I finally finished a project I’ve been working on for a couple months now, creating a template for POW/MIA/KIA/memorial bracelets for fallen servicemembers and classmates.
First part of the project was done with the CNC, carving out channels from MDF to make it easy to precisely drop the bracelet blanks in place for a large-scale production run. It’s set up for 1/2" x 7" blanks and can hold 54 of them. It screws into the CNC workplate with recessed screws and can be removed in just a couple minutes so I can do other projects.
Second part of the project was setting up the laser with the bracelet outlines and then doing the text and graphics within them. I did it ALL in Luban. I know y’all are going to say that Lightburn is way easier and I’m sure you’re right, but once I got on a roll with Luban, it was pretty quick. The weirdest part was trying to get the coordinate system to align so I could make use of the full 400 x 400mm area. Through trial and error, I was able to get it figured out, but it actually ends up printing down in the X, -Y quadrant (i.e. BELOW the usual workspace). If it ain’t broken, I’m not going to try to fix it until it is… but it’s definitely strange. I just used the main workspace for my notes on settings as I built out the template… just like the rectangular boxes that show the bracelet outlines, you just don’t create a process to burn the notes or the rectangles when you go to actually make the bracelets.
After burning dozens of test bracelets, I found I got the best results with the following settings.
TEXT (ALL COLORS):
----Baskerville Old Face (Regular)
----Name line: 4.2mm H (if no J, (), Q, comma, or other “dangly”), 4.8mm H otherwise
----Second line: 3.5mm H with “dangly”, 2.8mm without
----“Vector Line Filled” preset
----.02 mm fill interval
----2000 mm / min working and jog speed
---- 100% power (NOT constant power)
IMAGES (UNLESS OTHERWISE SPECIFIED):
----Greyscale, NO conversion algorithm, default settings (50/50/255)
----Dot fill
----0.05mm interval
----5ms dwell time
----100% power (NOT constant power)
FA, ADA, MI, IN:
----0.03mm interval
AV:
----0.01mm interval
Main rows: 181.6mm center-to-center, 6.5mm gap
Main columns: 15.8mm center-to-center, 5.8mm gap
Side rows: 181.6mm center-to-center, 6.5mm gap
99.1mm side row c-c to main row c-c, 6.55mm gap
All project files here:
Memorial_Bracelet_Snapmaker_files.zip (2.1 MB)
One of the challenges I ran into was how to get good, DARK markings on the bare aluminum or the lighter (i.e. gold) anodized aluminum. I tried several of the sprays designed for this purpose with limited efficacy. Tough to get an even coating, messy, expensive, and time consuming. As it turns out, though, the protective film that comes on the blanks I bought (for the bare) or a simple piece of cellophane tape (for the gold) results in a nice dark engraving mark that doesn’t even come off with acetone or rubbing alcohol. I don’t know if it’s designed to work that way, but it definitely works, so I’m not going to look a gift horse in the mouth.
Another challenge was that, as I cut-copy-pasted one successful design into subsequent blanks and went to change the names/dates/etc, the text box would do some weird auto-resizing despite being set to a certain point font. I found that by setting the vertical height back to a standard height, everything would look uniform regardless of how many letters were in the line of text. I think it had to do with the font that I chose… with certain characters (i.e. Q, J, a comma, a parenthesis, etc.) going below the base line upon which the letters sit, it made the overall text appear to be a different size because the text BOX itself would try to remain constant. Once I figured that out, it was easy to determine two different text box heights that would keep things uniform.
The resolution of the 2W IR laser is incredible. You can see the individual feathers on the Aviation branch insignia and (even more impressive) read the mottos on the scrolls of the class and academy crests… which is about 0.25mm high, if that. I’ll post the files and settings here to save my fellow makers the trouble of trial and error for similar projects of your own.
-Jon
