I have an old toy which is just a small box and it has 2 small ball bearings inside. The idea was to get one ball bearing in the hole on the right and the other into the hole on the left. I remember spending a lot of time failing to do this until I was shown the trick: spin the box and the ball bearings will magically end up in the holes.
So I thought I could build a larger version from a bunch of rusty wrenches, a little copper tubing, a threaded rod and a couple of ping pong balls.
Unfortunately I did not take pictures at each stage so I will try to show the finished toy with some detail pictures.
Basically I found several wrenches that looked like I could weld together and create the required shape. The required shape was kind of a trial and error. Too much slope and the balls would not stay in the holders. Too little and then one could achieve the result without having to spin.
I position a threaded rod in the center to keep the balls separated and also provide a way to open the whole thing up if it became necessary. The copper tubing acts as a handle and holds the balls in the track. I just epoxied the copper pieces together .
The new toy is actually a tad too big in that it is a little awkward to hold and spin at the same time but it can be done.
The first video shows how to do the old toy and the second shows the one I built.