glass tube co2 with galvo head

[peterklos]

Hi
Has any one tried to interface a Chinese type co2 glass laser tube with a Galvo head , just thinking the laser trigger time slew rate may be too slow for a galvo but may be it could work at slower marking speeds ?
peter

[VDX]

... I've built a scanning head with high geared servos instead of galvos to use bigger mirrors than possible with galvo-heads - the actually equipped mirrors are 45x40x6mm ... but could be much bigger/heavier if needed.

Max. scanning speed in 300mm distance to the last mirror is around 1m/s ... no limit for slower scanning ;-)

Viktor

[peterklos]

... I've built a scanning head with high geared servos instead of galvos to use bigger mirrors than possible with galvo-heads - the actually equipped mirrors are 45x40x6mm ... but could be much bigger/heavier if needed.

Max. scanning speed in 300mm distance to the last mirror is around 1m/s ... no limit for slower scanning ;-)

Viktor

Hi Vikor
was that with a glass co2 tube for laser marking
what was the F thera lens you used for 300mm
peter

[sugeek]

You can use a co2 laser for marking with galvos using a F-theta lens for correction. I have been looking for a nice co2 f-theta lens for such a project but it seems there are more 1064/532nm available on the used market...

[mixedgas]

No reason the galvos cannot set there and wait for the laser. Ideally you use some other means of blanking the beam if the PSU is slow. Some commercial tubes reduce the current, some use pulsed RF to light the tube, others use mechanical or acoustic shutters. It varies all over the place.

Steve

[VDX]

Hi Peter,

Hi Vikor
was that with a glass co2 tube for laser marking
what was the F thera lens you used for 300mm
peter

... I'm using them without f-theta lens for 445nm-diodes or 1070nm fiberlasers ... only a focussing lens with 250mm focal distance before the first mirror, so the spot is roughly 150mm below the head.

With max. working areas of 60x60mm this is good enough -- for bigger scanning angles I'll add a motorized Z-axis for height-correction ... this will work only with the 'slow' servos, not with galvos ...

Viktor

[peterklos]

Hi
The problem with the glass Chinese Co2 tubes is that the slew rate to turn the beam on /off is too slow for galvo mirrors / beam to respond , as you mentioned acoustic shutter could be a solution, I am going to experiment with keeping the tube turned on at a fixed power and switching the beam via an acoustic shutter , I will collimate the beam and drive the galvo mirrors , dont know what sort of Beam or resolution as I want to use it for engraving
regards Peter