Michell Gyro SE TT bearing and ass'y pics

Discussion in 'Vinyl Nutjob World: Turntable and Related Gear' started by Puma Cat, Apr 30, 2020.

  1. Puma Cat

    Puma Cat Almost "Made"

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    When re-positioning my turntable today on the audio rack, I noticed that the platter for my Michell Gyro SE appeared to have a very slight wobble. I took the platter off, and the removed the inverted bronze bearing and noted that, over the last 10 years, the bearing spindle/oil reservoir subass'y had unscrewed very slightly from its threaded hole in the main TT frame. I took the opportunity to take the inverted bearing and platter off to clean things up and polish the bearing and platter weights. I thought folks would be interested in seeing another belt-driven TT design that is comparable to the Schiit Sol in that it utilizes an inverted bearing, a three-point frame, and an external motor pod. It is designed so that you can mount the arm of your choice (though it was designed by John Michell using the SME V shown here as the reference arm).

    First up is a pic of the frame and acrylic sub-frame. The subframe supports the feet and locates the spring "shock-towers." The main frame uses springs for isolation, and the springs system is "inverted" so that mass of the frame keeps the spring set to an ideal preload for isolation rather than the Linn design, which compresses its springs.

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    You can see that the motor is precisely positioned for correct belt tension by an "ear"on the main frame that the motor pods sits in. The frame does not contact the motor and is free to move up and down to damp vibrations. The motor is a DC motor, so there is no speed oscillation from the AC mains frequency.

    The bearing spindle sub-assembly threads into the hole in the frame, and has a cup which provides a reservoir for the bearing oil. The hole you see at the top is to allow the oil that is carried up along the bearing shaft by a "rifling-style" thread in the inverted bronze bearing to drain back down to the oil reservoir.

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    The inverted bronze bearing sitting on the bearing spindle. This bad boy spins for a looonnng time when the platter is in place.
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    The bottom of the platter with the plated brass weights all polished up. The weights add mass to the platter to provide rotational speed stability and minimize rotational speed variance.

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    The platter back in position on the main bearing. The platter is made of a special polymer that matches the resonance characteristics of LPs but is also very hard. No mat is used with it. While it is a polymer, it also feels like metal.

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    A close up the motor and platter showing the groove in the platter than the belt runs in so there is no "belt wobble".
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    All buttoned up and ready to hit the town...
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    Last edited: Apr 30, 2020
  2. deniall83

    deniall83 Acquaintance

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    Beautiful. I think this is my dream belt drive table but fuck they are expensive in Australia.
     
  3. Puma Cat

    Puma Cat Almost "Made"

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    Yeah, I hear 'ya, buddy. I've been to Australia 3 or 4 times, and with the taxes, stuff is just really expensive. I was shocked the first time I went to Australia to present at the International Association of Forensic Sciences conference in Adelaide, and heard how much a car costs to buy. I still have some good mates in Oz.
     
    Last edited: May 7, 2020

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