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    rubber isolation washers

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    MontanaWay

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    rubber isolation washers

    Post by MontanaWay on Fri Mar 28, 2014 1:45 pm

    I'm having a hard time finding simple rubber isolation washers used in mounting transformers on chassis.
    The size I'm looking for is about 0.5" outer dia, about 0.185" hole dia and about 0.1" thick. Can be a little thicker and the outer dia can also be little larger, either in black or brown.
    Can anybody please point me to a supplier, thanks.

    Bob Latino
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    Re: rubber isolation washers

    Post by Bob Latino on Fri Mar 28, 2014 2:51 pm

    Go to any plumbing supply house or a Home Depot, Lowe's etc. and ask for "00 flat plumbing washers"  ..

    Bob

    MontanaWay

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    Re: rubber isolation washers

    Post by MontanaWay on Fri Mar 28, 2014 3:18 pm

    thank you Bob!....much appreciate it!

    Captain Coconut

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    Re: rubber isolation washers

    Post by Captain Coconut on Fri Mar 28, 2014 3:21 pm

    I was thinking of getting some too. Now I know where to find them.  cheers

    sKiZo

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    Re: rubber isolation washers

    Post by sKiZo on Fri Mar 28, 2014 3:46 pm

    Another option is to oversize the mounting holes a bit and use grommets.

    I went with an oversized hole (10mm or thereabouts if I remember right) , an 00 washer between the transformer and chassis plate, and a 1/4" beveled washer underneath, bevel side in, with a flat meta washer between that and the nut. When compressed the two rubber washers actually touch each other, centering the bolt in the hole and preventing any chance of metal to metal contact.



    Also available at the local hardware in the plumbing section.

    Bit overkill, but I also added a thin nylon washer at the head end of each screw AND did a layer of heat shrink on the threads inside the iron. Just razor it off a bit proud of the chassis plate so it doesn't get in the way when you tighten the nuts.

    And with all that, I still get a bit of transformer noise, but I've convinced myself it would have been worse without the extra steps. Yup ... that's my story, and I'm stickin' with it!  geek

    MontanaWay

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    Re: rubber isolation washers

    Post by MontanaWay on Fri Mar 28, 2014 5:04 pm

    if only we could levitate transformers....hhhmmmmm...super conductor??  Shocked 

    MontanaWay

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    Re: rubber isolation washers

    Post by MontanaWay on Fri Mar 28, 2014 5:06 pm

    sKiZo wrote:Another option is to oversize the mounting holes a bit and use grommets.

    I went with an oversized hole (10mm or thereabouts if I remember right) , an 00 washer between the transformer and chassis plate, and a 1/4" beveled washer underneath, bevel side in, with a flat meta washer between that and the nut. When compressed the two rubber washers actually touch each other, centering the bolt in the hole and preventing any chance of metal to metal contact.



    Also available at the local hardware in the plumbing section.

    Bit overkill, but I also added a thin nylon washer at the head end of each screw AND did a layer of heat shrink on the threads inside the iron. Just razor it off a bit proud of the chassis plate so it doesn't get in the way when you tighten the nuts.

    And with all that, I still get a bit of transformer noise, but I've convinced myself it would have been worse without the extra steps. Yup ... that's my story, and I'm stickin' with it!  geek

    I like that 'squishing' effect, might get some and try it out!

    corndog71

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    Re: rubber isolation washers

    Post by corndog71 on Fri Mar 28, 2014 5:09 pm

    MontanaWay wrote:if only we could levitate transformers....hhhmmmmm...super conductor??  Shocked 

    Or just levitate the whole amp.  Of course, it's gonna cost ya.


    https://www.gcaudio.com/cgi-bin/store/showProduct.cgi?id=247

    MontanaWay

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    Re: rubber isolation washers

    Post by MontanaWay on Fri Mar 28, 2014 5:28 pm

    corndog71 wrote:
    MontanaWay wrote:if only we could levitate transformers....hhhmmmmm...super conductor??  Shocked 

    Or just levitate the whole amp.  Of course, it's gonna cost ya.


    https://www.gcaudio.com/cgi-bin/store/showProduct.cgi?id=247

    damn!...and I thought I was joking..........  silent 

    sKiZo

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    Re: rubber isolation washers

    Post by sKiZo on Fri Mar 28, 2014 5:46 pm

    My favorite part from the web page ...

    I am strongly attracted to these magnetic feet ...

    What ... too much iron in the diet?  geek 

    Maybe more practical to do an audiophile version of the nursery crib mobile ... only with 20 pound transformers ... might want to use some stronger string, eh.



    deepee99

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    Re: rubber isolation washers

    Post by deepee99 on Sun Mar 30, 2014 7:10 pm

    Spade bit, Sawzall and an old inner-tube are the low-budget solutions.
    I've resolved the transformer hum issue rather more elegantly. A solar-powered helicopter drone hovers above the roof-line, with the xformers chained to it and the amps by wires of unobtanium. Works beautifully when the sun is out.

    Captain Coconut

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    Re: rubber isolation washers

    Post by Captain Coconut on Sun Mar 30, 2014 7:14 pm

    I used some grommets I had kicking around. There's more of a buzz than a hum now.

    deepee99

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    Re: rubber isolation washers

    Post by deepee99 on Sun Mar 30, 2014 7:16 pm

    Captain Coconut wrote:I used some grommets I had kicking around. There's more of a buzz than a hum now.

    The buzz might not be emanating from the electronics.

    Captain Coconut

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    Re: rubber isolation washers

    Post by Captain Coconut on Sun Mar 30, 2014 7:31 pm

    Oh oh!

    Bob Latino
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    Re: rubber isolation washers

    Post by Bob Latino on Sun Mar 30, 2014 8:19 pm

    Just one other note ... Those 00 flat plumbing washers are made of "neoprene" which is a synthetic rubber and is much more heat resistant than regular rubber. Neoprene will take up to 200 degrees Fahrenheit without degradation of its physical characteristics. The power transformer can get up to 120+ degrees. The washers are unaffected by the heat from the power transformer.

    Bob

    MontanaWay

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    Re: rubber isolation washers

    Post by MontanaWay on Sun Mar 30, 2014 8:40 pm

    Bob Latino wrote:Just one other note ... Those 00 flat plumbing washers are made of "neoprene" which is a synthetic rubber and is much more heat resistant than regular rubber. Neoprene will take up to 200 degrees Fahrenheit without degradation of its physical characteristics. The power transformer can get up to 120+ degrees. The washers are unaffected by the heat from the power transformer.

    Bob

    I guess I could always cut up my old neoprene diving suit....... Shocked 

    Luddite

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    Re: rubber isolation washers

    Post by Luddite on Mon Mar 31, 2014 10:13 am

    MontanaWay wrote:
    Bob Latino wrote:Just one other note ... Those 00 flat plumbing washers are made of "neoprene" which is a synthetic rubber and is much more heat resistant than regular rubber. Neoprene will take up to 200 degrees Fahrenheit without degradation of its physical characteristics. The power transformer can get up to 120+ degrees. The washers are unaffected by the heat from the power transformer.

    Bob

    I guess I could always cut up my old neoprene diving suit....... Shocked 

    ...or you could try these  http://www.dynakitparts.com/dynakit-products/hardware/POWER-TRANSFORMER-ISOLATION-MOUNTS

    tubes4hifi
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    Re: rubber isolation washers

    Post by tubes4hifi on Mon Mar 31, 2014 12:13 pm

    aren't you guys still having transformer contact the chassis when using these thin rubber washers?
    I use 1/8" sorbothane under the transformers, and then use the neoprene washers.
    Sometimes easier to find (or maybe the same) are fiber (fibre) washers, made of a semi-hard material, like dense cardboard,
    usually easy to find in any hardware store. Lots of sorbothane on ebay.
    Cut one of these in 4 pieces for your transformers
    http://www.ebay.com/itm/Sorbothane-SHEET-6X6x1-8IN-VIBRATION-ISOLATION-RUBBER-PAD-150MM-SQUAREx3-2-70D-/370764126470?pt=LH_DefaultDomain_0&hash=item5653439906

    MontanaWay

    Posts : 767
    Join date : 2014-02-06
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    Re: rubber isolation washers

    Post by MontanaWay on Mon Mar 31, 2014 12:19 pm

    tubes4hifi wrote:aren't you guys still having transformer contact the chassis when using these thin rubber washers?
    I use 1/8" sorbothane under the transformers, and then use the neoprene washers.
    Sometimes easier to find (or maybe the same) are fiber (fibre) washers, made of a semi-hard material, like dense cardboard,
    usually easy to find in any hardware store.   Lots of sorbothane on ebay.
    Cut one of these in 4 pieces for your transformers    
    http://www.ebay.com/itm/Sorbothane-SHEET-6X6x1-8IN-VIBRATION-ISOLATION-RUBBER-PAD-150MM-SQUAREx3-2-70D-/370764126470?pt=LH_DefaultDomain_0&hash=item5653439906

    if as a previous post suggested, you use a beveled washer on the bottom/inside the chassis, flat washer on top of the chassis, that pretty much isolates the transformer from the chassis. Once you tighten the nut, the beveled washer gets squeezed up through the chassis hole and makes contact with the top washer. I would also use a washer under the beveled washer so that the nut does not damage it.

    deepee99

    Posts : 1260
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    Re: rubber isolation washers

    Post by deepee99 on Mon Mar 31, 2014 12:22 pm

    MontanaWay wrote:
    tubes4hifi wrote:aren't you guys still having transformer contact the chassis when using these thin rubber washers?
    I use 1/8" sorbothane under the transformers, and then use the neoprene washers.
    Sometimes easier to find (or maybe the same) are fiber (fibre) washers, made of a semi-hard material, like dense cardboard,
    usually easy to find in any hardware store.   Lots of sorbothane on ebay.
    Cut one of these in 4 pieces for your transformers    
    http://www.ebay.com/itm/Sorbothane-SHEET-6X6x1-8IN-VIBRATION-ISOLATION-RUBBER-PAD-150MM-SQUAREx3-2-70D-/370764126470?pt=LH_DefaultDomain_0&hash=item5653439906

    if as a previous post suggested, you use a beveled washer on the bottom/inside the chassis, flat washer on top of the chassis, that pretty much isolates the transformer from the chassis. Once you tighten the nut, the beveled washer gets squeezed up through the chassis hole and makes contact with the top washer. I would also use a washer under the beveled washer so that the nut does not damage it.
    Just turn the sucker up loud enough and the music will drown out the mechanical hum. Hmmmmm

    Tube Nube

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    Re: rubber isolation washers

    Post by Tube Nube on Mon Mar 31, 2014 2:38 pm

    Should be able to diy those magnetic levitators with some pvc tubing and strong magnets.

    Captain Coconut

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    Re: rubber isolation washers

    Post by Captain Coconut on Mon Mar 31, 2014 9:30 pm

    Captain Coconut wrote:I used some grommets I had kicking around. There's more of a buzz than a hum now.

    Just for the record, the transformer is almost silent now; you have to have your ear within 4" and the hum is hardly discernible. This is a bucker I'm talking about. It's mounted to the top of my pony panel with grommets - screws not in contact with any metal.

    sKiZo

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    Re: rubber isolation washers

    Post by sKiZo on Tue Apr 01, 2014 2:19 am

    Bit of a derail, but how's that muther bucker working out for you? Mine's rated at 6a, plugging right along and barely gets warm. For mostly salvage odds and ends, a real nice addition to the system.



    As you can see, I just hard riveted mine together. Perfectly quiet.

    Captain Coconut

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    Re: rubber isolation washers

    Post by Captain Coconut on Tue Apr 01, 2014 8:07 am

    It's working great! I picked up a Hammond 167U5 at their warehouse for less than $30. It's rated for 15A so I run everything off it. It gets ever so slightly warm to the touch and is now very quiet.

    I had 124 VAC wall voltage yesterday and the bucker knocked it down to 118.5VAC.  Very Happy 

    Luddite

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    Re: rubber isolation washers

    Post by Luddite on Tue Apr 01, 2014 6:11 pm

    Just for the record, I've found that audible noise from power transformers was most often conducted through the chassis to the shelf. The shelf acts like a sound board and increases the audibility of the noise. Vibrapods or some other type of Sorbothene feet should resolve this problem. If you want to experiment before buying these, get several (cheap) art gum erasers from a school or art supply store and rest the chassis on three or four of these. Heck, you might even decide to just keep the erasers and spend your serious money elsewhere.

    Best Regards,
    Charlie

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