One of my first projects with my OneFinity was to engrave plant ID tags for our home garden. I knew I wanted to used anodized aluminum as the tag material, but wasn’t sure how I was going to secure them to the CNC table for engraving. I considered various options, including creating a vacuum table, but finally decided to try a much simpler approach. After measuring several of the tags to check for variations in sizing, I used the CNC to route nine recesses in a piece of MDF slightly deeper than the tag thickness and slightly smaller than the tag outside dimensions. I then used a single edge razor blade to hand scrape the edges of the recesses to achieve a snug, friction fit with the tags. I also routed a small hole slightly deeper than the recess as a means to pry the engraved tags out of the fixture. I have to say I was skeptical as to whether the tags would stay in place during the engraving process, but after nearly 300 engraved tags, I have only had one casualty, and that was my fault for not making sure it was fully seated in the recess.
I am using the CNC-Aid spring loaded engraving bit holder (https://cnc-aid.com/) which allows for power engraving. I tried all the different engraving bits that came with it and settled on the one with the bluntest point and three cutting edges. I found similar ones on Amazon (https://www.amazon.com/dp/B08881PKBN?ref=ppx_yo2_dt_b_product_details&th=1) that seem to produce similar quality engravings. They are about 0.2” shorter than the ones that came from CNC-Aid, but the spring loaded holder still works with them. I have the Makita router on its highest speed (6).
I experimented with various fonts available in V-Carve Pro, and found for my application (smaller size letters), single line fonts work best. I tested half a dozen of the single line fonts and settled on “Futura Light 3L”. Some of the other available fonts looked a little better, but took over twice as long to engrave, so they were eliminated.
The anodized 1" x 2" dog tags came from The Ring Lord (https://theringlord.com/cart/shopdisplayproducts.asp?id=207&cat=Blanks+%26+Tags ) and cost about 20 cents each after shipping.
I am assuming I will eventually have to create a new holder as the edges of the recesses become worn and no longer hold the tags securely, but for now, it’s still working great.