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    For the man who has everything . . . a levitating turntable

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    deepee99

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    For the man who has everything . . . a levitating turntable

    Post by deepee99 on Tue Dec 13, 2016 11:30 am

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    Peter W.

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    Re: For the man who has everything . . . a levitating turntable

    Post by Peter W. on Tue Dec 13, 2016 11:54 am


    There was much speculation on this in another venue. Mostly highly skeptical. Having seen magnetic levitation in the past, I came up with a sketch that, although wildly speculative, does cover the basics. After which is my further wild speculations.

    https://www.dropbox.com/s/huq5ehstsoe0cbo/maglev%20wild%20speculation.docx?dl=0

    a) Neodymium magnets are wildly powerful. And can be shaped more efficiently than many other materials.
    b) By offsetting the suspension rings as shown, the forces centering and keeping the platter level would be very strong - certainly stronger than most suspension springs for that matter.
    c) And there would be negligible elastic forces - that is, no wobble or bounce. That window fan would not have a chance. Damping, similarly.
    d) The wow and flutter issue, though very real, would be pretty much eliminated by the mass of the platter (considerable) coupled with the very negligible mass of the drive motor.
    e) As the platter is essentially frictionless, it would not take much to keep it running once started. I would anticipate a few seconds of start-up, but after that, gyroscopic effects would contribute to leveling and to speed control. The couple of grams on the stylus, again, would not have a chance.
    f) The soft shut-down is already addressed. There is an on-board soft shut-down capacity that will raise the posts and lift the stylus.
    g) As to magnetic fields - consider that both the suspension field and the drive fields are static relative to each other. Meaning that there will be very little generated by way of stray fields, and that the platter, if properly designed, will be enough to shield the cartridge. Considering what goes on inside my HK/Rabco without ill effect, or my Revox B295, this would be low on my worry-scale.

    Again, this is a neat trick, not something I intend to purchase. But a neat trick that appears to be both possible and reasonable to execute.

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    arledgsc

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    Re: For the man who has everything . . . a levitating turntable

    Post by arledgsc on Tue Dec 13, 2016 12:06 pm

    Would the power magnets affect the cartridge coils and the very tiny currents induced during playback? Seems the platter is rotated by a moving magnetic field which has the making for a generator with the static cartridge.
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    Peter W.

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    Re: For the man who has everything . . . a levitating turntable

    Post by Peter W. on Tue Dec 13, 2016 12:49 pm

    arledgsc wrote:Would the power magnets affect the cartridge coils and the very tiny currents induced during playback?  Seems the platter is rotated by a moving magnetic field which has the making for a generator with the static cartridge.  

    Not really. This would be no worse than a direct drive TT using a conventional motor - less so, actually as only a fraction of the energy would be required to turn a very nearly frictionless platter. The platter itself would also be a shield - as they are on conventional devices.

    Keep in mind that the very tiny energy requirements of the system suggest strongly that the suspending primary magnet is not electric, but also a permanent magnet. Hence the need for extendable legs when the platter is at rest. So, as there are no reversing poles, the rotation will not generate any current in the suspending magnets, nor any stray fields. Quite elegant, in my opinion.
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    deepee99

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    Re: For the man who has everything . . . a levitating turntable

    Post by deepee99 on Tue Dec 13, 2016 12:54 pm

    I guess we'll know the answers soon enough, because you know at least one of us crazy OCDs is gonna buy one.
    Actually, for a kilobuck it's certainly on the bottom of the price point for upper end spinners.
    Mag-lev technology has worked for a decade or two on Asian trains. Different application, and I would have concerns about cartridge noise. But the concept is fascinating. So please, somebody buy one and let the rest of us know. The idea of a floating platter would certainly be a chick-magnet.
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    Tube Nube

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    Re: For the man who has everything . . . a levitating turntable

    Post by Tube Nube on Tue Dec 13, 2016 1:26 pm

    ...but what good is a chick, magnetically stuck to a heavy freefloating turntable platter?
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    Peter W.

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    Re: For the man who has everything . . . a levitating turntable

    Post by Peter W. on Tue Dec 13, 2016 1:39 pm

    Tube Nube wrote:...but what good is a chick, magnetically stuck to a heavy freefloating turntable platter?

    This is one of those "if you have to ask..." situations.
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    deepee99

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    Re: For the man who has everything . . . a levitating turntable

    Post by deepee99 on Tue Dec 13, 2016 1:41 pm

    Peter W. wrote:
    Tube Nube wrote:...but what good is a chick, magnetically stuck to a heavy freefloating turntable platter?

    This is one of those "if you have to ask..." situations.
    Guess it depends on the jewellery she's wearing.
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    10-E-C

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    Re: For the man who has everything . . . a levitating turntable

    Post by 10-E-C on Tue Dec 13, 2016 1:50 pm

    deepee99 wrote:I guess we'll know the answers soon enough, because you know at least one of us crazy OCDs is gonna buy one.
    Actually, for a kilobuck it's certainly on the bottom of the price point for upper end spinners.
    Mag-lev technology has worked for a decade or two on Asian trains. Different application, and I would have concerns about cartridge noise. But the concept is fascinating.  So please, somebody buy one and let the rest of us know. The idea of a floating platter would certainly be a chick-magnet.

    I've seen this technology used it the drive axis of CNC machines. Oh what fun it was being an electronic maintenance tech for many years.

    TM
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    Dave_in_Va

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    Re: For the man who has everything . . . a levitating turntable

    Post by Dave_in_Va on Tue Dec 13, 2016 3:03 pm

    That thing is SUPER cool!
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    sKiZo

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    Re: For the man who has everything . . . a levitating turntable

    Post by sKiZo on Thu Dec 15, 2016 3:33 pm

    Just a prelude to invasion ...



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    Peter W.

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    Re: For the man who has everything . . . a levitating turntable

    Post by Peter W. on Thu Dec 15, 2016 3:39 pm

    Well, it is absolutely certainly the case that any invading group would not be benign. Probably not such pushovers, either. At the same time, our Dynaco tube stuff would survive an EMP where very nearly anything with a programmed or programmable chip would not.
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    sKiZo

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    Re: For the man who has everything . . . a levitating turntable

    Post by sKiZo on Thu Dec 15, 2016 10:01 pm

    Yup, the only casualty would be the Capitol dome in DC when the platter from your levitating turntable takes off and goes crashing into it ...

    You gonna have some splainin to do!

    PS ... is it just me, or do I see some serious wobble in the Z axis when that thing is spinning?
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    deepee99

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    Re: For the man who has everything . . . a levitating turntable

    Post by deepee99 on Fri Dec 16, 2016 1:35 am

    The Z Axis would only be of concern after the Pulse.
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    sKiZo

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    Re: For the man who has everything . . . a levitating turntable

    Post by sKiZo on Fri Dec 16, 2016 7:50 pm

    The Pulse?


    Dogstar

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    Re: For the man who has everything . . . a levitating turntable

    Post by Dogstar on Sun Dec 18, 2016 2:11 pm

    I'd like to see the levitating turntable on top of my flying carpet.
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    Dave_in_Va

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    Re: For the man who has everything . . . a levitating turntable

    Post by Dave_in_Va on Wed Nov 22, 2017 10:41 pm

    Did anyone get one of these things?

    ramon68

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    Re: For the man who has everything . . . a levitating turntable

    Post by ramon68 on Thu Nov 23, 2017 12:23 pm

    Imagine the difficulty in achieving absolute speed accuracy with no mechanical linkage between motor and platter and no absolute reference point for the platter's pivot. I'm betting this thing sounds like crap. Just saying.
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    Peter W.

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    Re: For the man who has everything . . . a levitating turntable

    Post by Peter W. on Thu Nov 23, 2017 1:28 pm

    ramon68 wrote:Imagine the difficulty in achieving absolute speed accuracy with no mechanical linkage between motor and platter and no absolute reference point for the platter's pivot. I'm betting this thing sounds like crap. Just saying.

    Actually, speed and centering, as well as vertical stability are the easiest of the problems to solve. A hall-effect motor will give absolute speed control. Off-setting the repelling magnets and the rotational forces will hold center equally well. There are quite a number of 'air bearings' that do this sort of thing without the magnets. And given how crude (yes, crude by any level of precision engineering standards) a turntable really is, this would be a walk in the park. The arm - that is a different story.

    https://www.dropbox.com/s/huq5ehstsoe0cbo/maglev%20wild%20speculation.docx?dl=0

    I worked in a machine-shop for a few years on the inspection and final-production lines - all the machinists shared across the spectrum of responsibilities - and I know that our shop could do this. In any case, this is my proof-of-concept sketch. No actual moving parts but for the platter, and no hard connections between anything to anything. And a couple of grams of stylus force and drag on a platter that will be (at least) a couple of kg will be meaningless. The neodymium magnets will not be cheap, however.

    Enjoy.
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    deepee99

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    Re: For the man who has everything . . . a levitating turntable

    Post by deepee99 on Thu Nov 23, 2017 6:34 pm

    This project was crowd-funded and I got in early, so either I've got a $700 POS or a $2k jewel.
    As for Mag-Lev technology, I've never heard of one of those Asian mag-lev trains jumping the tracks.
    The proof in the pudding will be in how well the pre-installed Ortofon handles all that magnetic interference.
    Doubt no matter how perfect it is, I'd ever swap it for my Thorens.
    At any rate, guinea pig reporting in. Film at 11. Their communications have been very good and clear, and am expecting delivery any date now.


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    Dave_in_Va

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    Re: For the man who has everything . . . a levitating turntable

    Post by Dave_in_Va on Thu Nov 23, 2017 6:50 pm

    Deepee,
    Please post some pics when you get it set up.

    Dogstar

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    Re: For the man who has everything . . . a levitating turntable

    Post by Dogstar on Fri Nov 24, 2017 2:45 am

    That will be pretty cool if it really works as good as I'm sure we all hope it does. The only shortcoming I see is that 'imitation wood' version. As if having a finish reminiscent of 1970's Pontiac Grand Safari station wagons made from contact paper makes it a more desirable item.

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