Gears investigation: Banbao Lego crawling insect

Completion date: May 4, 2020

Actually this thing looks like a crawling insect to me than a walking robot.

1. This is 8:40 gear in terms of speed
2. The 40-teeth gear has two roles, one as speed slowing mechanism, and also a revolver to bring axle on a circular motion.
3. The axle going in circle has an interesting effect. When the axle “draws” a circle, if you analyse the horizontal motion only on a horizontal line, it is actually not a uniform speed from left to right. It would be slow (left), faster (middle), slow (right). The same idea goes vertically: slow (top), faster (middle), slow (bottom).
4. I couldn’t be sure, but I think the bar that is on this axle (grey middle leg) is having this kind of slow-fast-slow-slow-fast-slow rhythm too.
5. The jerking motion of the grey leg looks like walking, because the leg picks up off the ground before landing on ground again.
6. The grey legs are directly attached to the 40-teeth, so this is 1st degree motion. While the other 4 blue legs touching the ground are pivoting/turning on a 2nd degree motion. The blue legs moves in 1/8 of a circle, so the distance to the ground is small.

My afterthought on this, is that this is a lot harder to know exactly what is going on with the leg motion. It is the angle and length and the pivoting point that determine how the legs go in a certain way. This part for me, it will be trial-and-error if I put together something on my own.

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