E350_laser2.mpg

YouTube via MOTMguy | October 12, 2010
follow-up to this post
"Another demo by Terry Ahrens showing laser galvos connected to a Synthesis Technology E350 Morphing Terrarium. Module info is here: http://www.analoguehaven.com/synthesi..."

via Paul Schreiber on the AH list:
"Note that when Terry mentions "..the E350 is the filter..." this is referring to what is used to drive the galvos (the E350 os a VCO in reality). Normally, envelope-detected audio is used as the "filter" and the galvos are swept by quadrature triangles (like a CRT raster sweep).

For those interested in replicating this setup: I will ask what galvos he is using and what they cost/where to buy. Note several important things:

a) in the US, this sort of laser projector CANNOT be used in public unless under very STRICT requirements.
b) professional "off the shelf" XY galvo pairs w/drive electronics and power supply can run $1500. The galvos can require 3A peak each, and the moving mass/inertia is large. The galvos are usually mounted on 1/4 in steel plates (called optical plates) and then inside a matte black steel box weighing 10kg/25lbs to keep vibration 'errors' to a minimum. The box keeps spurious laser deflections from "flying around the room" . These galvos are also very fast and very accurate: they can move to 30,000 individual positions per second (the mirrors usually have 45-55 degrees total travel) at 0.05 degree accuracy.

Thanks again to Terry Ahrens for setting this up and making the videos.

Paul S."