Making a DIY text laser projector

[NumLock]

The BLDC motor consists of three coils, which together make a stator. If one of the coils is connected to a positively-charged power source, and the other two are alternately connected to the negatively-charged source, the engine’s rotor would wobble.

Повысится ли точность изменения угла наклона зеркала если использовать шаговой электродвигатель?

[MedicusAmicus]

Depends on step drive frequency and minimum step angle. Any mechanical addons will corrupt accuracy.

[NumLock]

No any mechanical addons. Could be better idea is install step motor instead this BLDC motor?

[MedicusAmicus]

Only if step drive can move faster and more accurate than BLDC
Maybe HDD head positioning system? It moves really fast, but almost without any weight.

[iliasam]

HDD head positioning system can't work without position feedback so it is need complicated position sensor and position controlling parts.
Most of the steppers are not so fast but it possible that some of them can be suitable for that task.
Oscillation frequency is near 30 Hz.

[aabzel]

Have you tried to shine a laser projector into the water at night? For example, in a lake.

Then, if the scan is about 10-30 frames per second, you get a volume scanner under water.

It will be possible to find metal objects underwater.