Skeletal vs Plinth style turntables


I am pondering a new plinth design and am considering the virtues of making a skeletal or closed plinth design. The motor unit is direct drive. I know that as a direct drive it inherently has very low vibration as opposed to an idler deck (please do not outcry Garrard and Lenco onwners coz I have one of those too) but simple facts are facts belt drive motors spin at 250rpm, Lencos around 1500 rpm, DD 33 or 45 rpm. That being the case that must surely be a factor in this issue. What are your thoughts. BTW I like closed designs as they prevent the gathering of dust.
parrotbee
A further point following Viridian and Ct. When I first became interested in DD tables Corian was often mentioned as a recommended plinth material. But then I read more than one negative comment on that. Further reading disclosed that Corian includes some amount of aluminum flake in its composition. Apparently that varies among samples and that quantity can have a sonic impact. Bottom line, simply choosing Corian may not allow prediction for how it will sound.

Unfortunately it seems to me the best answer is to follow Ct's path and experiment with alternatives.
I know this may seem pedantic, but is there a special glue when gluing together layers - in other words - what glue do the likes of Kronos and Clearaudio use when sandwiching aluminium and panzerholz
Made a table a few years back from Cocobolo laminated with Aluminum, glued the 5 layers (3 cocobolo 2 aluminum) together with a 2 component Epoxy glue, still hold up very nicely. The aluminum layers were "timesaved" which is the typical graining you see on for an example your typical Face Plate.
System 3 Epoxy

Good Listening

Peter
Some 20 years ago when I was building my current SP10 MK3 plinth, I spent a lot of time experimenting with glues.
I was using CLD on the acrylic top plate. In this case a 15mm layer of lead was to be adhered to the acrylic.
I initially thought that a lossy type glue, such as ados, would be optimal but listening to the test pieces thru a stethoscope while tapping it gave a "thunk" type sound. This was not what I expected as I was trying to emulate the ideal water fall type plot as we see published in speaker tests.
That is a sharp rise time with very little tail to the sound.
I then started experimenting with epoxy glues and settled on an industrial araldite epoxy. This lead to protracted experimentation with harder and filler ratios. I found that I could further reduce the tail of the tapped sound by optimising the hardness of the glue.
The final result gave a very short sharp "tic" when the workpiece was struck.
The result was a kind of fusing the acrylic to the lead. In this way they behave as a intimate composite structure.
Aiding this was massive clamping pressure while the glue dried. Over one tonne of cast iron billets were stacked on top of the plinth during the curing time.
Epoxy heats up when mixed, so the glue becomes quite runny. The vast majority of it oozed out between the layers. Unwilling to let this excess set, which would have required expensive remachining, I spent almost all night until just before dawn removing the excess as it flowed out.

Fun.
Viridian et al, You guys may be missing the point of what Atma-sphere wrote (at least as I see it). The point is that whatever the resonant signature, it is critical that the tonearm and platter be "connected" so they resonate as one piece. The problem with outboard arm pods (again, as I see it) is that they separate the tonearm from the bearing/platter, and no matter what you do after that, the two entities are independently subject to environmental energy sources; they'll then move or vibrate differently in response. Best you can do is make them very very massive so that most energy is dissipated as heat rather than movement. This is/was essentially my longstanding argument with Halcro vis a vis outboard arm pods. My metaphor or thought experiment is: Think of yourself trying to cut a diamond while seated in a row boat floating on water. Now think of yourself trying to cut a diamond whilst you are sitting in one rowboat and the diamond and all your tools are in another separate rowboat. Which is easier to do accurately?