Spring Forming Machine

Springs, as Harshad Byadgi notes in his project write-up, “are pretty simple, yet amazing.” The problem, according to him, is that they can be difficult to source in small numbers at a reasonable price. His solution: a machine to make your own springs out of unbent wire!

The device uses largely 3D-printed parts, with a number of metal hardware components to create sufficient contact force on the wire to bend it into shape. Wire movement is accomplished with two razor blades, cleverly held in an apparatus that bites into the wire in a forward motion, but releases when pulled back.

When pushed – forced – forward, the wire travels through a nozzle, where it contacts a bearing surface that rolls it over… and over and over into the familiar helical spring pattern. The bearing can be adjusted up or down, which in turn makes the spring diameter smaller or larger.

Movement of the gripper assembly is handled by a DC gearmotor, which uses a screw for linear movement and further gear reduction. Once the gripper position travels fully forward, the motor reverses and pulls it back for another cycle. This cyclical motion is regulated via two microswitches on either end of the device's travel, along with a number of discreet components (sans microcontroller).

The machine also features a wire straightener assembly. This was a bit of an afterthought, but it improves the quality of the finished springs by straightening the wire, but most of all by keeping the wire from twisting during the process.