A light weight accelerometer was screwed to the Azul paddle face to monitor the forces before, during and after the impact. The output was recorded by a small, fast processor (Arduino Uno ESP-32) at a 1 kHz rate.
Accelerometer attached to paddle face
To the left is a slow motion video of the impact sequence. The blue egg crate foam and the green throw rug are the bumpers to slow the swinging paddle.
The accelerometer "hears" the air cannon fire at time zero. The ball reaches the paddle about 55 msec later and propels the paddle backwards. The paddle subsequently hits the two bumpers and slows.
The expanded graph to the right shows the ball impacting the paddle face with a 16 g force at times 54 and 55 msec. The actual force is much higher as the sensor maximum reading is 16 g.
After the ball leaves the paddle, the face vibrates at about a 300 Hz rate. The vibration is an indication of The "diving board effect" where all paddles naturally bend at the throat. The "trampoline effect" where the face vibrates like a drum will be be explored at a future article.
