Short guide to the use of laser cutting machines/Use of Inkscape for Laser Cutting

In this sections of the book will be described how to use Inkscape software to create patterns to be used in laser cutting machines.

Introduction
Inkscape is a free and open-source software for to drawing, design and edition of vector graphics, this make it ideal to create images or design and use them to cut materials using laser cutting machines.

Current Inkscape version is 1.3.2, it can be downloaded from the Inscape webside, it also includes a free portable version (1.2.1) that can be downloaded from its website.

Create a new file
Open Inkscape and start working in the project... the color options and unit measures can be changed at any time.

Left menues
To create lines, draw images, create shapes or designs will be used Inkscape left menu, the most used options are: Pen, pencil, text, shapes tools, etc. with them will be created lines, draw other images, make shapes such as rectangles, circles, etc. Or create new designs.

Left menues
The right menues are the following:

Fill and stroke

 * Fill: In this option the colors can be changed from CYMK to RGB, for cutting change the RGBA number to FF0000 (red).


 * Stroke and paint: In order to see the lines and objects choose one of the strokes. Choose the first option for flat colors. Gradient strokes are not uniform and can be used for raster or edging.


 * Stroke stile: In this option can be changed the stroke width, change the units to points and use 0.72 points, this the same than use 0.001" (inches or 0.254 mm, and indicates the laser cutting machine that is a cutting line.

Layers
It allow to choose all the layers in the image, each time a line or object is drawn (with color or not) a new layer is created.

If all the layers are selected, can be grouped as one image.

Export
In this menu can be choose the details of the image: size, format, etc. and export the project as a image, svg or any other format.

Draw a line
Draw a line with the pen tool (the icon of a pen), press left click on the canvas to draw the first point, then press the left click in other part of the canvas to trace or make a line. In order to see the lines created choose a color and a stroke in the right menu.

Even when a line is easy to make and does not look to useful, can be use to cut pieces in a straight line (or curved line) in the cases we just want to cut a piece of material to reduce its form or make a new form.

Curved lines can be created choosing a initial dot and maintaining pressed the right click after pressing in the second point and moving it until the desired curve image is drawn.

Creation of texts
Select the option text (icon A in the left menu), type the text and then modify its size and color.

Change the stroke color to red if the text will be cut (rf00000) and the width of stroke to 0.72 points to cut.

If the object will be edged or raster use blue or other color and stroke.

Creation of shapes
Choose the shape tool, select a shape and draw it to create a rectangle, circle, star, etc.

A tool that is used to properly adjust the dots that form part of the lines or objects is the rule.

Creation of more forms
New forms can be easily created with the pen tool, just draw 2 or more points, then adjust their position of each dot changing the value for x (diagonal point) or y (vertical point). In inkscape this values are located in central and top area of inkscape and is always visible, to change them, just select the dot to be modified, beside them also can be changed the units from mm to inches or points.

x value of 0 is located at the beginning of the page in the left size and it increases towards the right side. y value of 0 is located at the beginning of the page in the top of the page and it increases towards the bottom of the page (canvas).

The coordinates are written in the form (x, y), for example the first dot can be located in 2 inches beside the left corner of the canvas and 2 inches down of the top of the canvas, making the first dot (2, 2).

For example: To create a triangle, can be used 3 points, to create a rectangle use four points. The shape tool can also be used.

A tool that is used to properly adjust the dots that form part of the lines or objects is the rule.

Round corners
The corners of created objects (with pen tool or shape tool, such as the rectangles and squares tools) can be rounded choosing the option select paths and noodles in the right menu (below the option select options) and the option round corners in the top menu draw, also can be choose the dots and move the circled widget dot until the desired roundness is achieved.

Use of the rule
To see the rule in the canvas press Ctrl + R or select view, rulers, show rulers.

A measuring tape can be used to measuring of physical objects or planed designs, and the using these measures to draw them in the canvas using the rule to choose the dots.

Use of the coordinates for each dot or object
The rule may not be necessary when using the x and y values, for example, drawing a straight line of 2 inches, the first dot can use the coordinate (2,2) and the second dot can use the coordinate (4, 2).

If a object has more than one dot, they can be aligned in the same way, for example a rectangle with 4 dots, 2 inches long can have the following dots:

(2, 2) (2, 4) (4, 2) (4, 4).

The objects can also be aligned with the align tool, for this, click in the window menu and choose align (control+shift +A) after selecting the edit nodes option and then using the right menu.

Changing the color of the lines or shapes
To change the color of a line or an object choose the option Fill: In this option the colors can be changed from CYMK to RGB, for cutting change the RGBA number to FF0000 (red). To change the color of a line or an object, click on the object, then in the properties window, appearance section, click on the square beside the fill option and in the filling space beside #, type the color number.

RGB color model uses a system of 6 number and letters, the three more used colors in laser cutting to indicate what type of task will be done with the line or object are the following:

Black, to raster etching (00000)

Blue, to vector etching (0000FF)

Red, to cut Cutting (ff00000)

Choose the color palette icon and type ff0000, this will create a red color, this will indicate the printer that the line or object will be cut, or 000000 to raster etch, or 0000ff to vector etch.

Cutting, vector etching and raster etching
Once you have designed an object use the color numbers to complete the desired task.

Cutting
Use red color, ff00000, this will cut the object in the desired shape.

Raster etching
Use black color, 00000, this will vector etch the design.

Vector etching
Use blue color, 0000FF, this will vector etch the design.

Create a path or vectorize a raster image
To vectorize an image with Inkscape select the following options: From the path menu choose the option Trace bitmap, the the option brightness cutoff, and select multiple scans (by colors 8 or 20).

The option object un-group, This will create 8 or 20 (depending the number of color selected), it will be 20 layers to choose between the parts, they will be overlay one over each one, they will be vectors.

If the options Path, un-group are selected, each layer can be moved to seen separated and be used or deleted. For logos or simple design can be selected 2 colors to separate use 2 (or 4 or 8) for logos. Move all not needed, leave the image or images that represent the desired image to use. Then can close path, and select image size to change its size and save it as svg, this image can also be seen in illustrator or be used in laser cutting machines.

Other useful options are outside edge e inside edge, these can be erased, and the option simplify to remove the number of dots.

The different colors allow to control and choose the order in which the object will be cut.

Print to sent the file to the laser cutting machine
To sent the document created to the laser cutting machine just press the keys Ctrl + p and choose the laser cutting machine, after this the file will be sent to the Universal Laser Systems control panel software, and from them the cutting can be started.