Zennedine finds a way to use our coils, so I tried to make a first box to check if it will not collapse. I made this and I checked if the marble flip or not, and it works.
When we begin our project, we ship some coils, the 74458303 but in a short time, we cannot ship enough coils for the project. So I tried with the same configuration to use the 74458304 coils, and it works, even if there were more edge effect (the nearest coils flip sometimes). With these coils, we need only 0.59A instead of 0.80A.
I also made the same tests with the SDR1307A-102K which are smaller coils, but there is still enough available. These coils flip the marbles for 1.35A.
Now, I will try to make two other boxes. One with more space between the marbles and the wood. Currently, to avoid friction, we need to have a hole in the wood of a diameter of 11mm, which is bigger than the diameter of the marbles. But if you reverse the box, marbles fall. The other will be for the test of the smaller coils