Desktop EDM Drill

An open source, desktop-scale electrical discharge machining (EDM) drill — a hobbyist/maker-accessible machine for sinking small, precise holes (including in hardened steel and carbide) using spark erosion instead of mechanical cutting.

This site is the working manual and design log for the project. It grows alongside the machine: as decisions get made, they get written down here so they’re reviewable, printable, and usable offline in the shop.

Why EDM drilling first

EDM drilling (hole-popping) is the simplest member of the EDM family to build a first machine around:

Single-axis motion (Z) is enough for a useful tool — no gantry, no wire tension control.
Tooling electrodes are cheap, simple round tube or rod stock.
It solves a real problem hobbyists hit constantly: broken taps and drill bits stuck in hardened or expensive parts.
The pulse generator, dielectric handling, and control electronics built here are the same subsystems a wire EDM or a combined machine will need later.

Where this is going

This project is planned in stages:

Desktop EDM drill — this repo. Single-axis hole popping, small work envelope, benchtop footprint.
Desktop Wire EDM — reuses the pulse generator and control core, adds wire transport, tensioning, and XY (and eventually taper) motion.
Dual-EDM machine — a shared frame/control platform that can run either as a drill or a wire EDM, so the electronics and firmware investment pays off across both machine types.

Nothing below the drill stage is committed yet — see Roadmap & Open Questions for what’s still undecided.

danger

EDM machines involve high-voltage pulse generation and a dielectric fluid bath. Nothing in this repo should be built or powered on until the Design Goals & Constraints safety section has real content, not just a placeholder.

Start here

Design Goals & Constraints — what this machine is and is not trying to be.
Roadmap & Open Questions — the current state of the design and what’s still unresolved.