Inkscape/glowforge

We use the glowforge laser cutter in our makerspace. This is the notes from a lesson I gave on how to use the glowforge.

Raster vs vector

There are two different ways you can represent images, as an array of pixels (we call these raster images) or as a set of shapes (we call this vector images). The glowforge can engrave raster images, the laser will scan back and forth across the substrate like an old television, but for things like cutting or scoring you want to be using vector images.

[demonstration of vector vs raster]

Everything is an object

We use the free and open-source software inkscape for editing vector images.

In vector-image editing software like inkscape your drawing is composed of a number of "objects", those objects can be things like sqaures, triangles, circles, etc. Most of those higher-level objects are made out of a different type of object, a path.

[demonstration of path, editing the curve of a path]

Paths are what the glowforge understands best, the laser will literally follow the path cutting (or scoring) along the line you've drawn.

Objects are made of paths, mostly

A path is composed of a number of nodes, you can curve them via "bezier curves". These nodes and curves are what the glowforge actually understands. The glowforge will use it's own internal software to reduce more complicated objects like those squares and circles into a path, and we can do the same.

[top menu > path > object to path]

Sometimes you need to make sure an object is actually made of paths

There are some types of objects the glowforge can't convert into a path though, the most important one is text/fonts. Since the glowforge doesn't have font files it can't know what shapes the fonts are supposed to be.

[demonstration of converting text to a path]

[demonstration that it is no longer editable with the text tool]

There are also features of proprietary vector editors (like adobe illustrator) that won't be supported. Always make sure your file is saved as an .svg file, and avoid complicated features like clip-paths and gradients.

Each color is a different type of laser cut

The glowforge presumes that each color is it's own type of path, and groups things appropriatly. We use red for lines that we want to cut. One thing to be aware of is just because you can't see a line doesn't mean it doesn't exist. A line can be covered up, but it still exists and the glowforge will still cut it.

You can combine shapes using CSG operations

One thing that you will probably find very usefull is the "CSG operations", the ability to cut a shape out of another shape, or combine two shapes.

[demonstration of difference, union, intersection, etc]

[top menu > path > difference, union, etc]