Jewelers Benchpin Forums

The following testing was done, using a rotary, on a 14 karat white gold mens ring that was approximately 2.21mm thick and 6.57mm wide where it was engraved. Using the following settings I was able to get insanely fine details and clear legibility with text. Though I could get a clear engraving of text characters that are less than 1mm in size I opted to do the entire engraving at 1mm height. To be clear, I am using an image of text, not text, for this test job.

Image [SVG/PNG image with a solid black image on a transparent background]
Engrave
Fiber IR laser type
150 microns dot duration
75 % power range
1,200 dpi
1 pass
Floyd bitmap mode
Bi-Directional engraving mode
30 kHz

One Pass does a great job, but I found I like a little more depth. When I would run a single job with multiple passes it would create too many burrs or "slag". To remedy this I found that if I run a single job with one pass, then process the exact same job two more times, I get a better depth with less burrs or slag. I still use a brass brush to clean off the scorched metal, and if I were at the shop I would lightly hit the inside ring at the polishing machine, but I am not sure it is really necessary as the burrs are not sharp and may provide a little more longevity if anything.

All close-up examinations were done at 10X magnification (with a loupe).

I will need to update or reply in this thread with Text settings on 14 karat white gold.

The following testing was done, using a rotary, on a 14 karat white gold mens ring that was approximately 2.21mm thick and 6.57mm wide (actually it varies and I did not measure it) where it was engraved. Using the following settings I was able to get fine details and very clear legibility with text. Though I could get a clear engraving of text characters that are less than 1mm in size I opted to do the entire engraving at 1.75mm height (it is actually width because I turned the text 90 degrees to run along the inside of the ring). To be clear, I am using typed text, not an image, for this test job.

Text [Chopin Script]
Engrave
Fiber IR laser type
70 % power range
400 mm/s
3 pass
Bi-Directional engraving mode
30 kHz

One Pass still does a great job, but I want more depth. Two passes was crispy clear. Three passes started to get fuzzy but had a better depth. By lowering the power down to 70% I did not have as much of an issue with burrs or slag. I had also increased the speed from my initial tests of 200 mm/s to 400 mm/s. I still use a brass brush for clean up.

I will definitely be fine-tuning this, but this is a great starting point.

Something to be noted is that the current software and hardware have different settings available when engraving a flat object versus a round object on the rotary. This means there are a total of four settings for every metal (flat image, flat text, rotary image, rotary text).

All close-up examinations were done at 10X magnification (with a loupe and a microscope).

For the inside ring engraving, after several more tests, I am leaning towards running TWO JOBS of the following (run one job, then reprocess it without moving anything):

Text [Centaur]
Engrave
Fiber IR laser type
70 % power range
400 mm/s
2 pass
Bi-Directional engraving mode
30 kHz

Running this job two times will end up with four total passes. In my testing, this yielded better results than running a single job with 4 passes. Results may vary, especially depending on alloys and cast quality.

I have actually run out of 14kw rings to use for testing. I will need to go in and buff these out or find more test rings.