In the following recipes, we are going to experiment with a printing technique called bridging. Bridging is a term that is used to describe a situation when a printer extrudes filament over a gap by spanning two points. The wider the two sides, the harder it is to maintain a layer that does not droop or fall when successive layers are placed on top. We can see this illustrated in the following image:

The cube we made in TopMod using the wireframe tool has an area to bridge from each post. The first layers must span this distance without sagging and also with enough strength to carry the load of successive layers.

Controlling speed is an important function of bridging. In Skeinforge and Slic3r, there are options that control the general speed of the printer and more specialized options that adjust the printer's speed for areas that require bridging. We'll take a look at some of these options in the following recipes.

For bridging to be successful, we first must have a good control...