I can’t explain how it really works, what are the best materials to use…
But , as you see on these 3 well known and acclaimed isolation devices using ceramic balls, there are multiple points of contact, not one, and I see no brass but stainless steel or aluminum.
FR let me assure you that I do know how they work (hence I was able to design an effective system).
And as you and Pedder are always insisting that I should listen to things (most of which don’t actually make any sound! - smiley specially for Pedder!) perhaps you should do the same here and trust @JimDog and myself who have listened to a system before and after installation of the brass / silicon nitride / toughened glass system!
I am absolutely not saying that your devices don’t work.
Just to point that the best known isolation ceramic devices in the audiophile world, as Stillpoints and Finite elemente, don’t use brass and have multiple points contact.
But if you think that your devices work better, for few pennies, you should perhaps file a patent.
And to end, I believe your isolation devices work very well. Jim has already testified.
But you can’t say that brass is the best of all material, and multiple points contact don’t work. Just that.
But have you worked out why they use multi point contact?
(Half the answer lies in the last of the pictures you posted above, the other half is the obvious one!)
And I didn’t say that brass is the best of all materials - with more commitment to engineering I could better my own design, but that would necessitate a lot more mathematical modelling work, a lot more research, a lot more engineering work making prototypes and a lot more work testing those prototypes!
I replied originally to you because you wrote that the ceramic isolation device I posted ( the cheap one) has a lot of limitations.
However it looks quite similar, but less over engineered, to the well known devices I posted after.
Just because something looks similar doesn’t mean it will function the same (as I’m sure you understand).
Also, I didn’t say it has “a lot of limitations”, I just said it has three limitations - without even specifying if I consider each of them to be minor, major or critical limitations, indeed, for one of those limitations, I explicitly stated that I was unclear as to the magnitude of severity.
It would be interesting to test each of the designs, but I don’t have suitable test equipment…
I could buy the test equipment, but I can’t justify the considerable expense to do that; or I could make it, but I’m not going to bother with all that work (and still reasonably significant expense!).
Yes the brass plates I put up would have been machined to form the recess I guess. But I should think they are fine for the job and probably better and more precise than hitting it with a hammer/ball bearing would ever be.
As you stand a good chance distorting the brass hitting it as it’s a soft metal.
It’s a nice recess at the moment and I should think a 5.5 mm ball would sit in it very well and give a small gap above the brass for the glass to miss, with out the ball having a large contact area on the brass. But without a suitable ball I can’t 100% say, or if it will sound any different from what I use now
maybe the thing to do is get some of duncs brass end caps and use a press (fly) and hardened steel ball of the same profile and press it into the depression using a known force.
Then ensuring the base has not distorted (if it has, then flatten) and try a silicon nitride ball.
If it gets anywhere near Xanthe and jimdogs improvement from their design surely it would be deemed a success.
Rather than using a fly press and applying a known force, I used a solid steel mass to apply force to the bearing ball; by dropping a known mass form a known height, thus applying a fixed amount of kinetic energy…
i.e. directly analogous to the known force of the fly press!
But feel free to use a fly press (or hydraulic press!) if you have access to one (less dramatic but just as effective).
(And yes I re-ground the back of the brass cup afterwards to ensure flatness, leaving this coarse ground also reduces the likelihood of the brass slipping so much on the shelf when in use.)
Well ordered some 6mm balls today, so going to give it a go.
Also hammered a 10mm steel ball into the recessed area to make it a bit wider for the 6mm balls, but looking good and should fit nicely