MOTM

That looks really great! Make sure not to miss the first one too:
http://www.youtube.com/watch?v=PkRC_b6zpSM

John L Rice

> -----Original Message-----
> From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of
> Paul Schreiber
> Sent: Tuesday, October 12, 2010 7:44 AM
> To: MOTM List
> Subject: [motm] MOTM laser video
> 
> http://www.youtube.com/watch?v=3DFmXvFbWuc
> 
> Note that when Terry mentions "..the E350 is the filter..." this is
> referring to what is used to drive the galvos (the E350 is 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.
> 
> 
> 
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