Dan Gelbart, a master prototyper and Creo founder, says that if a product can be made out of wire, it should be. It’s difficult to find a non-video source for this, but these UBC course notes are a good start. His rationale is the lack of waste (unlike sheet metal fabrication) and single-phase production with minimal post-processing.
In practice, it can be challenging to design a mechanism or even a part entirely out of wire. Regardless, a machine that can crank out precisely-bent wire lengths would be useful.
D.I.Wire Plus by Pensa Labs is a $4,325 wire bending machine for 2D (and some spring-like 3D) bends. It’s probably the cheapest CNC wire bender available. An open source version called the DIWire Bender was published on Instructables in 2013 before the company went to commercial production.
The Arduino 3D Wire Bending Machine by How To Mechatronics can bend in three dimensions for complex parts, but uses copper tubes as wire guides and has an unreliable feeder.
A Spring Making / Wire Bending Machine (also posted on Hackaday)was built by Jiri Praus in 2019 to help create brass wire mechanisms and springs. It’s only capable of 2D bends, but the system is a bit more polished than other DIY benders I’ve seen.
A DIY wire bending machine was posted on Code Make Share, but without many resources for building it. It’s limited to 2D and the system seems very minimal and simple to make.