The thing is very simply arranged and everything can be seen from the attached drawing. Mirrors (less than a centimeter in size) and everything else are attached to a bent stick from a construction set using plasticine, chewing gum, glue... The batteries last for several hours. Important - the angle between the motor shafts is close to 90 degrees, the mirrors on the shafts are crooked by 3-5-15 degrees. Result: a classic “Lissajous figure” (epi-/hypo-cycloid) is drawn on the wall or ceiling, with a certain number of petals, it rotates all the time, and the number of loops depends on the dissimilarity of the motors, and changes as the batteries are discharged. For children and those who have never seen an oscilloscope - “wow, how cool!” It comes together in half an hour. For the “advanced”: you can use the same batteries - just don’t forget that the pointer needs 4.5 volts, and for the motors - whatever you can get... For the “very advanced” - the pointer consumes ~40 milliamps, and how will you provide it with them? - it’s up to you (you just have to turn on the pointer and two motors in series and in parallel) from an external 5v source. Don't forget to place the device in a solid case and say that you bought it for $300 :)) Here are photographs (at different shutter speeds) of this laser light effect in action.
In this design you will need two small coolers from an old computer. We glue mirrors onto them with super glue. You ask - Where can I get mirrors?! - I will answer: in almost any office supply store they sell Chinese sharpeners with mirrors, and, accordingly, a laser pointer. Then everything is clear without words!
SECOND METHOD.
