Vibration isolating rollerballs

[AnotherSpin]

As I understand, the question of design/measurements of bowls for group buy is open. In one of his posts in other thread Barry gave an idea of some measurements (not all) he used. I am sharing the design (everything is in mm) which I used for the bowls I have already for some time. It were machined before I saw those mentioned Barry's measurements (which I would use myself if I knew it then). But, Barry hinted he have some new ideas, maybe he will tell us more now... Anyway, let's discuss.

 

[AnotherSpin]

I quoted 1.8mm -- that's actually 1/8 inch depth. section of a 2" sphere. So diameter 2".

 

Much of the work involved is in setting up the machining. I suspect that there would need to be some minimum number of sets for a run of 6061 but he may keep 6061 in stock. I'm interested in 7075. If people are also interested in 6061 we could use this thread to get a rough number and then ask Ingress.

For us, visuals, is it possible to see how selected design for group buy may looks a like? And, no discussion here? No input (possible) from Barry?

[AnotherSpin]

You are the only one who has ever provided a drawing! I'd be happy if you converse with Mike [email protected] and come to an understanding of what is possible given the constraints of what he's ordered in terms of material and reasonable price. Mike wants to make something that we like. I'm happy to go with either the spec Barry gave us already, or yours if that meets the manufacturing constraints or something in between.

 

Jon, I wrote to Mike with question and drawing enclosed. I think we could use my design with one change - inner curvature diameter should be 2" as in Barry's idea. In fact, this is the most important part, and I believe we should go with Barry here.

[AnotherSpin]

The resonant frequency of such a system would be mainly set by the radius of the cup. Larger radius, lower frequency.

Alu bowls which I use have bigger concave radius than those in Barry's (2.7" against 2"). Nevertheless, I would love to try a new set of bowls made on Barry's measurements. My premonition (and quite strong one) tells me Barry came to this most important dimension for a reason. I use the same size bearings he does.

[AnotherSpin]

The proverbial straw was that he doesn't want to "spend an hour" polishing each bowl.

It is hard part - I did polishing myself after got bowls from machinist.

[AnotherSpin]

If you folks want to try something that can also look very cool, try two pieces of 5/8" or thicker glass with the contacting pieces coated with glycerol which will act as a continuos bearing across the entire surface. You can also add a phosphorescent pigment to the glycerol and an LED lamp at the rear producing a distinct glow between the two layers.

 

When first assembling, some glycerol will be forced out of the sides but once it sits with the gear on top it will stabilize with cohesion within the liquid and not the glass.

Would you share a pics of working solution, please?

[AnotherSpin]

Hi Jabbr,

 

What might be the cost for these bowls?

[AnotherSpin]

Re the marble tiles, are there any threads discussing No- or Less-ringy marble tiles? My Home Depots have only one sample, which is about half-ringy as ceramic or porcelain. Flooring shops have small samples on backing boards, or "faux marble", which btw is dead but faux. And online, marble does not seem to be offered by type, flavor or characteristic resonance. Barry had once mentioned his preference for less-ringy marble. I am unable to pick uo any specifics on what type(s) work, or what name they go by commercially.

 

Thanks in advance for any ideas.

 

I have bad experience with marble. Selected most beautiful natural mediterranean 2 cm marble which was less-ringy from huge variety to which I compared it to be cut to my measures only to see afterwards that its polished surface was dented by chrome balls when used under heavy speakers. Natural marble is not hard and may be crumbly, and this quality should be considered. My suggestion would be to collect and try several different hardest plates from various materials. I believe hardness is no less important than ringing at least.

[AnotherSpin]

The bowls cups need to be in qty to be cost effective (obviously) and I had some crazy $ quotes and lead times from various shops, but through my connections was able to get them well under $20/ea (7075, polished). As far as making them, it took a 1 hour machine set up time, but the cut time is very quick.

 

 

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These bowls looks very good! I hope you will be happy with results.