td-01 chinese tonearm?

the weight of the arm holds the ball into its oil dampened socket and the string is just used to keep the arm aligned from side to side so it doesnt just fall over.

I thought the string hangs the arm and the ball is inside the oil well but not touching the bottom. Instead of using a magnet, like Schroder, to stabilize the arm from swinging all over the place, the designer use an oil bath to damp unwanted movement. I believe this is the same seller who infringed the Schroder patent and Frank took action against it and now he came up with a different design. Instead of magnet, now it's oil. Very similar concept to the WTA.

Your idea would work too but is closer to a classic unipivot design with the assist of a string for stability.

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I'm not sure I'd agree that it's a similar concept to the Well Tempered arm. There can't be more than a drop or two of damping fluid in the well of the TD-01, and the contact area of the ceramic ball is very small. The amount of damping would be miniscule compared to relatively gigantic paddle and fluid well of the WTA. Also, no easy way to adjust azimuth as on the WTA.

Not saying it wouldn't work, or even be better than the WTA; just saying the concepts aren't that similar.

David

I think the ball would have to be solidly in the receiver for this tonearm to work at all, with the weight of the tonearm holding it in place like any other unipivot, otherwise it would be swinging around all over the place. Armstrod is right that there cant be more than a drop or two of oil in there, not like a well tempered that has an fluid bath. And the only way to adjust asimuth would be by turning the counterweight and locking it off center. there must be a way to adjust the lenght of the string so it is tight, but allows the arm to sit firmly in the cup.

By the way, does anyone remember a system that used 3 ball bearings on the bottom in a triangle with one ball bearing in the arm sitting in the middle in a kind of unipivot arrangement that was much more stable than your usual pinpoint pivot?

Manitunc: "By the way, does anyone remember a system that used 3 ball bearings on the bottom in a triangle with one ball bearing in the arm sitting in the middle in a kind of unipivot arrangement that was much more stable than your usual pinpoint pivot?"

I believe you're talking about the Hadcock tonearm. Here's an excerpt from a review in 6moons:

"So, with a blast of trumpets, let's now unveil the £689 Hadcock 242SE. It looks like a conventional unipivot, except it's not. The needle point isn't so much a needle as an elongated cone tip. The cup isn't a cup at all because it holds four tiny brass balls to act as a bearing. So it's a compromise, really - a semi unipivot, its scale reduced to virtually act as a unipivot while producing the greater stability inherent in a dual-pivot design. Very clever, you say - but does it work? Let's find out."

Here's a picture.

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Nope, thats not it. I have a Hadcock and its not what I am thinking of. Maybe a Helius or a Basis Vector. 3 balls creating a triangle, with a 4th ball in the center and raised above the other 3. Maybe I just thought of it?