Why not one big nitride ball in a cup, like in the pic?
1 difficulty in sourcing larger ceramic balls
2 in that case the ball to cup has 3 contact points, my design has 1 contact point
3 cost
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Oh yes, and:
4 larger contact area
5 larger energy storage potential
In all the isolation devices, symposium, finite elemente, Stillpoints…they use little nitride balls, instead of Naim who choosed one big ball. But his ball is not nitride I feel?
Correct, Naim balls are chrome plated mild steel.
Hi Xanthe
I’d like to try this out, if possible.
I have 2 racks side by side - both Quadraspire Q4 EVO shelves.
One with glass shelves and the Q4 columns that are I think 19mm straight-sided cylinders.
And the other has oak shelves with the SVT columns that are smaller diameter at the centre of the column and curve out to be 32mm at the ends of the column (see below).
(The shelf diagram shows the size of my shelves, and the photo shows the type of columns I have on my oak rack. But the rack in the photo has a different type of shelf - my glass and oak shelves are all solid and do not have air vents cut out of them.)
I have been wondering whether to get some glass and balls and cups of some sort - so this is of practical interest to me.
Would it be possible to somehow join you in the adventure (without breaking forum rules)?
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Jim, I once had this rack. It’s nice but not very stable. I would not personally put glass shelves with cups and balls on it. Only my feeling.
Better some nice butcher blocks in the same wood color ?
Isoacoustics devices between naim components and the shelves of the rack ?
But @Xanthe may have a more precise and technical answer.
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Solid Sounds do isolation platforms, which have also cups and balls glass supports. Just for interest are their cups and balls much worse compared to Naims native cups and balls? Seems their cup is smaller and has round contact area compared to Naim’s cups, which have triangle pit.
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Yes, iirc MDS has a Quadraspire rack, but his is a much posher version with bamboo shelves and brass metalwork, I think.
The advanatage of my racks is that I bought the pair of them, at spearate times, for a grand total of 200 squid 
- and they are serving well so far, in my preFraim period.
Actually my racks stand on solid concrete floor, and the eight spikes are damped by thick underlay and carpet, which gives them quite a solid basis.
Certainly a lot better than stacking the Naim boxes on top of each other, which I did for the first dozen years I had them!
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Is there less contact between the ball and the cup or the naim 3 point system as the 3 points are just that as opposed to potentially a linear circumference?
Surely this is much worse as the fraim contacts are just 3 points rather than all round linear?
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In that version (I’ve revised it now as, at the time I hadn’t realised that the printer had drifted out of adjustment), the contact between the ball and the ‘cage’ was single point and very light (the cage can move freely and weighs 0.33g). With the new version there’s no contact at all between the ball and the cage (as it was supposed to be in the first place).
In both versions, there is one point of contact between the ball and the glass and one contact between the ball and the cup. The ball sits in a small polished spheroidal depression in the brass; the ball can roll sideways a little (by about +/- 1mm) if external force is applied, but the weight of the component and glass always results in a centring force.
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As you’re in Lancaster and I’m near Bath, meeting up could be problematical.
The forum AUP also says “No For Sale or Wanted ads! (includes free gifts and loans of equipment)”.
Ok, no worries.
I’ll aim to diy it.
So I suppose I’ll need:
- 3 sheets of a suitable type of glass - please let me know if you know a good type eg Pilkington 10mm hardened or Fraim type glass
- 3 balls
made of ceramic you have identified (again any hints as to good suppliers would be appreciated) - 3 small brass cups with height lower than the balls - perhaps I can make a dent in them myself and polish it myself, and find one of the things Yeti mentioned to stop it from moving around??
Should sound better than a random chromed ball bearing…
The glass: 10mm toughened. I’m not sure the supplier of the material makes as much difference as the quality control of how the toughening is carried out.
Silicon nitride balls were purchased from fleabay (grade 5).
Brass blanking plates (for stopping the ends of water pipes) were purchased from fleabay.
The black cage that prevents the ball from rolling too far is a 3d print I designed.
The small depression in the centre of the brass cup was made using a 5/8" grade 10 chrome steel ball bearing (i.e. through hardened bearing steel) positioned using a custom made jig (also 3d printed!). This ensures accurate centring, a good surface to the working area of the cup and also work hardens the area.
Pretty much that’s it! 
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Thanks Xanthe.
That sounds fun and doable with my skill set, ie brute force and guesswork!
Perhaps I could just wrap a strip of gaffa tape around the ball to Restrict its movement within the cup?
Is your jig effectively allowing you to tighten a bolt down onto the top of a chromed hardened steel ball bearing that gradually presses it into the centre of the brass base to create an even dent?
Then polish gently with what grade of sandpaper? Or wire wool?? Using a polish like Brasso??
I’m not sure the gaffa tape idea is a flyer. For the ball used to make the dent it’s too imprecise and too soft. For the ceramic ball it will be in intimate contact (unlike the plastic cage) and add unwanted damping.
I used a much simpler method of making the depression… I dropped a 2kg steel weight on the ball from a consistent 400mm height - consistent energy = consistent dent!
(Even though the brass cup was placed on a strong, flat steel plate, I did have to slightly grind the bottom surface of the cup back to flat though.)
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@Xanthe I have just been scrolling through this thread out of idle curiosity. I already own a Fraim and am not in the market for balls and cups. However I am blown away by your expertise and helpful and generous spirit. Also by your grace under “fire”. It makes the thread a pleasure to read.
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Thank you, that’s nice to hear!
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