Laser engraver operation and software?

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10-31-2005, 05:38 AM
DennisCNC

Laser engraver operation and software?

I will be building a engraver/cutter very soon and one thing I can't get straight. What software would I use to control the engraving mode of the machine? The X axis will need to move back and forth quickly and the laser pulsed according to what needs to be engraved. Will Mach3 be able to do that? (I don't think so?)
From what I figure in needs to work like a laser printer, scanning the beam across. Or like most other printers, printing line after line.

Any help or advice or sites will be greatly appreciated and rewarded after the project is engraving things:)
10-31-2005, 08:02 PM
owhite

When you say you want the laser to engrave, it could mean two things.

In one case, you may simply want to set the power of the laser so it burns into the material. In this case the laser will operate at one power during the run. In another case, you may be talking about engraving the material at different levels of power during the run. This essentially achieves different "grey scales" of the part while its exposed to the beam.

This is an example of a grey scale picture on wood, done with a laser:
http://www.quagmirepuzzleboxes.com/Plaques/Fam_L.jpg

This is an example of engraved piece of metal done without grey scales:

http://www.cascadelaser.com/Graphics/markeng1b.jpg

Doing things without grey scales means you have some knob on your power supply, you set the knob to a certain level, and let the CNC software control when your laser is turned on and off. You should be able to do that with Mach3.

Doing things with grey scales requires that the power is adjusted real time as the part is moved underneath the laser. This could be done with 1) a commercial laser engraver that comes with software to handle grey scaling; 2) writing the programming software yourself; or 3) possibly, by bastardizing the software that is used on the commercial lasers that handle grey scales.

I dont think 3 would be very easy.

owen
10-31-2005, 08:34 PM
DennisCNC

First I want to start with no grey scale and latter work on it.
I guess your right about Mach (owen), I seen people engraving pictures with a V bit. This would be kind of the same as the bit has a very small point and you can control step over.

The bitmap to gcode converter software lets you set the depth of Z cut based on grey scale value so then I could use that data to vary laser power :idea:
10-21-2007, 10:19 PM
Pete Stenabaugh

Dennis, you wont be able to convert the g-code from an engraving file to work with a laser. The laser operates like a printer, and wants little dots.

For photoengraving software for a cnc router or mill go to www.vectric.com and look at the photovcarve software, but this wont work with a laser.

One of the better programs for laser engraving photos is photograv and it can be seen here: http://www.photograv.com/

You can also print to the laser directly out of Corel 11 or 12, but I havent tried it yet myself.

Pete
10-22-2007, 01:23 AM
mexico.redsail

Laser cutter/engraver software

Hello,
try a seach on ebay for "co2 laser software"
you will be surprized !!!
10-23-2007, 07:16 AM
ArturoV

Quote:

Originally Posted by Pete Stenabaugh

Dennis, you wont be able to convert the g-code from an engraving file to work with a laser. The laser operates like a printer, and wants little dots.

For photoengraving software for a cnc router or mill go to www.vectric.com and look at the photovcarve software, but this wont work with a laser.

One of the better programs for laser engraving photos is photograv and it can be seen here: http://www.photograv.com/

You can also print to the laser directly out of Corel 11 or 12, but I havent tried it yet myself.

Pete

Interesting Topic.

I guess now I know why I cant do grayscale images! Has anybody used grayscale images in a rabbit laser? Lasercut 5.0? I would really want to know how to make my laser read grayscale instead of just black/white.
thanks,
10-23-2007, 07:41 AM
turpija

Quote:

Originally Posted by owhite

When you say you want the laser to engrave, it could mean two things.

In one case, you may simply want to set the power of the laser so it burns into the material. In this case the laser will operate at one power during the run. In another case, you may be talking about engraving the material at different levels of power during the run. This essentially achieves different "grey scales" of the part while its exposed to the beam.

This is an example of a grey scale picture on wood, done with a laser:
http://www.quagmirepuzzleboxes.com/Plaques/Fam_L.jpg

This is an example of engraved piece of metal done without grey scales:

http://www.cascadelaser.com/Graphics/markeng1b.jpg

Doing things without grey scales means you have some knob on your power supply, you set the knob to a certain level, and let the CNC software control when your laser is turned on and off. You should be able to do that with Mach3.

Doing things with grey scales requires that the power is adjusted real time as the part is moved underneath the laser. This could be done with 1) a commercial laser engraver that comes with software to handle grey scaling; 2) writing the programming software yourself; or 3) possibly, by bastardizing the software that is used on the commercial lasers that handle grey scales.

I dont think 3 would be very easy.

owen

I don't think this is correct, and i assume you haven't work with laser engraver ...

At those two pictures you see exactly the same think but on one is text, and another is photograph (i know, i have good eye ;) ), but what is important for laser to make any of those you have to basically "draw" bitmap in "binary" or only black and white dots (pixels). Where there is black dot the laser mark it, and white it just "jumps over", it all depends of the software but this is how it works.
The other thing is, however, that a image appears to have shades (gray scale), but when you closeup a printed black and white image on ink jet printer, all you see are black dots - the same size, but, differently spaced, and thats what makes shades of black.

I can send you few images prepared for laser engraving, and few engraved examples and you'll see there are just lot of dots differently spaced, nothing more.
10-23-2007, 02:58 PM
mexico.redsail

Hello, most overseas laser engravers do not support grayscale to engrave, it must be a bitmap, if you want to test before engrave, convert to bitmap using halftome then print on an old dot matrix printer, this is how it will look laser engraved (without the banding)

Regards
10-23-2007, 08:17 PM
turpija

Quote:

Originally Posted by mexico.redsail

Hello, most overseas laser engravers do not support grayscale to engrave, it must be a bitmap, if you want to test before engrave, convert to bitmap using halftome then print on an old dot matrix printer, this is how it will look laser engraved (without the banding)

Regards

It is possible that better machines do indeed engrave in grayscale, but original question was to run a homemade machine and engrave photos, which are just fine engraved with "binary" bitmap.

Here is one close up picture engraved on laser, what do you think is it grayscale or halftone ?

http://img231.imageshack.us/img231/8607/img1325le3.jpg