Laser engraving


#1

I am having trouble engraving. I can engrave text, but not anything with grey scale. Is there a specific format for grey scale image? Is there a place to download good images that would laser well?
Every time I try to image something it looks really nice, but when I upload it to the part where it goes to image the object to the printer it looks like a black blob, but on the first part where you preview it, it looks nice. Am I missing something? Can I get a sample of the iron man or tiger emailed to me? davidb@technewszone.com


#2

Remember that Laser Engraving is like Old School printing: It’s not capable of Grey Scale. You may need to convert images to HalfTones for printing. IE: various sizes of dot instead of “shades of grey” dots.


#3

Maybe you should try leveling down the laser power.
Set the focus on the object and try levels below 50% first.
If it is not dark enough you can give it a second run.


#4

Hi, @TechnewszoneAll you need is an image, then use Snapmakerjs to convert it to gresyscale then generate GCode to do laser engraving.

About the Snapmaker Showcase category Check this out.

Tips:

  1. Please be sure you choose greyscale mode. https://manual.snapmaker.com/laser_engraving/generate_g-code_using_snapmakerjs.html
  2. Follow this to focus laser https://manual.snapmaker.com/laser_engraving/set_the_laser_power_and_choose_a_way_to_engrave.html
  3. Last but not least, try different wood

@poundteam We implement Dithering algorithm to generate Gcode. All you need is an image. These two images have been tested.

samurai


#5

@whimsycwd thanks for the note. I wonder what these look like after they’ve been burned?


#6

greyscale works - but it’s slow. This is engraved on bamboo coasters.

It looks even better on leather coasters.

get the focus right, set your white clip, I used FloyedSteinburg with a dwell time of 20ms, a work speed of 800mm/minute, and burned with a laser power setting of 100% for bamboo and 70% for leather.

here is the result and the original greyscale.


#7

Excellent post. Thanks for that. How did you acquire the raw coaster material? Pre-cut at some online retailer, or did you cut the circles with cnc?


#8

I got them from Amazon. The bamboo ones are from Amazon, sold in a 6 pack (though the round ones are all gone, and now they have square ones). They weren’t very flat, and after I engraved a bunch, I did a drink test and was unhappy with the likelihood of spilling a drink. So I switched to leather.

The leather ones are Tandy 3.5" leather rounders. A 25 pack was $34.95 with free Prime shipping.

David


#9

If my laser may be defective, can it be replaced? it does not laser, and it does not move in the z direction. The printer 3d prints well…


#10

when layering, it will not move in the Z direction - the Z height is established during the focus stage of setup.

I had a problem with mine not focusing, the focus dot should be <0.2-0.5mm in size - ridiculously tiny - about the size of a period in 8 point text.

I had to manually turn my focus on the module counter clockwise about 1/8 turn to get it aligned (which required a bit of effort), then use the setup in SnapmakerJS to get it precise. I go up and down 1mm in Z height during focus and stop when the dot is the smallest. It was “good enough” there that I did not have to change the height less than 1mm. (if you look close, you can see the focus dot - in the photo it looks HUGE).


#11

Also don’t Forget to set and save the higher laser power after focusing - I also did have my Problems at my first try.


#12

Haha, it surprises me that you found the size of the dot when the laser is focused. Actually less than 0.5 mm is enough. I will upload the calibration card later so that you can print it out and help you find the focus.


#13

Here is the calibration card I talked about:
Calibration Card


#14

could i print out the card bigger so i can see the dot…? :wink:

actually, all jokes aside, perhaps a ring around the dot for us old farts with dim vision…

william…


#15

@Rainie

Can you make this calibration card available for downloading and printing?

Have a great week and a happy Chinese New Year to all of you

Doug


#16

Hi @william.o.yates and @Rainie @Noah

I would also appreciate knowing what the optimum height above the project that the laser head should be placed. With the focus ring turned all the way in, the bottom of the laser lens head is about 39mm above the project and i need a minimum of 80% power. Lower power gets no results.

Keep having fun

Doug


#17

Hi Doug,

Here is the calibration card of PDF file for downloading (Forum can’t upload PDF file so I compress it).

Calibration-Card-output.pdf.zip (814.0 KB)

The optimum height is quiet different when the laser module is produced. Because it’s mainly depends on the focus, which may change by rotating. Just move the Z axis to make it as small as possible, then it will be a best height.


I can only Print with Raft!
#18

Hi, just been trying out the laser but I have a question…is there a way to move the image so the origin point would be in the centre rather than the bottom left as this would make it much easier to position the laser correctly.


#19

Hi @elminster

I am a newbie and I find the origin also referred to as the Toohead position is fine where it is. I turn on the Laser Focus, move the beam to what would be the lower left position, Click on Run Boundary and when it looks good, I click on Set Origin then I start the print. To me having the origin in the centre would be more difficult to setup,

Hope this helps

Doug


#20

Thanks for the advice, I just thought that being able to work from the centre as an option could help. Weirdly enough in the cnc tutorial the image is centred on the origin point when loaded into the software.