To create raster jobs, use Graster:
you cannot use the " touch off" feature of EMC with a Graster job, it will not work and bad stuff will probably happen. ''Before starting a job, make sure the coordinate system is reset by going to'' Machine -> Zero Coordinate System -> P1 ''(the first option)''.
Graster is already installed on the laser PC you should use it there, if possible, because it is still a bit tricky to install.
To use it:
# Load the image onto the laser printer.<br/><pre>scp image.png firstname.lastname@example.org/
image.png</pre># SSH into the laser printer.# Run the script on your image.<br/><pre> ../ graster/graster.rb image.png</pre>
# The output results in three files: <br/> image.png.cut.ngc - A box cutout of the image. <br/> image.png.raster.gmask - The gmask file with laser instructions.<br/> '''image.png.raster.ngc''' - This is the main Gcode file that you want to load into the cutter.
===Advanced Graster info===
To run Graster yourself, '''you will need Ruby 1.9, not Ruby 1.8'''. At present, the version of 1.9 in the Debian/Ubuntu repository is '''very old''', do not install it. You will have to build Ruby 1.9 (or later) from source (http://www.ruby-lang.org/en/downloads/). You will also need to install RubyGems and a gem called rmagick (which is used to read image files). This is all a bit of a hassle and a simpler install method is planned for ''The Future''.
dpi: [500, 500]
on_range: [0.0, 0.5]
offset: [1.0, 1.0]
repeat: [1, 1]
tile_size: [3, 1]
tile_spacing: [0.125, 0.125]
'''dpi''': The resolution you want to draw the image at, in dots-per-inch. The laser's natural resolution is
500x500 so you should probably use that for best results. This means that 500 pixels in your image will be one inch on the laser. If you want it bigger, you should scale up the image in an image editing program that has good filtering or better yet, get a higher quality source image.
'''on_range''': The range of lightness values for which the laser will be on. Images are converted to greyscale with range 0..1 and tested against this range. Since the laser tends to darken things, the default is to laser dark pixels.
overshoot''': The stepper motors that move the laser can't start and stop instantly, they need time accelerate and decelerate. When drawing raster lines, you want to the laser to be moving at a constant speed from one end all the way to the other. We overshoot the end of the image so the X axis motor can change direction without affecting the burn. The default value seems to be enough for even the fastest speed.
offset''': The location of the bottom left corner of the image, relative to the bottom left corner of the laser table. This allows you to reposition the whole image. EMC has a similar feature in AXIS but you can't use that feature with Graster.
repeat''': Number of times to repeat the image in the X and Y directions. Yup, this lets you burn a whole batch of things instead of just one.
'''tile_size''': Size of repeated images
'''tile_spacing''': Gap between repeated images
feed''': Feed rate for rastering
'''cut_feed''': Feed rate for cutout
''corner_radius''': Corner radius of cutout, 0 for pointy corners
==== Graster Job Output/Running ====
Graster output consists of a cut G-code file (filename.cut.ngc), a raster G-code file (filename.raster.ngc) and a mask file (filename.raster.gmask).
* The cut file is a simple g-code sequence that just cuts out the outer perimeter rectangle of the image/job.
* The raster g-code file consists of a constant raster pattern covering the entire surface of the piece. It's normal for this to appear as a solid white box when loaded into AXIS (if you zoom in you will see the constant pattern).
* Once the raster job starts in AXIS, it executes the 'M101' g-code command, which is set up to launch the Graster Streamer. The g-code itself just tells the laser head to move back and forth over and over, and the Graster Streamer actually streams the bitmap data to it (via the mask file).
=== DXF Conversion Workflow ===
== Getting your files on the laser ==