I think I’m getting the hang of etching tiles. I made this post to help others, but I’m still learning myself. In hopes of helping others, I listed my explicit steps below as I was confused about how to do real world stuff (see Confused about how to use laser with real items (wallets, iPhone cases, etc))
I decided to switch to Lightburn instead of the very limited Luban software. Main advantage with Lightburn is you can easily fine tune different aspects of the burn, and it won’t add more image processing if you already optimized the image with another application. It also has way better dithering options if you just import a graphic. I set it up for my A350 as in the post here: https://forum.lightburnsoftware.com/t/snapmaker-2-0-a350-setup-guide/21540 - basically set your bed parameters, then edit the machine settings for baud rate (115,200),s-value max 255, and enable Z-axis control (Edit>Device Settings>Basic Settings) - the post has screenshots. I really have no experience with Lightburn aside from what I show here, and I welcome any other insights!
Note: I’ve just been using Lightburn to export gcode to the Snapmaker via USB - these control settings are meant for direct connection to the Snapmaker, but I haven’t tried that yet and you can do all I list below without configuring the baud rate etc). I’d imagine direct connect would fix the trace outline function that doesn’t seem to work if I’m using the gcode file (see below).
Other things to note on Luban setup: set the speed units to mm/min in the preferences as this is the usual notation for diode lasers like ours.
Decide how you want to do your tile: I found 2 methods:
Black spray paint over the white tile, then use the laser to burn off the paint to reveal the tile below. This makes for a rich black image and you can even use another color below (eg first a layer of red paint, let dry then cover with black spray paint). The disadvantage is this is more delicate as the paint can scratch off. You can clear coat to get around this problem. One tip I think would have made my first tiles look better: before clear coating, I should have gently wiped off the surface - I suspect my tiles came out quite dark because there is some residue from the burning process(the image is actually a little hard to see depending on the angle and light). I used 800 mm/min, 100% power. In Luban I specified 5 ms/dot. I didn’t see a similar setting in Lightburn.
Norton method: this has the distinct advantage of being permanently etched into the tile glaze and cannot be scraped off. Disadvantage is the blacks aren’t very deep, more a dark grey. No surface treatment needed afterward unless you want a more uniform gloss (and it enhances the blacks a bit). The method involves a light coat of flat white spray paint over the tile, then etch the image (I found 900 mm/min, 90% power worked well for the 1.6 W Snapmaker head), and then finish by removing all white paint with acetone.
Step by step instructions:
- Clean tile with acetone - important as many tiles come with a film on top from manufacturing
- Spray light coat of flat white spraypaint (Norton method, permanent etching) or black spraypaint (much more delicate finish, needs clearcoat protection, much richer blacks, option for a second color underneath).
- Import image into Lightburn
Scale image size to tile size (note mm/inch button in toolbar)
2. Set Lightburn parameters - open the layer menu for your selected image
- Norton method: Speed: 900 mm/min Max power: 90%
- Black paint removal method: speed 800 mm/min, max power 100%
- If burning to remove the black paint to reveal the tile below, make sure you choose "negative image"
- Enable Output, Disable Air Assist
- Line interval 0.1mm, 254 dpi (or Enable Passthrough if using image to set DPI value - I didn’t try this myself yet)
- Scan angle, Z offset =0
- Image mode:
- Choose “Threshold” if image dithered outside of Lightburn
- Choose “Halftone”for shading images imported without modification
50 cells per inch = default, use higher for finer detail/dots
- No of passes = 1
- Laser section: set your origin according to how you want to place the image
- If setting laser Origin on Snapmaker to the lower left corner of the workpiece: Snapmaker will start burning immediately from position set. On the Snapmaker (see section below) use Automatic mode, then set origin to lower left corner
Start From: User origin
Job Origin: Lower left corner
- If setting laser Origin on Snapmaker to the center of the workpiece: Snapmaker will move from center origin to lower left of project. On the Snapmaker (see section below) use Automatic mode, then set origin to center of workpiece
Start From: User origin
Job origin: Middle
- Export code but save as .nc file
On the Snapmaker
- Start the project by opening the file from USB
- Choose automatic mode (assuming you already calibrated your laser using the built in Snapmaker process)
- Set the material thickness (eg my tile was 6.9 mm). The Snapmaker will then add the calibrated laser focal distance to this value to set the z-axis height above your workpiece.
- Move the laser head to the origin you chose in step 3 above - either the center of the workpiece or lower left corner. The Snapmaker laser will turn on with low output to help you see where it is aiming.
- Press the “set origin” button (it’s critical to do this or the job won’t be properly aligned)
- Note: for some reason, if using Lightburn code files, the run border function does NOT seem to accurately show the cut profile - it seems way off, but the file burns properly if you set the origin properly
- Put on laser goggles!
- Hit start
- Norton method: Wipe off all paint with acetone, clear coat if desired
- Black paint method: gently wipe off residue, coat initially with very light clear coat, allow to dry then apply heavier coat