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
should have waited till I was fully awake and finished my coffee before I hit submit.
sorry for the errors - extra words that don't belong.

A case of mind and fingers not in sync yet.
LOL - to edit the post in this forum database, would seriously throw out my carefully thought out paragraph alignments. :^)
l am going for my run instead.
I tapped the armpod and shelf (plinth) with a metal object whilst the stylus was on a stationary record...and the tone of both was near identical.

I was referring to the sound you get not through the speakers but just the sound of the metal itself reacting to being rung by tapping it with a metal instrument.
I mentioned the mythical perfect TT earlier on this thread.
item 2) was " Perfect dynamic dimensional stability"

We have seen on another thread here how stylus drag can slow the platter. This even where massive platters and drive systems are employed.
This drag is pulling on the arm and hence its support. In the case of a nude TT, the pod is being exposed to this force. If this heavily modulated force is sufficient to slow a weighty platter of considerable inertia, would it not also be able to "tilt" a free standing pod even, if it is substantial?

Way back in high school we were tasked with this question..
What happens when you throw a snooker ball such that it hits the front of an oncoming train. The answer is that the train slows, and with relative weights and speeds, we were able to calculated how much.



Regards, Richardkrebs: Would stylus drag then be considered an irrestable force?

Just imagining the tensions these forces are exerting on tonearm bearings, the headshell couplings and the bearing wear. not to mention misalignment consequent to the rending of cantilevers as the stylus drags a seven pound pod around leaves me marveling at the complications overcome in the analog realm.

Or perhaps this might be a reductio ad absurdum (referring to my comments, of course)?

---Just an enthusiasts' mutterings amidst the opinions of experts.

Peace
Dear CT 0517

you say:
I used to say to myself ...hmmmm looks like a hole / space there. Wonder what would happen if I filled it ? When an audiophile based on theory alone, said don't do that, its not right because of xxxxxxx, but showed no real direct experience with it himself...... ..Hell..the more reason to go and do it.

This is a tad unfair given that you don't know what I do do, and what else I have built and fiddled with.

But FYI i have made a few Lenco plinths, and have also fiddled (that's what I call it) with a few belt drive decks to. In addition to this I have built quite a few speakers. In my experience when you keep mass loading you effectively just restribute the vibrations to a higher frequency often. The strangest/worst thing one can do is fill up a plinth with some type of permanent resin, and then be unable to remove it, or indeed sell the component due to the over-enthusiastic 'intervention/innovation'

As to the Obsidian - I never knew it was glass - I had always thought it was a non-resonating composite like the one on the SONY TTS - learn a new thing every day.