OMG 60W MOPA JPT Fiber Laser Coin Engraving Guide with Depth Map and Black Finish

I’m using an OMG 60W MOPA JPT fiber laser from Richard Zhang. (It’s an AWESOME MACHINE!!) I engraved a depth map image on the front side of the coin and a standard black laser engraving on the back side. — Engraved by Brett Progar

My settings used for this were:
150mm lens

Depth map:

• Speed: 2000 mm/sec
• PWR: 75%
• Frequency: 45 kHz
• Q-Pulse Width
• Line Interval: 0.0450 (564 DPI)
• Image mode: 3D Sliced
• Enable clean up pass: YES
• Angle Increment: 20

Clean up pass:

• Speed: 3000 mm/sec
• PWR: 20%
• Frequency: 100
• Q-Pulse Width: 200
• Line interval: 0.0450
• Clean up after # passes: Eight (8)

Laser engraving (back of coin):

• Speed: 120 mm/sec
• PWR: 60%
• Frequency: 50 kHz
• Q-pulse width: 200
• Line interval: 0.0250
• Lines per inch: 1016
• Scan Angle: 45
• passes: 2

Note: All depth map images and engraving are always done with Air assist to “blow” any debris out of the way and into the fume extractor. For more helpful techniques, check out our Laser Tips and Tricks guide.

Once the coin is engraved, it’s rubbed over a green Scotchbrite pad, then rinsed with soap & water. Once dry, the depth map engraving is cleaned with isopropyl alcohol to remove oils or contaminants. Finally, a few coats of “Brass Black” (or Amazon equivalent) are applied, and once dry, the coin is buffed again on the Scotchbrite pad to give a nice patina effect.