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TURN A DEAD 3D PRINTER INTO A 109,500-DOLLAR METAL CUTTER

A brass wire thinner than a paperclip cuts through tungsten carbide and hardened steel with electrical sparks, and an old Ender 3 becomes the motion platform.

by Almost Completed Projects

FULL CAD BOM FIRMWARE DOCS

WorkshopOpen-hardware

difficulty
●●●●●
time
a weekend-plus
license
not stated
repo
repo ACTIVE114 stars

WHAT YOU’LL NEED

  • 3D printer + filament — printable parts — files are in the repo
  • Electronic parts — full list with part numbers in the repo BOM
  • Dev board / microcontroller — runs the project firmware

Partner

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Videos
1

COMPAREE VERDICT

EnderSpark is a real wire EDM built on an Ender 3 frame, and the parts list, PCB files and mechanical models are all published. Wire EDM is the process for cutting hardened tool steel, tungsten carbide, and parts so thin a milling cutter would destroy them: a brass wire erodes conductive metal with electrical sparks in a dielectric bath, so there is no cutting force and no heat-affected zone. The conversion keeps the Ender 3 motion system but adds 1:51 gear reductions (lead screw plus belt reducer) to X and Y because EDM cuts slowly and steppers at normal ratios are far too fast. A Raspberry Pi Pico with a TC4428 gate driver and MOSFET generates discharges at up to 10 A and 60 kHz. Parts come to roughly 250 EUR plus four machined components and under 50 hours of work. The single thing most likely to go wrong is the absence of assembly documentation: the repository gives you the files but not the procedure, so you are reverse-engineering the build from a 19-minute video and your own machining and high-current experience. The voltage in a wet conductive tank is lethal, copper waste must be disposed at a recycling centre, and the machine emits strong EMF. This is for people who already work with high current and have access to a lathe or milling machine. A new Mitsubishi MV-2400S wire EDM was listed at 109,500 dollars; this costs a few hundred euros and a donor printer, but it will not hold the tolerances or duty cycle of an industrial machine.

NOT IN THE REPO

  • —STEP files for mechanical parts, Gerbers and schematics for the PCB, firmware configuration for Ender 3 V2, and an SVG for the laser-cut water tank are all in the repository.
  • —The electronics BOM is published, but four machined parts are required and the repository does not include drawings or G-code for those — you machine them from the STEP files or source them yourself.
  • —There is no assembly guide, no tuning guide, and no documentation on dielectric fluid circulation or wire tension setup beyond what is in the video.
  • —Licence is not stated in the repository. No LICENCE file, no header in the code, no terms in the README.
  • —The project assumes you already know high-current electronics, EDM principles, and CAM workflow — it is not a teach-yourself-from-zero build.

Can I build this?

Printnothing required for the conversion itself — the donor is a 3D printer, not a 3D-printed build
BuyEnder 3 (donor), two 1:51 gear reductions (lead screw plus belt reducer), Raspberry Pi Pico, TC4428 gate driver, MOSFET, passives per BOM, PCB fabrication, brass wire, dielectric fluid, laser-cut acrylic sheet for water tank, four machined parts (lathe or mill required)
Toolslathe or milling machine to make the four machined parts, soldering station, multimeter, oscilloscope (strongly recommended for tuning pulse timing), basic hand tools
Skillsintermediate-to-advanced machining, intermediate electronics including gate driver circuits and high-current switching, CAM workflow (Fusion 360 post processor is included), EDM principle knowledge, and comfort working with lethal voltages in wet conditions
Timeunder 50 hours including machining the four parts, assembling the mechanics, building and testing the electronics, and first tuning — more if you are learning EDM principles or debugging pulse timing
Cost$$$, dominated by the gear reductions, the donor Ender 3 if you are buying one, PCB fabrication, and machining time or outsourcing the four parts
Safetylethal risk — mains-equivalent voltage in a conductive water tank, strong EMF emissions (relevant for cardiac devices), and copper-laden waste water that must be evaporated and disposed at a recycling centre, not poured down a drain

This build involves mains voltage — for adults comfortable with electrical work only.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

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Videos

EnderSpark build and operation video

19-minute video showing the build, first cuts, and close-up spark footage — this is the primary assembly reference because the repository has no written guide

Gallery

https://img.youtube.com/vi/iLnna7q0drs/maxresdefault.jpg

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Watch the full video first (the repository has no assembly guide — the video is your build reference)
  2. 2.Check the BOM and verify you can source or machine the four unlisted parts (STEP files are provided but not machining drawings)
  3. 3.Order the PCB from the Gerbers(schematics are in the repo — review them before ordering)
  4. 4.Plan dielectric circulation and wire tension — neither is documented(you are designing this part yourself from EDM first principles)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

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KNOWN ISSUES

  • The repository does not include machining drawings or G-code for the four required machined parts — you work from STEP files or find a machine shop that will.
  • There is no assembly manual, no tuning guide, and no documentation on dielectric fluid setup or wire tension — the 19-minute video is the only reference.
  • The licence is not stated anywhere in the repository, so commercial use and redistribution terms are undefined.
  • Planetary reducers at 1:51 ratio are not standard hobbyist parts — verify availability and lead time before starting.
  • The electronics assume you already know gate driver circuits and high-current MOSFET switching — if you have never tuned pulse timing on a scope, this is the wrong first project.
  • Copper-laden waste water cannot go down a drain — you need an evaporation and recycling disposal plan before the first cut.

Can I use a different 3D printer as the donor?

Yes, the principle works on any motion platform with enough travel, but the firmware configuration and mounting points are specific to the Ender 3 V2 — you will need to adapt both.

What is the thinnest part I can actually cut?

Wire EDM is capable of paper-thin cuts because there is no mechanical force, but this build's accuracy depends on your Ender 3's frame rigidity and the backlash in the reducers — it will not match an industrial machine's tolerances.

Do I need the exact Raspberry Pi Pico, or will a clone work?

The schematic and firmware are built for the Pico, but any RP2040 board with the same GPIO pinout should work — verify the pin assignments before powering up.

What dielectric fluid do people actually use?

Deionised water is common for home EDM, but the repository and video do not specify what this build uses — check the video comments or ask the creator.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

Wire EDM cuts tungsten carbide and zero-clearance parts a mill would destroy, and this conversion brings it under 250 euros of parts — what would you cut first if you built one?

CompareeTEAM6d agoedited

Practical notes from our verification: the repository publishes Gerbers, schematics, STEP files for the mechanical parts, firmware configuration for the Ender 3 V2, an electronics BOM, and the SVG for the laser-cut water tank, but there is no LICENCE file and no assembly guide. The 19-minute video on YouTube is the only walkthrough, and four machined parts are required but not documented beyond the STEP files — you machine them yourself or find a shop that will. The single biggest trap is not the electronics or the motion platform, it is the absence of documentation on dielectric circulation, wire tension setup, and pulse tuning, all of which are critical to a working EDM and none of which are explained. This is a real wire EDM and the files are all there, but it is for people who already know high-current switching and EDM principles, not a learn-as-you-go build. Correction 21 August 2026: the X and Y reductions were described here as planetary reducers. They are not - the build uses T8 lead screws with a 2GT belt reduction and anti-backlash nuts. The author's own README quotes the overall ratio as 1:51 while also describing a 1:3 belt reducer, so treat the exact figure as the author's number rather than something we verified.

Almost Completed Projects

Almost Completed Projects publishes experimental machine conversions and open hardware builds. EnderSpark applies industrial EDM principles to a hobbyist motion platform, with all electronics and mechanical files released.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo