Wheel vs. pendulum...

[iacob alex]

.....or two pathways , perceptions to a possible self-running gravity simple machine ...on the cover of a book , if you take a deeper insight on the cover of a book , at :
  http://books.veljkomilkovic.com/gravitational-machines.html
If the instinct is the "nose" of our mind , the first step of knowledge is nothing more than the perception of an elementary "something" / image to follow, come after...
  ...to realize a " pendular effect" ( continuous / cyclic fall of an inverted pendulum !).
          Al_ex

[Mayo]

Here is the book cover image you mentioned.
It is really good visualization.

[iacob alex]

.....or you can move your body "as a wheel" , but simply playing as an inverted pendulum :
     www.cor-kinetic.com/wp-content/uploads/2011/12/picture-1.png
     An inverted pendulum is the symbol of unbalance and the "key" to change the potential into kinetic energy  (work & transport ).
         Al_ex

[iacob alex]

.....or a wheels & pendulum chariot , at : https://m.youtube.com/watch?v=QS0rouI9Rh0

      Al_ex

[lumen]

@Alex
It might be possible to use your inverted pendulum in a new way.
Have a look at my latest video. https://youtu.be/l5i2M-_g2sM