Which is better for a DIY liquid sky effect: spinning polygon mirrors, or a galvo?

[PatrickJS]

Working on my first DIY laser project: an RGV, color-shifting, liquid sky effect.

Given that I'm not trying to make any fancy 2D pictures, should I still follow the design of your basic DIY RGV projector, minus the y-axis galvo, or is it better to replace the galvo with a spinning mirror from an old laser printer? What are the pros and cons of the two approaches for getting the laser to scan?

 

[lasersbee]

I use optics.... Cheaper and easier to assemble.

Jerry

 

[Benm]

If you just want to sweep the beam across a plane using a rotating mirror would be much easier compared to setting up a full galvo system.

But as laserbee pointed out that can also be done without any moving parts using a grating or something similar.

 

[LSRFAQ]

Rotating mirrors give you very large angle scans with a fixed angle. This spreads the energy out a lot, which can mean needing more laser power. Also they tend to have a very narrow scan rate range, which gets boring.

Steve