094 Fascinating Magnetic Toy 1: Magnetic Seal

The manufacturer provided the diagram below, which shows the magnets in the seal and ball to be misaligned by 45°.


You may want to refer to the manufacturer’s write-up on how this results in the rotational motion of the ball (because I have not figured it out yet).


The magnetic spinning ballerina works by the exact same principle.

2 thoughts on “094 Fascinating Magnetic Toy 1: Magnetic Seal

  1. Mr Chua! In the data sheet, for figure 3(last page), when they say that it will tilt about point P, does it refer to the axis that’s into and out of the page? Like it’s tilting towards me? As for the repulsive force due to the the vertical component of the seal’s magnet, the force is acting solely towards the right, right? If so, then is it right to say they will produce a resultant force that leads to the spinning motion? 🙂

    1. My understanding is as follow: My viewpoint is from the seal looking at the ball. The vertical components of the seal’s magnet is trying to push the ball away, but the ball practically stays put because of friction. The horizontal components of the seal’s magnet is trying to rotate the ball sideway, but again the ball more or less stays put, thanks to friction.However, this torque is enough to tilt the ball slightly (leftward or rightward). Now back to the vertical components of the seal. Because the centre of mass of the ball has been tilted away, this repulsive force now has the the additional effect to rotating the ball about the vertical axis. Hence, the ball started spinning.

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