need advice on rubber isolators

Talon

Member
2014-08-01 11:54 pm
Back in the 20th century I purchased some audio furniture from Bell'Oggetti. All the top shelves on the furniture sat on rubber isolators. They were basically rubber balls about 1.5 inches in diameter, screwed into the furniture on threaded metal studs. They cushioned the glass shelves and absorbed vibrations, and also looked pretty cool.

Over time these isolators have cracked, split open, and started turning to mush. I've emailed Bell'Oggetti to ask where I could get replacements but they've refused to answer. I eventually found a small note on their site that said "don't email looking for replacement parts". SWTH...

Can anyone here recommend where I can get these isolators?

1758301-belloggetti-stands-6-shelf-tower-and-3shelf-tvcenter-channelmedia-stand.jpg
 

Talon

Member
2014-08-01 11:54 pm
I use squash or "racquet" balls under my Linn LP12. They need replacing every couple of years but cost around $10 for 4.

That is probably a good and inexpensive solution for a turntable, but when you have a tv sitting on top of 4 sq ft of art glass, balanced on top of 5 rubber balls, you should want the rubber balls secured to the furniture so that they can't squirrel out from under the glass. The isolators on my furniture are very dense pieces of solid rubber with a threaded rod sticking out of them to make sure they stay in place.
 
Can anyone here recommend where I can get these isolators?

I can't recommend those exact balls... but I can recommend Sorbothane pads like THESE They come in all kinds of shapes and sizes. In your case the hemispheres would make sense. Yes, they are a bit pricey but worth it.

I use the 1/2" thick disks under speakers to isolate the bass from building structures, preventing it from travelling between rooms or apartments. It has very little effect inside the room itself... but it's a real neighbour pleaser.
 
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That is probably a good and inexpensive solution for a turntable, but when you have a tv sitting on top of 4 sq ft of art glass, balanced on top of 5 rubber balls, you should want the rubber balls secured to the furniture so that they can't squirrel out from under the glass. The isolators on my furniture are very dense pieces of solid rubber with a threaded rod sticking out of them to make sure they stay in place.

Then you need some of these industrial machine vibration isolators, also used on Air conditioning.
When bolts exit both sides, they are NOT connected inside, each is attached to a metal disk embedded in the rubber.

taco-de-goma-antivibratorio-bulon-pasante-no-cortado-en-el-interior-5-bolsas-4-tacos-8-tuercas-8-arandelas-D_NQ_NP_703464-MLA28706665310_112018-F.jpg


tacos-goma-antivibratorios-mensulas-aire-acondicionado-split-D_NQ_NP_6326-MLA5051538880_092013-F.jpg


Stay in place heavy duty hemispheres:
antivibratorios-de-goma-barato-1.png


fire up google translate from Spanish to English, these guys explain differentb types and more important, how/which to select them:

Antivibratorio ACOCIL | Metsur

Compresión means compression, easy peasy.

Cizallamiento means shearing pressure , in this case sideways.

kg is that funny weight measure used in ... ummm .... all of the World? ... with just 2 exceptions ;)
 
If the originals are turning to mush, I suspect they are Sorbothane. So flat Sorbothane feet should be stable enough to avoid "squirreling out". Like this?

I have them under speakers up to about 40 pounds (estimated) and no problems in 3 or 4 years. They have a rating sytem in Duros the higher number represents a pad that can take more pressure... but with a bit less "pudge" to absorb heavy vibrations.

It's some weird science. The stuff feels like jello, deforms and returns very slowly, but still supports weight.
 
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Talon

Member
2014-08-01 11:54 pm
I can't recommend those exact balls... but I can recommend Sorbothane pads like THESE They come in all kinds of shapes and sizes. In your case the hemispheres would make sense. Yes, they are a bit pricey but worth it.

Not really. Thats overkill for this.

Then you need some of these industrial machine vibration isolators, also used on Air conditioning.
When bolts exit both sides, they are NOT connected inside, each is attached to a metal disk embedded in the rubber.
...

fire up google translate from Spanish to English, these guys explain differentb types and more important, how/which to select them:

Antivibratorio ACOCIL | Metsur

Literally none of that would work on this.

I'd have though you'd cut them in half first?

Then the hollow part inside the ball would collapse when the internal pressure was gone.

If the originals are turning to mush, I suspect they are Sorbothane. So flat Sorbothane feet should be stable enough to avoid "squirreling out". Like this? Sorbothane vibration isolating circular pad, 0510435, 0510436, 05
Otherwise, anti vibration mounts from ebay. [[/url]

These aren't sorbothane. They're 25 years old, and just suffering from age and environment.

Guys, while I appreciate the answers and advice, you're over-analyzing this. I'm not looking for a vibration-free lab environment to do interferometer research - I just want to put some replacement hard rubber spheres in between the furniture and the shelf glass - so I'm really not looking for anything that absorbs vibration. I really don't want to experiment around and look for anything other than what the furniture came with. Its just a very hard, rubber ball - and I have no idea what the durometer rating is - with a threaded metal stud sticking out of it. The ball screws into a socket on top of the furniture, the glass sits on top. It absorbs the weight of the tv or whatever sits on the glass, it deforms slightly, it holds the glass firmly in place.

The closest thing I can find it is a rubber knob drawer pull:

thermoplastic-ball-knobs-8569-p[ekm]180x180[ekm].jpg


Picture that but with a half inch long thread sticking out. The stud is actually the end of a flat-headed screw encased in the rubber sphere. BellO'ghetti didn't invent these, they bought them from a furniture parts supplier. There has to be a source out in the wild somewhere.
 
Picture that but with a half inch long thread sticking out. The stud is actually the end of a flat-headed screw encased in the rubber sphere. BellO'ghetti didn't invent these, they bought them from a furniture parts supplier. There has to be a source out in the wild somewhere.
Well, good luck with that. Otherwise you may have to compromise. Cone Rubber Bump Stop - Male Thread (WDS 715) | WDS
 
Guys, while I appreciate the answers and advice, you're over-analyzing this. I'm not looking for a vibration-free lab environment to do interferometer research - I just want to put some replacement hard rubber spheres in between the furniture and the shelf glass - so I'm really not looking for anything that absorbs vibration. I really don't want to experiment around and look for anything other than what the furniture came with.
Which makes me think you posted in the wrong forum, perhaps "parts" or "construction tips"?
 
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Guys, while I appreciate the answers and advice, you're over-analyzing this. I'm not looking for a vibration-free lab environment to do interferometer research - I just want to put some replacement hard rubber spheres in between the furniture and the shelf glass - so I'm really not looking for anything that absorbs vibration. I really don't want to experiment around and look for anything other than what the furniture came with. Its just a very hard, rubber ball - and I have no idea what the durometer rating is - with a threaded metal stud sticking out of it. The ball screws into a socket on top of the furniture, the glass sits on top. It absorbs the weight of the tv or whatever sits on the glass, it deforms slightly, it holds the glass firmly in place.

Hmmm ... okay... you initially said "rubber isolators" so that's what I was suggesting. If they don't have to be spherical ... hemisphere, blocks, cylinders, etc... just grab some self stick silicone rubber pads and have it done.

Depending on the age of your stand, you might not be able to find exact replacements.
 

Adhoc1

Member
2012-04-17 12:59 pm
If you don't care about vibration isolation and just want a piece of rubber with a thread to screw into the legs, -check out post #10 and the link in it.

(Those in the link work quite well but to be able to isolate well down to about 20 Hz, each rubber "puck" needs to have a substantial mass on it, so the rubber piece gets a deflection of 6-7 mm /1/4"). = Probably not at all possible with usual HiFi gear , TVs etc on the glass shelf. I believe what you did have was something that looked cool and prevented rattling noise but was more or less snake oil considering vibration isolation.)
 
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Talon

Member
2014-08-01 11:54 pm
Which makes me think you posted in the wrong forum, perhaps "parts" or "construction tips"?


Perhaps. There wasn't any forum that dealt with audio furniture, and the ones you suggested seemed to deal with speakers. I posted here because I thought that audio furniture was a significant part of acoustics and someone here might have some experience building said furniture.

Well, buy some threaded rod and you are done... I suppose those knobs are of suitable size?

I wouldn't know. I just posted those as an example.

Hmmm ... okay... you initially said "rubber isolators" so that's what I was suggesting. If they don't have to be spherical ... hemisphere, blocks, cylinders, etc... just grab some self stick silicone rubber pads and have it done.

I said "isolators" because that seemed to be the proper word for the type of part I was looking for.
They DO have to be spherical, because I'm basically trying to restore this audio furniture to what it was originally.

Depending on the age of your stand, you might not be able to find exact replacements.

Thats what I'm afraid will be the case.

You could always pay a model maker to mold you some...

I did see some that were a different style at McMaster Carr, had a stepped, wedding cake, Art Deco style.

Thanks, but I'd like to stick to what these originally came with.
 

Talon

Member
2014-08-01 11:54 pm
I can find any number of "solutions" on my own for stable, vibration-free shelf mounting. What I'm trying to do is restore this furniture. I'd like to put it back into "like new" shape.

Since the wood is unmarred and the finish is perfect and none of the glass is chipped or scratched, all I need to make these towers like new are these little rubber balls with threaded studs sticking out of them.