Creating a bridge with a 3D pen involves a specific technique distinct from simply drawing vertically into the air. It is a key skill that allows you to connect two points or surfaces with a free-standing line of filament.
Understanding 3D Pen Bridging
Based on expert tutorials, bridging with a 3D pen means drawing a line of filament that spans a gap between two anchor points or surfaces without any support directly underneath it.
Unlike drawing a vertical tower or abstract shapes that stand on their own, bridging requires the filament to successfully solidify while suspended between two existing structures.
- Drawing into the air: Creating unsupported structures or lines that start from a base.
- Bridging: Connecting two points or surfaces with a line that has nothing underneath. This is the crucial distinction mentioned in bridging tutorials.
The Basic Technique
To make a bridge using a 3D pen:
- Establish Anchor Points: You need two stable points or surfaces that your bridge will connect. These could be part of a pre-existing 3D print, drawn supports, or simply two points marked on a surface you are working above.
- Start Drawing: Begin extruding filament while touching the pen tip to your starting anchor point.
- Span the Gap: While extruding, smoothly move the pen tip across the gap towards your second anchor point. The speed is crucial – too fast and the filament might break or sag excessively; too slow and you might build up too much material or struggle to keep the line straight.
- Connect to the End Point: Once you reach the second anchor point, firmly connect the filament stream to it and stop extruding.
Successfully bridging requires finding the right balance of pen speed, extrusion rate, and filament cooling. The filament needs to be cool enough to hold its shape across the gap but malleable enough to adhere to the anchor points.
Tips for Effective Bridging
- Control Speed: Experiment with how fast you move the pen. A consistent, moderate speed often works best for shorter bridges.
- Cooling: Ensure your pen's settings are appropriate for the filament type. Some pens have adjustable fan speeds which can help cool the extruded plastic faster, improving bridging capability.
- Short Segments: For longer bridges, you might build it up in multiple passes or layers, but the fundamental technique involves creating that initial unsupported span.
- Practice: Mastering bridging, where the filament is "pending from one surface" and has "nothing underneath," simply takes practice.
By understanding that bridging is specifically about spanning a gap between two points without underlying support, you can focus on controlling the filament's trajectory and cooling to create stable connections.
