Laser Engraving

Wow - I've just come across this website forum where a guy has produced near photographic quality laser "burning" of wood using a 1W 445nm laser and a shaft encoder to allow analogue modulation of the laser - not fukky sure how yet - I'm investigating - but I was sufficiently impressed to get the link out.

www.photonlexicon.com/forums/showthread....Shades-of-Grey-445nm

I've attached an example of his work - its impressive and I can see many uses in my guitar builds - easy ones would be mimicing flame maple and quilt maple patterns in the top veneers.

Sorry guys - didn't mean to put "not fu**y sure..." meant to be "not fully sure..." - slip of the fingers - don't flame me.

Micromet wrote: Wow - I've just come across this website forum where a guy has produced near photographic quality laser "burning" of wood using a 1W 445nm laser and a shaft encoder to allow analogue modulation of the laser - not fully sure how yet

I have read the article, and the answer is "he is doing it in the most stupid way possible"

He is taking the output from something like image-to-Gcode (which is built-in the LinuxCNC, by the way, just try opening a JPG in Axis instead of a G-code file). The then what would normally be a Z-axis move is actually turning a stepper motor that turns a bit of hardware that varies the laser power.

In a LinuxCNC setup you would instead take the Z-axis command signal in HAL direct to a PWMgen and take the PWM output to the laser diode.

Hi Andy,
Thanks for the info - again. I didn't know anything about the Image-to-Gcode ability in linuxcnc - have been using Gcodetools in Inkscape with mixed success. Also didn't know about the PVMgen option in linuxcnc. There are so many alleyways in linuxcnc.
Is there an example file somewhere that I can look at to see the protocol and typical text - I don't want to blow up my expensive laser diode.

Micromet wrote: Is there an example file somewhere that I can look at to see the protocol and typical text - I don't want to blow up my expensive laser diode.

Does the diode want PWM or does it need analogue voltage?

what diode driver are you using most use a pwm input , it's the driver that protects the diode
as it needs to be constant current , NOT constant voltage , so so long as it's meant for powering lasers
your ok . and it's set up of course to start with