Prototyping is an essential part of the design process and until the recent invention of 3D printing, it was time consuming and could be prohibitively expensive. Designers were limited to using computer models for visualization and product development. The 3D printer is a revolution in the design and iteration process; intricate computer models and scanned physical objects can be replicated in plastic without many of the tools and materials costs of CNC mills and lathes. When building from a mill or lathe a person must begin with a block of material, often representing over two times the final product volume, and then subtract material. 3D printing eliminates much of that waste as plastic filament is melted and adds material in thin layers.
There is a seemingly endless number of 3D printer manufacturers and models, from high-precision printers for thousands of dollars to DIY printers that you can build for less than $100. Some common features of these printers are stepper motors, stepper motor controllers, power supplies, and 3D filament. 3D printers often use NEMA 17 stepper motors. 1.75mm diameter 3D filament is widely used by many different 3D printers as it is light and flexible, preventing jams at the nozzle. Thicker filaments require stepper motors that supply higher torques, such as our 4.2 kg-cm NEMA 17 stepper motor.
PLA vs ABS Filament
PLA (polylactic acid) is printed at a lower temperature and is less prone to warping, which makes it better for printing without a heated printer bed. Because it is derived from sugar, PLA gives off a semi-sweet smell during printing. PLA has a lower melting temperature than ABS (acrylonitrile butadiene styrene) and it is also considered more environmentally friendly, since it is derived from plants (i.e. it is a renewable resource) and biodegradable. Keep in mind that PLA’s low melting temperature makes it unsuitable for a part that will be exposed to high heat. PLA flows more smoothly than ABS, providing precise and fast printing.
ABS is a stronger plastic overall and as a result can be sanded or machined. It is printed around 225°C (PLA is printed at about 200°C). ABS is also soluble in acetone, meaning you can give a shiny finish to a 3D printed part by applying a few drops of acetone to the surface. ABS will be more resilient than PLA for a part that is exposed to the elements and high temperatures.
HIPS (high-impact polystyrene) filament is another interesting option. If you have a dual extruder, you can print with ABS and HIPS and then dissolve the HIPS with Limonene, enabling you to create intricate shapes and voids that would be impossible to make without support.