... with mirror-scanning adding optics and expanding the beam to diameters >5mm is a bit complex.
After cracking several mirrors with up to 15x15x1mm square-sizes, mounted on the cheapish galvo-scanners, I'm changing to 40x40x6mm big mirrors and servo-motors instead of the galvos for moving them.
With the smaller mirrors on the galvos the max. usable energy of the laser was around 10Watts in CW mode until they cracked or evaporated - with the 40x40mm mirrors I've managed to run above 50Watts in CW mode for some minutes without damaging the mirrors ... but heated the quartz-glass body to above 80degC!
With below 15Watts and fast scanning galvos I had to hit a spot on the target surface up to 30x to remove the material ... with the higher usable energy with the 40x40 mirrors this counts will be drastically reduced, so even with the slower servos (only around 1m/s engraving speed compared to above 20m/s with the galvos) I can mark/engrave fast enough ... and much faster than with my CNC-mill, what's engraving with max. 150mm/s.
Attached is an image of my last preassembled setup with the servo-motors and the drivers (bottom left), but without the controller ... wrecked it last week, so have to gather a new one 8-)
[attachment 31261 Stellprobe2.jpg]
After cracking several mirrors with up to 15x15x1mm square-sizes, mounted on the cheapish galvo-scanners, I'm changing to 40x40x6mm big mirrors and servo-motors instead of the galvos for moving them.
With the smaller mirrors on the galvos the max. usable energy of the laser was around 10Watts in CW mode until they cracked or evaporated - with the 40x40mm mirrors I've managed to run above 50Watts in CW mode for some minutes without damaging the mirrors ... but heated the quartz-glass body to above 80degC!
With below 15Watts and fast scanning galvos I had to hit a spot on the target surface up to 30x to remove the material ... with the higher usable energy with the 40x40 mirrors this counts will be drastically reduced, so even with the slower servos (only around 1m/s engraving speed compared to above 20m/s with the galvos) I can mark/engrave fast enough ... and much faster than with my CNC-mill, what's engraving with max. 150mm/s.
Attached is an image of my last preassembled setup with the servo-motors and the drivers (bottom left), but without the controller ... wrecked it last week, so have to gather a new one 8-)
[attachment 31261 Stellprobe2.jpg]