: Bessler's translation on this site describes a "principle piece". He goes on to say its a rotating disk or cylinder around the firmly placed AXIS, not axle.
: It resembles a grindstone. John Collins informed me that JB worked on flour mills. A little research into flour mills reveals that they use a roller and ring
: pulverizer to grind flour because burrstones run close enough toghether to make flour-consistancy scorches the flour or starts a fire. So one ends up with a circular track around a pivot. To get
: the pendulum to offset, a link is run out from the center of the ring to just inside its I.D. The pendulum is attached to the end of this link. Below that point a roller is attached to the pendulum stem, and is in contact
: with the cylinder's I.D. The link's attachment to the central pin is through a bearing, so it can turn 360 degrees.
: The pendulum tries to hang straight down, but because it is on a link, the radius it must traverse to hang straight down is blocked by the cylinder's I.D., like trying to turn a couch in a tight hallway.
: The pressure exerted by the pendulum's seeking equilibrium causes the roller to climb the inside of the cylinder wall, and the whole assembly floats there, bouyed up by the force of the still-unequilibriumed pendulum weight.
: There is pressure exerted on the central pin, as Mike said, and that is verified by using an oversized bearing at the point and observing.
: If one pulls down on the pendulum, it climbs back up. If one raises it, it goes back down and floats at its original position. And no matter how one turns the cylinder, the pendulum maintains its position.
: It matters not if 1/2 pound or 25 lbs are hung as the pendulum weight, the geometry makes it climb and float at that same position.
: With the weights hanging down, the "unicycle man" syndrome showed up. The next step when time allows is to put the large pendulum weight above the axle line using at least a six-to-one lever, light construction, with a
: ten-ounce weight counterbalancing 2 1/2 pounds, the COG should still fall offset above the axle line.