RepRap

RepRap is a family of open-source 3D printers designed to be capable of printing many of their own parts. The project originated in the early 2000s with engineer Adrian Bowyer at the University of Bath, who proposed that a self-replicating machine could accelerate low-cost manufacturing. The term RepRap stands for Replicating Rapid Prototyper. The hardware is typically based on fused deposition modeling using thermoplastics like ABS or PLA, printing components such as gears, housings, and some structural parts. Non-printable components such as motors, electronics, bearings, fasteners, and raw aluminum or steel rods must still be obtained from outside sources.

RepRap printers rely on open-source hardware and software, with publicly available design files in formats such as STL and STEP, and licenses that encourage sharing and modification. The project emphasizes community-driven development and distributed manufacturing, with multiple design families and iterations, and many derivatives have become popular in hobbyist and educational settings. Notable variants include Mendel, Primo, and the Prusa lineage, among others. Progress toward fully self-replicating machines has advanced, but practical replication of all components remains challenging; however, many printers can print a majority of their own parts, enabling rapid prototyping and experimentation.

RepRap has had a lasting influence on the open-source hardware movement and on the broader adoption of low-cost, accessible 3D printing. It helped catalyze commercial-off-the-shelf open architectures and inspired a wide ecosystem of self-reprinting hardware, software tools, and user communities.