On 6/20/2012 4:47 PM, AK wrote:
> The power you need is directly related to how fast you want to be able
> to mark the wood, and your final spot size on the wood.  You could get
> away with a few watts of IR light if you have good optical focus and
> didn't mind the marking process proceeding slowly (about 1-2 cm/sec).
> > From that figure, just multiply up the power by the speed increase you
> need.  From your mention of spinning mirrors, I'll assume that you're
> thinking of raster scanning the image.  To save time, many use vector
> scanning, as in the end the path length will be much shorter. For this
> you'll need galvos.

I have the laser assemblies and mirrors from a couple older HP laserjet=20
printers, they have the laser diode lined up with the spinning mirror so=20
that it outputs a single horizontal line. I was thinking of replacing=20
the diodes with higher power ones, and mounting one of these modules on=20
a sled that I have from an old scanner but turning it vertical so the=20
whole laser assembly moves top to bottom . The idea was to burn a line=20
horizontal, sled moves down vertical one notch, laser assembly burns=20
next horizontal line, sled moves down vertical, repeats until pattern is=20
finished.

I don't need this to be fast, it can take 2 hours to burn it and that=20
would be fine, I just want to avoid the process of standing over a=20
pattern and tracing it and  having to go back and forth between pattern=20
and wood to touch up missed spots or line, or spots I didn't press hard=20
enough, and it would be fun to try too.

>   For best focus across the plane of work, f-theta
> lenses are most often used.  This keeps the focal point of the beam at
> the same plane as it scans across the work, however it's not strictly
> necessary just for marking if you simply allow for a long enough throw
> from your galvos/mirros so the focal point doesn't stray too far from
> the plane of work.
>

Can you tell me what lenses would be best and what I should be looking=20
for. I did some work with them in college but that was decades ago when=20
everything was laser tubes and fairly bulky stuff, and  a lot higher=20
power than what I am considering. I really haven't done much with laser=20
diodes and mirrors.

Thanks
Mark

--=20
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