Making Wire Stripping and Cutting Easier with an Automated System
Anyone with experience in electronics prototyping has encountered the age-old problem of having to manually measure, mark, cut, and strip every single jumper wire for use on a breadboard or protoboard. But what is even more annoying that this tedious process is that it results in varying lengths, which are not accurate, thus making circuits quite messy.
Out of frustration and a willingness to improve the process, the YouTuber who goes by Projects with Red (Reda) was able to construct a machine that could accomplish both tasks with incredible amounts of precision, accuracy, and speed.
At the core of the design was a spool of wire, some way to unwind it from the spool precisely, and a method for cutting and stripping it at distinct intervals. Although the spool and wire puller were simple enough to easily integrate, the cutting mechanism required a bit more creativity since it had to strip the wire without cutting it entirely until the very last step.
Taking inspiration from another machine, which unwinds material from a spool, Reda decided to extract a filament extruder from an FDM 3D printer that is already ideal due to its internal spring-loaded guide wheel and gripping drive gear. Even better is the fact that the extruder is driven by a single stepper motor, which can be turned in extremely small increments accurately for producing many identical lengths of wire.
The last step of the process was the cutting/stripping tool, and it was fashioned from a pair of blades which essentially surround the wire akin to a guillotine. The bottom blade was securely affixed to the base of the machine whereas the top one was free to move along a vertical axis with the help of two stepper motors beside it.
When they spin the threaded rods counter-clockwise, the top blade is forced down onto the wire's insulation but not through the copper core in order to strip it. Then when the time comes to make a cut, the stepper motors spin even more in the same direction to slice completely through and let the wire fall neatly into a collection tray waiting below.
To make everything run properly and collect user inputs regarding various lengths and depths, an ESP32 was combined with a set of three A4988 stepper motor drivers which, in turn, each drive a single NEMA17 stepper motor. The machine's user can set certain parameters by turning the onboard rotary encoder to make a selection and then adjusting the corresponding value.
With the machine completed and some parameters entered to create a pair of 22-gauge jumper wires that were 50mm long with 10mm of exposed conductor on each side, Reda was able to demonstrate that both look identical and had the correct measurements. Further experimentation only drove home this point even further, making this project a success.