Chebyshev Linkage Wheel3

Hexagon wheel. Variant of Chebyshev Linkage Wheel2. Resized version sample.
■ There exists the heel problem. heel/ toe digs the ground, so, please put on (= wear) the sandals. ex Japanese GETA (wikipedia). or Enjoy picture (wikipedia in Japanese site). ──── ⇒  ┬──┬ ■ Why bar ratio estimation failure? Value h is not fixed. WHY? WHY ④⑤⑥ exists ? ----- In figure, bullet Z● (color cyan) not just on the bullet C ● (color light blue) in except "a = 1" case. ------- this is bad!!! (if a=1, ④=⑤=⑥ h=√3 ) My equations are invalid? where is wrong (logic miss?) ? ■ Comparison of Number of edges. 4 edge: axis height =4, 360°distance=4*4; ratio 4 6 edge: axis height =√3, 360°distance=2*6; ratio 12/√3=4√3=6.928 (√3 is the length of 2, 2, 2 length equilateral triangle.) circle: axis height =r, 360°distance=2πr; ratio 2π=6.28 Please explain. 6.928 > 2π   ----- why?, efficient ? true?