so, the length of the "red piece" is ≈ 1.9 cm ≈ 0.019 meters; circumference C = 2πR; => the distance that the tip of the "red piece" passes ≈ 2 * 3.1415 * 0.019 ≈ 0.119377 ≈ 0.12 meters; Sound speed ≈ 340 m/s; 340 m/s / 0.12 meters ≈ 2833.(3) rps (revolutions per second) ≈ 170.000 rpm (revolutions per minute) - at such a speed, you need to turn the red piece in order for its very tip to overcome the speed of sound; The XL motor has a rotation speed of ≈ 220 rpm; 170000 / 220 = 772.(72) - this is how much it is necessary to increase the rotation speed from the motor to the red piece; at 1:19, the speeds of the input and output shafts are correlated as 1:729, which is ≈ 94.34% of the speed of sound; at 2:12, the speeds of the input and output shafts are correlated as 1:2187, which is almost three times the speed of sound, but then, the red piece is no longer spinning. In fact, it is likely that the speed of the tip of the red detail was not close to the speed of sound, since a lot of losses are due to the friction of the gears.
I wonder if the extremity of the red piece exceeds the speed of sound at such RPM.
so,
the length of the "red piece" is ≈ 1.9 cm ≈ 0.019 meters;
circumference C = 2πR;
=> the distance that the tip of the "red piece" passes ≈ 2 * 3.1415 * 0.019 ≈ 0.119377 ≈ 0.12 meters;
Sound speed ≈ 340 m/s;
340 m/s / 0.12 meters ≈ 2833.(3) rps (revolutions per second) ≈ 170.000 rpm (revolutions per minute) - at such a speed, you need to turn the red piece in order for its very tip to overcome the speed of sound;
The XL motor has a rotation speed of ≈ 220 rpm;
170000 / 220 = 772.(72) - this is how much it is necessary to increase the rotation speed from the motor to the red piece;
at 1:19, the speeds of the input and output shafts are correlated as 1:729, which is ≈ 94.34% of the speed of sound;
at 2:12, the speeds of the input and output shafts are correlated as 1:2187, which is almost three times the speed of sound, but then, the red piece is no longer spinning.
In fact, it is likely that the speed of the tip of the red detail was not close to the speed of sound, since a lot of losses are due to the friction of the gears.
I don’t understand what it’s for and what it can do. But interesting.