Laser loses power

[X07gavrp]

Does any one know how long you can run a 6w blue laser for? Its hooked up to my CNC, I use it for engraving in 8shades , halfway through it loses power?

[norty303]

Is it a single diode running at 6W? I would think it might be for engraving. If so, its more than likely reducing due to heat (potentially overdriven but I don't know what pulse rates you're using). Either sort out the heatsinking or reduce the power.
Knocking the power down a bit might mean you get average higher powers for longer.

[VDX]

... can you measure the current and housing temperature?

If you'll overdrive the diode, it won't last for long

Viktor

[X07gavrp]

Hey, thank you for replying much appreciated, yeah its single diode, I havnt sorted out heatsink asyet ,only just hooked it up to my CNC took me awhile to get it connected after trial and error, it never got to hot when I ran it from pwm output from motion controller but was way to slow due to s command on maxh3 when changing frequency, so I I hooked it up to A axis output my laser is 0-5v so I got 10kohm resister split between AS and dc5v like what I did with pwm output but now laser is getn bit hot not much it reaches 30 degrees never over that, but dies right down in power still burns dark spots on image but dosnt shade the rest of image?, I use between 1000-1001mm to control laser intensity been working pretty well up until now, I'm new to this so don't if I'm right or wrong some constructive criticism would be great.

[VDX]

... regulating the diode with voltage is not good - you'll need a current-regulator to hold the current strictly below 4.8A max!

If the housing gets warm, this is not good either - you'll need a good thermal mass or active cooling to hold the housing below 30degC.

Even short exceeding of the max. current or voltage values will degrade the diode seriously!

Viktor

[X07gavrp]

Shit im using 4.8a from stepper motor drive

[X07gavrp]

Vdx what cooling you recomend , fan? Also do younthink c02 laser add is better to do to my cnc or can i get much stronger laser diode to engrave metals and cut with aslong as engrave

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Where can buybthis?

[X07gavrp]

Sorry for all question , people like you have so much knowledge and i would love to learn so i can get to same level

[VDX]

... I'm clamping my diodes to big heat-sinks, so no need for fans or active cooling - see here the first image - http://forums.reprap.org/read.php?414,610132

Here you can find some basic infos - http://reprap.org/wiki/Laser_Cutter_Notes

And here is a bunch of related threads in English - http://forums.reprap.org/list.php?133

Viktor