Video of motorized top - is the explanation correct?

[Swamp Thing]

Is the presenter's explanation correct in all respects?

And has anyone seen one of these "in person"?

 

[A.T.]

Is the presenter's explanation correct in all respects?

Too vague to tell. But while it is tilted, the contact point on the rounded bottom is off-axis, so the friction there can create a torque that adds angular momentum.

 

[anorlunda]

When I saw the word "forever" in the title, I thought it was another perpetual motion machine. Not so; he didn't mean forever. Nevertheless, it is too complicated to analyze simply.

When we do scientific experiments or blackboard proofs of principle, things are made as simple as possible. In the real world, devices can be arbitrarily complex and difficult to analyze. Compound that with a natural language explanation instead of math, and it becomes even more difficult. Now the OP is asking for a counter natural language explanation. No thanks.

 

[Arjan82]

Haven't seen one in RL, but I'm guessing this is the rotational variant of a swing set. Explanation seems legit for as far as you can judge it, because I agree it is a bit vague.