CNC Laser Engraving 8bit Shades of Grey 445nm

[conundrum]

Hi, maybe harvest the zone plate and lens from a broken PS3 optical block, could work.
Not sure how much power these can take but they ought to be OK if kept cool with flowing air..

Re. vibration, what about using an accelerometer to dampen out movements of the lenses using force feedback?
Burn with a "test" beam first and use a camera to fine tune the system then do full power burn.

-A

[deedee1814]

get this thing right and you have a very saleable personal crafting device that will turn the table top co2 cnc on its side

[JJWMACHINECO]

Thanks again for the information!

This project has been very rewarding for us in many ways. We have shared our experimentation freely for quite some time now hoping others would build there own systems and come up with new ideas and improvements to share also. This laser diode engraving process is less expensive as buying and using a CO2, so more of the hobbyist can build there own by just converting there CNC router over to a laser diode engraver. Our new Servo CNC router build will have the capabilities of both rotary spindle engraving and laser engraving which will allow us to combine the two processes into one project.

I did a first time experiment lasering engraving white cowhide leather and I had to leave the shop until it was finished because the fumes/smell was very overwhelming. The shading was not as defined like engraving on Birch Ply, but more experimentation with my program settings should improve the outcome. It was darker at first, but it had soot on it that I had wiped off. I'm also going to try different color leather in future to see how it effects the outcome. White may be reflecting to much of the 445nm laser's beam where the 405nm maybe a better option for laser engraving on it in the future.

Jeff

[deedee1814]

Yes for the white material s use the 405. They are much better bueners for even the half watt. versus a full watt..try doubling up the 405S to share a common path. i pictur running matirials througg a regular printer with a dual diod beam focused through the flying head and machin feeds material. continuusly

[JJWMACHINECO]

I tried the fuzzy back side of the white leather and it engraved much better. I used analog modulation with my 445nm this time. Since the leather was white, the engraving was closer to 8bit greyscale.

[JJWMACHINECO]

I finally got all the bugs worked out on my new dual 445nm laser engraver build on my servo CNC router. I was able to focus both the beams down to .004"-.005" and intersect them to the same focal point. It's 2 of DTR's Nichia 445nm 9mm LD's and the overall power of this one is very intense. I ran this engraving set to a 225 IPM feedrate, used a .004" pixel resolution (step over) and only ran it at half power. There were over 4 million lines of Gcode in this 9" X 7.2" engraving which took 1hr 35 mins to complete.

The MA3 analog shaft encoder is powered by the USB port and based on rotation, it's feeding 0-5 analog voltage to the modulation driver which is driven by my 4th axis servo motor. It takes 1/3 revolution of the servo motor to get a 0-5V out to the driver if full steps are used in Mach3 in the Motor Tuning for that axis. How I am able to change the overall output power of the LD's based on the 256 shades of the image, is change the steps to the servo. 12,000 steps is full, 6000 steps is half, ect.

In the Image to Gcode program I use, PicEngrave Pro 4 Plus Laser, I set the depth to -.0256" for that axis which varies the Lasers power 256 .0001" incremental levels, based on the 8bit shading of the image.

I recommend to everyone, if you build your own laser diode engravers, definitely use a Lasorb on them. I found my CNC servo machine's frame has some kind of charge/noise on it which took out the first two diodes as soon as I mounted it in the spindle clamp and turned it on.

Jeff

[JJWMACHINECO]

Laser engraved on Artist Canvas.

[LaserCo]

this was real interesting! thanks for sharing it with us

[milltools]

I am an enthusiast, but also a newbie now!
unlike others, we use a PENTAX SLR with FA 31mm/f1.8 lens, still study and looking for some more functions

[jtechphotonics]

It's 2 of DTR's Nichia 445nm 9mm LD's and the overall power of this one is very intense.

I recommend to everyone, if you build your own laser diode engravers, definitely use a Lasorb on them. I found my CNC servo machine's frame has some kind of charge/noise on it which took out the first two diodes as soon as I mounted it in the spindle clamp and turned it on.

Jeff - Nice work on this! I am working as well with the 445nm lasers and found a few to be having the esd issues mentioned above. I am using the older 5mm lasers, which do not have any esd protection in them. The new 9mm lasers are supposed to have the Lasorb built into them (according to the mfg datasheet). Were the "first two diodes" that succumbed to the esd events in your CNC the 9mm lasers from DTR ?

Jay