As we've seen in previous posts on Turtle Patterns and Turtle Shapes moving your turtle around the screen is done by simple dictional commands and angled turns.
A similar process happens in 3D printing with DIY plastic extrusion hardware, such as Rep Rap, RepRap Pro and Makerbot.
Here the 3D printing extrusion nozzle is moved in a particular direction and for a specific length, before it halts and waits for a new instructions.
So, we could use Python Turtle code to simulate a 3D printing layer. Then put it into a repeating loop to create multiple layers. This loop could subtly change the direction and length commands to build quite complex and intricate shapes.
Here's a video of a Turtle code driven 3D printer in action.
The video was part of this 3D Printing presentation at the IPSJ Summer Programming Symposium in 2014.
The presentation also included a 3D Printer Turtle Graphics Python module and a code example of the module in use.