste of time. I've never seen a supplier that
    states their bands are newly made. They turn up wiht the telltale brown
    staining inside the polythene bag.
    I've never got in the routine of taking pics on disassembling stuff,
    just marking mating pieces. I don't want a pile of bits hanging around
    for the vagueries of the postal system and then high probability of the
    wrong band arriving as usually no precise dimensions from the gooey mess
    left behind. Fresh in memory the half hour to cut and try a band or 2 or
    3 before reassembling. Speed/function tests can wait until convenient to
    set up for it
    What do you do when your supplier does not have the size of band that
    you need?

  6. I always used to try to stock most sizes I was likely to see, and restock
    when I would put in an order with our primary supplier of such, MCM
    Electronics (I believe "Element 14" in the UK?).

    That was in the days when belts were so cheap it made sense to do so, plus I
    was working on lots of cassette decks, CD players, VCR's and the like in
    those days. It was like stocking a range of capacitors, transistors, etc.
    Common practice.

    Times have changed, belt jobs are nowhere near as common, suppliers are
    fewer, and prices on those common belt sizes much higher. I can no longer
    buy belts just to have them sitting unused.

    I still have lots of belts in stock, but special orders are becoming more
    frequent these days, and some special belt sizes have to be substituted with
    less than desirable replacements.

    For example, some belts are VERY special insofar as dimensions. For example
    the carousel belts for Sony CDP-CX355, 455 etc, where the circuit cannot
    properly count or position the discs with a sub belt - at least I have not
    found an acceptable sub. When Sony discontinues those belts, I'm going to
    have a problem. Luckily that basic mech is still in production AFAIK - at
    least you can still buy new similar models. Should be OK for the next few

    The approximately 2.8 x .05 inch belts (discontinued) which along with the
    capstan belts dying in droves on their dual-well cassette dicks, are another
    matter. The only sub I can find is a little too thin, and much too tight.

    Mark Z.
  7. N_Cook

    N_Cook Guest

    Are you talking toothed/timing belts for the Sonys?
    As long as you allow for the more stretchiness of silicone rubber, ie
    can have a belt that is thicker or wider or both then no problem. I did
    find once I had to grind back a fixing post or something that was
    fouling on a thicker silicone belt. I assume there must be long term
    degradation problems with silicone rubber but not seen so far.
    I suspect the tiniest .5x.5mm or so belts as on the rotation sensor/
    milometer counter belts will be the first to fail. I suspect silicone is
    more prone to rip at any imperfection , more so than neoprene
  8. N_Cook

    N_Cook Guest

    Tried petrol, nail varnish remover and methyl chloride paint stripper
    over a day, on different parts of the rim. With a plectrum , could
    separate the bit soused in paint stripper. Came away clean enough but
    quite a bit of shear force required, perhaps longer or kept at an
    elevated temp
  9. N_Cook

    N_Cook Guest

    "I can assure you that they are absolutely new. "
    How do you know they have not removed them from original bags and
    placed them in new bags?
    Unless the bands are glooppy or lack restitution how would you know they
    are NOS? servicable for only a few years of end of life.
    Unless your supply company is supporting a currently available product
    that uses baluster pulleys, what is the commercial motive?
    If they are a genuine specialist supplier of new bands I would expect
    them to go into some detail of how they are made and how they are
    tested/QC'd etc and be an offshoot of the likes of Comrie or Martins or
    Portmere , say, rubber companies

  10. No, not toothed. As best I recall, near 4 point something inch
    circumference, maybe around .06" thickness. The mech uses two of them at the
    rear area - one to rotate the carousel, the other to clamp the disc. The
    clamper belt is somewhat forgiving but not the carousel belt.

    The part number is 4-225-876-01 as shown on page 57 of the CDP-CX455 service

  11. N_Cook

    N_Cook Guest

    Recently I was surprised to see a toothed timing belt driving the jocky
    wheel assembly for Play/REW/FF of the spool drive on a Sony EV-S700
    video /PCM audio recorder
  12. N_Cook

    N_Cook Guest

    Take as a for instance as the first and only one that came up with my
    search terms
    nowhere does it state they are new flat belts so I would not purchase
    from there.
    I would be a lot more confident that they were newly made if their range
    of belts were listed as 20,25,30,35,40,45 ... mm diameter and not linked
    to ancient makes and models with odd dimensions and then a separate
    table of original band sizes and you could make your decision whether to
    go over or under for replacements
  13. Have you got one of those? That model was a lot more accurate than the
    1939 version and is much sought after.
  14. N_Cook

    N_Cook Guest

    They don't make things like they used to. My coil winding machine, made
    in about 1926, I resucitated from being 20 years in a leaking garden
    shed. I've just used my , made in 1918 in Conneticut, pair of parallel
    jaw pliers, if I last out they will still be being used in 2018
  15. Chris Jones

    Chris Jones Guest

    Would you care to let us know the name and/or contact details for these
    suppliers? Fair enough if you don't want to, but I have a tape deck and
    a record player both in need of new belts, and I don't live near enough
    to you for it to make sense getting you to fix it.

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