A). Go from straight parts to curved ones, from flat surfaces to spherical ones, from cube and parallelepiped parts to ball structures;
B). Use rollers, balls, spirals (small parts);
C). Go from linear motion to a rotary one, use centrifugal force.
The opposite:
0) Use only objects with straight angles;
A) Use straight lines and flat surfaces;
B) Use angled small particles;
C) Use linear motion, the more precise the better.
This is the Method 9 [14] | Index