I launched the new YouTube Channel “Akiyuki Brick Lab” .
I uploaded following two videos.
Lego: An attempt to distinguish soccer and basketballs by their rolling traits
I try to sort the two kinds of LEGO balls, soccer balls and basketballs, without a light sensor.
Rolling-down speeds of the balls depend on their groove features.
Lego: Which is the strongest axle? (torsional stiffness test)
I compared the torsional stiffness of five Lego axle samples.