Greetings everyone!
I want to share some observations on engraving black anodized aluminum. It took quite a while to solve the issue with the laser focus spot shape. I used three different NEJE lasers: E30, A40640, and E30. The problem with the E80 laser was the presence of a double laser spot (spots of different intensities, with a spot size of 140um x 100um), which prevented increasing the resolution of the graphics. The same phenomenon appeared on the A40640 laser, along with a tail. Then I bought a new E30, which was advertised as having very good spot quality. The E30 is quite good, and I added an extra quartz plano-convex lens to reduce the focal length and the spot size (the spot was initially 57um x 50um), which ultimately resulted in 35um x 35um. Make sure to verify and draw your own conclusions.
Here are some samples in different resolutions (zoom in to check focus point, all the photos are unprocessed, black anodized credit card base-86x54mm):
- Neje E80, 300 DPI
https://photos.app.goo.gl/fLFyYazfdbLdCCT9A - Neje A40640, 450 DPI
https://photos.app.goo.gl/cPJVMDKhdbHekTms6 - Neje A40640, 600 DPI
https://photos.app.goo.gl/aT68oconHoVp7gUY6 - Neje E30 (+Plano convex lens), 750 DPI
https://photos.app.goo.gl/hM1M8nfdRtBmdtSbA - Eye of the fly (extreme macro), Neje E30 (+Plano convex lens), 750 DPI
https://photos.app.goo.gl/YaMrR36oKSdTt2Uu9 - Eyes of the spider (extreme macro), Neje E30 (+Plano convex lens), 750 DPI
https://photos.app.goo.gl/ZsQBxXnGCafSaT4U6 - Test chart, Neje E30 (+Plano convex lens), 750 DPI
https://photos.app.goo.gl/cg86Kvayi69tNdA59
Everything is possible if you waste enough time!
Best regards!