Vibration Air & Roller Bearings - Thanks to Barry & Warren

[rando]

Quote

What I am looking for is some cheap, easy to obtain smooth cups...

 

Try the petite section and ask for AAA cups.  The radius should be near optimal.

[jabbr]

3 minutes ago, Ralf11 said:

There are dat a sheets for Sorbothane posted somewhere on the internet

 

 

What I am looking for is some cheap, easy to obtain smooth cups...

 

Try something like: http://www.ebay.com/itm/Set-of-4-Dollhouse-Miniature-Fancy-White-Glazed-Porcelain-Dinner-Plates-SPL05-/371818369682?hash=item56921a1292:g:4J4AAOSwImRYV40A

 

as a start, if you hear a difference you may wish to investigate the more "official" solutions...

[Ralf11]

I've found some of those but thought they were too flat.  Also, do you think they have adequate surface  smoothness?

[jabbr]

2 minutes ago, Ralf11 said:

I've found some of those but thought they were too flat.  Also, do you think they have adequate surface  smoothness?

 

Flat is fine -- the edges prevent the balls from rolling off -- you may find that the balls go to the edge which will lose effectiveness. Smoothness is ok -- better than nothing. 

[Ralf11]

Thx - I'll try them out despite the possibility of Type II errors.

 

I just realized I'll never be able to find the ball bearings I have...

 

Amazon also has smooth polish finish 1/2" Inch Chrome Steel Bearing Balls - any thoughts, pro or con, on these?

[Audiophile Neuroscience]

58 minutes ago, JohnSwenson said:

The level 2 system consists of two "blocks" per support location. Each block has a highly polished spherical depression. You put a ball in the depression, and put another block upside down on top. The level 2 ones take a 3/8" ball. The top one just flops around on top of the ball until you put something on top of a set of three. The top block then "levels out" on the under side surface of the supported device. As the blocks move relative to each other the ball is rolling between the the two curved surfaces.

 

This particular system has a very small amount of play, so as you turn knobs, push buttons etc, it can't move very far which doesn't feel too wobbly. The isolation is still effective because the actual displacement for real seismic noise is VERY small.

 

I prefer to use them with a flat plate on the top, this halves the resonant frequency, which is good for isolation, but it allows for more motion when your hand is moving things.

 

A set of level 2 supports contains 6 blocks, using two for each support location (assumed to be a triangle), with a single ball for each set of two.

 

When I got mine they did not come with balls, I ordered some from McMaster Carr. I got both 1/4" and 3/8" chrome steel balls, for the two block approach it has to be the 3/8, for the flat top approach either works but I preferred the 1/4".

 

When going with the flat top you only need one block per location so you can do two platforms for the price of one!

 

Thank you John for this explanation.

 

In effect the top block forms a support platform of sorts for the component.Not being a flat surface I would anticipate that it also restricts roller ball motion, less than ideal for achieving the least amount of damping of isolator motion to achieve the steepest rollof above resonance.

 

OTOH one cup (and ball) is required beneath the component for practical purposes, not the least preventing the gear from rolling right off the shelf or knock into something else, defeating isolation.

 

I must say, for me, Barry's approach is elegantly simple, many great things are. I have now used multiple air and roller bearings under reasonably heavy gear as well as very lightweight eg LPS1. My interconnects (gryphon guideline) are stiff but I have been able to mange to maintain the 'wobble factor'. I dont find the springiness of the inner tubes to be a stability concern nor the roller bearings.

 

Barry's idea regarding the support platform is to achieve maximum rigidity with *minimum mass*, and thus the use of a relatively light weight acoustically dead tile, rather than heavier metal platform.

 

It would be interesting to see how these different approaches measure.

 

Cheers

David

[Audiophile Neuroscience]

43 minutes ago, rando said:

 

Try the petite section and ask for AAA cups.  The radius should be near optimal.

 

More wearable audio? Make sure you get a matching coloration with the bass vests

[rando]

@Ralf11  Puerile humor aside, I have one very simple to source idea that should prove the concept with little waste of time or materials.  

 

I have collected a ton of promotional lip balms that were handed out.  The inside of the caps lack any release marks and are extremely smooth.  Gist of is you cut it down and toss a small bearing in each one.  The inside is a flat surface and you will need a level one to set them on (Tip: Bearings should protrude enough you can center them using a needle nose pliers or similar once weighted.)  Using either a light shelf or the bottom of a lighter device set it directly onto the three bearings

 

This cap is 9mm tall and should hold enough structural resilience after trimmed to size for your purpose.  Excuse my sub-par lighting attempt.  The bottom surface is very smooth. 

 

 

[Ralf11]

Thx - I am a bit confused.  The typical sticks seem too small - I can just get my little finger into one...

[rando]

I measure a 1/2" diameter which should allow for a 1/4" bearing to have more than enough play.  What this satisfies over the dollhouse platter set is a surface that is actually smooth and has no chance of the bearing running.  Remember the only movement we are concerned with is too small to see and the only concern is too much freedom of movement when bumped.  Much like a lever the advantage here is so strong you don't need to lift much or very efficiently to prove how well it works over nothing.  So your control is setting the small device directly onto the surface the cup and ball rested on.

 

Go ahead and laugh at me for simplifying this so much.  I offered it in good humor half expecting an appalling response.  

[Ralf11]

No, not laughing and may try it.  I wonder about the flexibility it may have tho.

[Ralf11]

related thread:

 

 

 

[JohnSwenson]

7 minutes ago, Ralf11 said:

No, not laughing and may try it.  I wonder about the flexibility it may have tho.

When I was first playing with this I found some drawer pulls at a local hardware store that were round with concave surface. I screwed these onto a block of wood. Cost less than a dollar a piece.

 

A quick google search for concave drawer pull  shows a whole bunch available.

 

John S.

[rando]

The hard level surface the caps are resting on should give it a lot of stiffness since they're so thin.  On anything but a molecular level, and with the downward force split three ways, I don't expect a few pounds will result in so much deformation it will fail to work.

 

Obviously I'm just guessing on all of this.  I didn't have to get quite this resourceful based on the items I have on hand to recreate BD's double bearing solution.  

[Ralf11]

Thx Rando & John - I should have thought of concave drawer pulls...

[jabbr]

I tried concave lenses -- didn't like the SQ -- damped them with some putty/goop but this soon started to slide around ... then I got the alu bowls (per BD)

[rando]

Finally hewed my way through the entirety of the old thread.  Talk about ending on a sour note.  Can anyone explain why Barry chose to leave the forum?  

[Ralf11]

35 minutes ago, jabbr said:

I tried concave lenses -- didn't like the SQ -- damped them with some putty/goop but this soon started to slide around ... then I got the alu bowls (per BD)

 

lenses = glass, right?

[One and a half]

39 minutes ago, rando said:

Finally hewed my way through the entirety of the old thread.  Talk about ending on a sour note.  Can anyone explain why Barry chose to leave the forum?  

Best to ask @Yashn.

[rando]

I don't feel that will be any more necessary than teaching you how to mention someone correctly.  

[Audiophile Neuroscience]

4 hours ago, rando said:

Can anyone explain why Barry chose to leave the forum?  

 

I have not read the original thread yet but perused the last several pages. I note that 'words' were exchanged with a couple of the participants. Notably, I saw hints  that Jud and SandyK were aware of Barry's leaving with Jud saying he could speculate why but I guess wisely, did not.

 

I have had the good fortune to 'meet' a number of wonderful people through CA.Two of them I have remained in contact with before and after I left CA a couple of years back. SandyK who I have met in person, and Barry with whom I have periodically corresponded . Barry recently viewed the eclipse and SandyK (Alex K) will hopefully get reconnected to the internet tomorrow ( i got an sms from him Tuesday)

 

I will not presume to speak for Barry but will simply say, IMHO, his leaving was a great loss to the audio community at CA. He has been and continues to be extraordinarily helpful and kind to me when I pester him about all things audio.I have in fact set up my entire listening room based on Barry's recommendations which nearly always accords with my own research, my limited understanding of physics (first year University level) and my somewhat better understanding of perceptual processes and the human mind.His recommendations just work, in my experience improving sound quality.

 

I am guessing Jud is watching this thread so just curious, why did you suggest I kick this thread off knowing vibration isolation had been previously discussed?

 

David

 

 

 

 

 

[AnotherSpin]

7 hours ago, Ralf11 said:

Thx Rando & John - I should have thought of concave drawer pulls...

 

Different materials (or ready baby toys, drawer pulls, etc.) were discussed in old thread. With many pictures as well. After some trials I found out only aluminum would be used effectively. Unless we do speak about some exotic pricey metals from less often visited parts of periodic table. And, not only aluminum, but very high grade aluminum, air industry quality. More convenient soft grades alu cups will not work for long because they will get dented. Second, correct proportions between roller bearings diameter and cup concave shape is critical. Again, not just steel, but better quality alloys. I believe Barry's know how on this was a result of long experiments and thinking over.

[rando]

The subject of his departure coming up in the last few posts of that thread in no way implied it was ascribed to something occurring in it.  Thank you for clearing this up for me and I agree it is a loss.  For better or worse, industry vets face an uphill battle here.  

 

Is anyone aware of a currently on the market roller bearing design that works better than one that was forwarded by BD?

 

 

 

 

[AnotherSpin]

36 minutes ago, rando said:

 

Is anyone aware of a currently on the market roller bearing design that works better than one that was forwarded by BD?

 

 

I do not know better or not, but these are quite reputable - http://www.symposiumusa.com/allproducts.html

 

[rando]

Thanks, I ask as origin of this conversation started over a decade ago.  If a better reference of design existed we'd do well to focus on it instead to learn from.  Manufacture to an exceedingly lofty quality of production is a major hurdle with our current reference.  I stated earlier any refinement of substance to the roller bearing would be harder to effect than solutions to the air bearing design flaws.  That said, 10+ years is enough passage of time to allow out of reach or developing solutions to fall within reach of cost efficient low production scale.  

 

Our size requirement = scrap billet pieces.  Of which a large quantity of identical dimensions are produced due to economy of scale.  If 7000 series aluminum and exact machining of the cup are more important to function than appearance in keeping with high end environs.  They get much cheaper and simpler to produce in small numbers.  I've seen enough technical proficiency here to feel confident 10 minutes to roll the edges and buff the outward facing surface with metal polish isn't going to be a deal breaker.

 

Barry Diament roller bearing design