engraving timing and power settings?
Posted: Sun Feb 12, 2012 10:33 am
Hi,
Since I will try to create all needed electronics myself (using microcontollers (multiple ones) ) I am preparing for what I will need.
The part to control steppers and even the part to control the laser on/off including PPI pulsing is not a problem.
But... I have a few things to think about laser engraving of pictures.
Dirktheeng wrote a little article about laser power and the fact that you get peak power in a single pulse at about 2 or 3 ms in the shot.
But what about engraving ?
If an engraving head travels a distance of for example 20cm (200mm or 1000 dots if we try to engrave 5dots/mm 127DPI)
That 20cm distance will be done at quite high speed, say for example at 500mm/sec
That means the laser only has 1/2500th of a second time per dot.
Thats 0.4ms for 1 dot.
How on earth are laser engravers doing this? Are they setting the power at 100% and then giving pulses for 0.4ms ? or do they use other tricks to be able to fire the laser that fast ?
I do recall from Dirktheeng's information that the laser does start shooting faster then those 2 to 3 ms, but will it allready shoot after 0.4ms ???
Is there anybody who has information about this ? Maybe those people who have emc2 configured to engraving could explain? I suppose they will have timings entered into their software?
My purpose is to recreate a controller in a very very very cheap way using Atmel AVR controllers (but not arduino, since I want to program them at much lower level to get very tight timing profiles)
Any info on these timings/settings would be very valuable to me.
Kind regards,
Bart
Since I will try to create all needed electronics myself (using microcontollers (multiple ones) ) I am preparing for what I will need.
The part to control steppers and even the part to control the laser on/off including PPI pulsing is not a problem.
But... I have a few things to think about laser engraving of pictures.
Dirktheeng wrote a little article about laser power and the fact that you get peak power in a single pulse at about 2 or 3 ms in the shot.
But what about engraving ?
If an engraving head travels a distance of for example 20cm (200mm or 1000 dots if we try to engrave 5dots/mm 127DPI)
That 20cm distance will be done at quite high speed, say for example at 500mm/sec
That means the laser only has 1/2500th of a second time per dot.
Thats 0.4ms for 1 dot.
How on earth are laser engravers doing this? Are they setting the power at 100% and then giving pulses for 0.4ms ? or do they use other tricks to be able to fire the laser that fast ?
I do recall from Dirktheeng's information that the laser does start shooting faster then those 2 to 3 ms, but will it allready shoot after 0.4ms ???
Is there anybody who has information about this ? Maybe those people who have emc2 configured to engraving could explain? I suppose they will have timings entered into their software?
My purpose is to recreate a controller in a very very very cheap way using Atmel AVR controllers (but not arduino, since I want to program them at much lower level to get very tight timing profiles)
Any info on these timings/settings would be very valuable to me.
Kind regards,
Bart