What/where do you search for to find the brass thingy??!
Wow, that is an absolutely stunningly amazing tolerance claim: ceramic balls 12 +/- 0.000 mm diameter! 0r Perhaps should I have said totally and ridiculously probably impossibly false claim!
(But that has no bearing on their suitability for this use)
Fantastic - thank you!
According to that well known engineering standard, grade 25 should be plus/minus o.oo25mm. But a load of old tosh by putting that tolerance on the wrapper. But as you say, for this application is doesn’t matter
Can’t get a decent picture of the dent. There is a clear radius, just can’t get a decent picture.
No worries.
Thanks for trying.
It was mainly for posterity and to help others who try it in future.
But your detailed instructions on how you did it will be useful enough.
The brass cups i used already had a nice dent in the middle and just need a bit more to be perfect for the 6mm ball, see my post on the other thread for pics
Dunc- which thread are you referring to? Save me searching the forum.
Thank you in advance
Jonathan
Ah - just seen this.
You went for Alumina.
On the other thread Xanthe recommends Silicon Nitride, which is what I got iirc.
Just looked it up.
I got this from mcr-spares-online on a popular auction site:
Ceramic Si3N4 Ball Bearings G5 1/4" bag of 15 spheres for £10.
You know more than me! It’s ceramic and damm hard!
Not sure whether silicon nitride is harder or not.
If I try some different ones, I’ll give the silicon ones a go.
http://www.keranova.se/Engelsk/Exceltabell_E.htm
This table gives a range of figures for Si3N4 and Al2O3, depending on production method and purity.
And they appear to be roughly of similar hardness.
Comparing just on price the aluminium ones are about one tenth of the price of the silicon ones size for size.
One slight advantage of the bigger balls, is being able to get your fingers under the glass to position it. Sort of discusses that in the original thread. But they do cost more.
Anyway, balls under TT and streamer. Let’s see how it goes.
Yes, I use Xanthe’s technique of putting 3 chocks of wood that are thicker than the height of the brass cup and sphere before lifting the component and glass as one to get it on or off the shelf.
Then my big clumsy fingers can get under it ok!
I might try that if I put my 40kg power amp on a shelf!
Where else are you planning to put it?
If you like them why not put suspended glass shelves under all components?
I might do. No real plans but I do have a piece of glass that would fit under the power amp. And, I’d need the smaller balls so that I don’t reduce the clearance to the next shelf too much. And I have four brass things spare. Just need the balls.
Shifting the power amp into place is the difficult bit. Not just because of the weight. It’s at the bottom of the rack and best tackled with the rack in bits😠
The amp will be vibrating the other components on the rack and also being shaken by their movements.