Mohammad:
For low cost fun to experiment with visible laseers you can easily make a galvo out of an old audio speaker. Use one that has a respectable amount of cone movement. The best method of mounting the mirror is to attach a thin metal or mylar strip across the speaker at the diameter so that it is flat to the plane of the speaker. Then you glue the mirror to this strip so that it is balanced perfectly. The idea is that this strip will act as a torsion bar. Then from one edge of the mirror on the side 90 degrees away from the support strip you affix a small push rod that has its opposite end glued to the speaker cone right by the voice coil (where the cone is strongest). A voltage that excites the speaker coil can now move the mirror which in turn can deflect a laser beam that is aimed at an angle at the mirror. With two such setups it is possible to fabricate a whole X & Y deflection system. It is easily possible to make small mirrors achieve movement speeds on the 100 to 500 Hz range with this kind of thing.

I first saw this scheme about 30 years ago when I went to see a laser light show. Afterwards I stayed to see the equipment that was used. The engineer of the operation had hand build all the laser aiming equipment using speakers. (it is a long time ago but I seem to recall the speakers were oval jobs about 3"x5" in size).
Mike