Summary

The disk rotates continuously while the pen moves from side to side, using the principle of useless machines with a double ON-ON switch.
To make it easier to create different flowers, an ATtiny can be used to control the dc motors using analogRead and analogWrite.

Color the flowers and make a large flower bed at the wall. Nice job for a rainy afternoon.
https://youtu.be/alicKpRqjE8