All the parts are designed so that no post-processing is needed (removing supports, sanding...) and only 3D printed parts are needed (except for the belts).
Happy printing

Another method of effecting the same result as No. 3, without guide-pulleys.
Other mechanisms from this same book
The official website of this book
I would really appreciate if you leave a like to this model so I can continue making many more 3D models like this one.
The author marked this model as their own original creation.