Tables That Feature Bearing Friction

Ah, so now we are cutting to the chase.

In the real world, there are always compromises. Even the equations that we use to model real world behavior have compromises built in. One can certainly chose which to address, but on cannot avoid accepting compromise in one way or another. Even if one is not aware of the compromise(s) at the time. That is the leap from paper to reality. EVERY system, mechanical or biological or whatever, in the universe has built in compromises. It is unavoidable. So I propose that we drop the pretense that any system can built without compromises.

I agree that all turntable designers/manufacturers will make decisions based on commercial interests. Absolutely. They want to be able to sell what they have made. However, even those who profess to have spared no expense and made no compromises are deluding themselves, IMO. Look closer, I say to them. Compromises are there.

Dear Dan-Ed, yes, are you happy we arrived in the "real world" (was Neo happy when Morpheus showed it to him...?).
Of course, compromises are there. WHERE they can not be avoided I agree to them. However - I can't stress this often enough: the one basic fault is to make the compromise the goal. And that is what is happening all around and what gives us what we deserve: .... mediocrity or worse.

My point is that the compromise is o.k. when there is no close to ideal (= near perfect ) solution possible.
However - once again and for all - it is NOT nessecary in turntable design.
To accept "compromises" here in the early stadiums we see them in almost all turntables around - those are not compromises.
That is poor, unfinished design.

Named "compromise" just because the designers could not do any better or did not want to go any further (for whatever reason...money , time, market call).

"Unevitable compromises" in a machine as simple and small as a high-end turntable............... really, give me a break - we are in the 21st century not in the dark ages of mechanics following the decline of the roman empire !!!
Its poor performance - not unevitable compromise.
Period.

Dertonarm, For your consideration, an idler-drive in which the motor force is applied to the underside of the platter, in the vertical plane. Thus no horizontal force needs to be cancelled. No string needs to be chosen or "adjusted". In short, I offer you "Super-Lenco". Take a look at the Saskia turntable. (I know you will dislike the possibility for idler wheel "noise" to be transmitted into the platter, but this is the real world where choices have to be made. Believe me, that turntable is silent.) Put a Saskia on a Minus-K or an industrial isolator for an electron microscope, and you might be in vinyl heaven.

However - once again and for all - it is NOT nessecary in turntable design.

Sorry to use a caloquialism, but I say bullshit! :-)

Since we are on to the drive system in this thread let's use that. For the table that you designed. Did you not find that proper tension on the pulley was critical? Did your math/physics models predict that? How did you find, repeatably, what the correct tension should be?

Let's look at the motor. DC or AC? How about the controller? If you open the doors I bet we can find your compromises. I'm not trying to pick you apart, just your position that no compromise should ever have to be made when building a turntable. The human experience over the last century with building LP playback machines shows otherwise.

Now we can always argue over the compromises that ARE made. That is the sole reason for forums like this.

Dear Dan_Ed, I can't offer the eloquence displayed in your opening sentence of the last post, however I will once and for last try to clarify my point:

Compromises where they are inevitable.

As for the questions asked:
- no, string tension was not that critical - it just prolonged the time frame to full speed.
- yes, it was no problem to find repeatably the right tension. I had a calibrated spring gauge and a laser to determine it.
- DC and / or AC - as I wished. The controller was the control board from the Studer fortified with a custom build amplifier to create the signal.
There were compromises in my early design too. Some I did only detect years later.
None that were detected by others. None that others detected in their designs ever.
Thats why I am doing it again this summer and autumn.
But even if I go on and on with the details it will not cure the problem.
Me insiting on the "no need" for compromise in turntable design seems to be a kind of sacrilege to some.

The human experience shows us that it took almost 8 Millenias of civilisation till democracy took over on a larger scale.
Does this proof anything??
One century of turntable design. Maybe. But only the last 30 years did came up any turntables trying to be "state of the art". So its pretty young an evolution. Shall we give up now? Seems as if quite some people would prefer things to stay the way they are.....

Sorry, - somehow I am missing the point........

I would much more prefer to return to technical facts and hypothesis then debatting about my unability to realize that inevitable need for compromise.

There must be something extremely tempting and attractive about finding early compromises and life in peace with them ever after.

I am sure I am just too simple minded to see and realize that attractivity.
Poor me.