Skeletal vs Plinth style turntables

Hi Pryso and Richard, Devcon appears to have soft properties similar to Dynamat or rubber. I lean rather toward passing vibration to earth through mass loading, hard coupling, together with structural improvements that increase mechanical stability of the cast housing and motor. As Richard suggests, maybe at SOTA the stock casting should be discarded. Nevertheless…. the cast housing and motor could be good candidates for treatment via the Flex-tec epoxy system. This epoxy and hardener form a semi-solid that can be sculpted into firm shapes. The casting and motor cavities could be filled and thickened without molds, drips, or overflow. The motor mount bosses could be enlarged to increase rigidity. The epoxy could be filled with brass powder or lead sheets to make a semi-metal or CLD compound, and shaped irregularly to break up and spread out resonant signatures. There… I’ve almost convinced myself to do it.

CT0517, Your skeletal plinth is close to what I have in mind, absent several wrinkles to come. Among other things mine will support 3-4 arms, be compatible with Micro Seiki/Gunmetal pivoting arm bases, and have direct metal-to-metal coupling between the motor spindle bearing and the arm pillars. I’m working with a platform manufacturer with the expectation of making it commercially available for SP-10, Denon, and JVC DD. The business case and cost structure for an initial CNC production run would be improved by anyone expressing interest in this. If so, feel free to PM. Is there room in the market for yet one more supplier of plinths for vintage TTs?

Hi CT0517
Hijack the thread all you like - ;)
You said a few interesting things about the Platine, because the base is very much made of a similar material, by the sound of it, as the Technics Obsidian Bases or the Sony Reisinamic Plinths - both of which use 'resins and stones'.
Likewise Townshend Audio used to use Plaster of Paris.
I have to say I auditioned a Platine, and at the time I was not seduced by its charms - I found it a bit too warm for my tastes. That said - I am not knocking what floats your boat.
With regards to filling in the SP10 - Can I just suggest that you are a bit careful - why not try some lightweight damping such as acoustic foam first of all - what frequencies are you trying to damp?

Hi Chris,

Glad to see you're off the DIY and enjoying the music...as Raul used to say?
Here is a 'suspended' nude Victor TT-81 design using the same idea as your coupling 'plinth'.
It all depends on what one 'means' by a plinth?
If an added shelf sitting on a shelf qualifies as a plinth....well, that's exactly how a turntable plinth acts.
If one removes the 'added' shelf (plinth)....could someone please explain the differences to the mechanical and structural functionalities?
I do appreciate the added 'warm and fuzzy' feeling this can impart together with the ability to mechanically fix the tonearm pods if their weight is insufficient....but apart from that...👀❓

Thought I might just share this image of a cutter on a 'shelf'....?
I think the emphasis on the mass and fixity of the cutter arm compared to the platter shares the thoughts on my Copernican view of the turntable system?

Dgarretson,
The big Micro SX-5000/8000 turntables are well respected but I've never been a fan of their arm-board cantilevered mounting systems.
Here is an example of a DIY project using the Micro system.
The structural integrity of the armboards fixed onto stainless steel poles via friction becomes less and less convincing the longer the cantilever becomes to support 12" arms.
The flexural micro movements in the armboards increase according to the square of the distance of the cantilever whereas there are no deviations in a mass-loaded fully supported armpod.
The fact that these (and others like them e.g. Raven) work....is perhaps an indication that actual micro-movements are still too tiny to be destructive..?
However....like my mate Lew....I just don't like the 'theory'...😎👀