Bagua tablet

In the picture you can see a simple device to cast hexagrams: an octagonal tablet (around 5cm wide) with one face displaying the eight trigram in the Fuxi Earlier Heaven arrangement and the other side with trigrams in the King Wen Later Heaven arrangement. Four lines, two on each side, are painted so that three yang (solid) lines and one yin (broken) lines are red.
To cast a hexagram the process is as follows:

1. Turn and flip the tablet without looking;
2. Stop and put a finger on one of the sides;
3. Draw the topmost line on that side. If it's red, it's a moving line;
4. Repeat steps 1-3 other five times drawing the hexgram from bottom to top

I built the one you see in the picture with laminated cardboard. You can see it is a little bit damaged in certain points due to the overuse (it has been my preferred method for more than a year). I believe it would be great if casted (or 3d printed) in metal.

Probabilities

Considering the two faces, the eight sides and the way the red lines are painted, the probabilities are the same as the Method of 16:

Prob(6) = ¹/₁₆
Prob(8) = ⁷/₁₆
Prob(7) = ⁵/₁₆
Prob(9) = ³/₁₆
Prob(yin) = Prob(yang) = ¹/₂