A recent video on the Functional Parts Friday YouTube channel demonstrates how to make bellows using thermoplastic polyurethane (TPU) filament in fused deposition modelling (FDM) 3D printing.
The process involves printing TPU and polylactic acid (PLA) in alternating layers, ensuring that the TPU is connected to its previous layer in an alternating fashion, before peeling the two materials apart.
Users require a 3D printer with two independent extruders, like the Bambu Lab H2D, as TPU and PLA do not mix.
There are some challenges to this process, such as differences between TPU brands and incompatibility between Bambu Lab AMS and TPU, which can lead to brittle TPU prints.
Bellows can be used for lathe way covers and soft robot actuators, or to create custom parts such as those used on a CNC machine.
