kicad2print

Convert KiCad PCB designs into 3D-printable substrate models for the hybrid PCB construction method — a technique that replaces traditional PCB fabrication with a 3D-printed substrate and copper traces, using either laid copper wire or electroplated copper.

The generated build guide: assembly steps, an interactive continuity test that pulses probe dots on every pad of the selected net, and an embedded 3D model — all in one self-contained HTML file.

Example: ps2-serial-mouse-adapter — view the interactive 3D substrate model.

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What is the hybrid PCB method?

Instead of sending your board to a fab house, you print the substrate on an FDM printer and add copper traces yourself. kicad2print supports two construction modes:

Copper wire traces (--mode copper-wire, default)

1. Design your PCB normally in KiCad
2. Print the substrate — grooved channels for traces, holes for pads and vias
3. Lay 30 AWG copper wire into each channel
4. Press copper eyelets into via holes to bridge top and bottom layers
5. Solder your components

No chemicals, no etching, no minimum order. A functional PCB in a few hours.

Electroplated copper (--mode electrolysis)

1. Design your PCB normally in KiCad
2. Print the substrate — narrower grooves sized to the actual trace width — plus the snap-on stencil kicad2print generates alongside it
3. Apply conductive primer — snap on the stencil and squeegee paint so it lands only in the grooves (optionally have the stencil also lay down a temporary bus that shorts every trace for plating)
4. Electroplate copper into the grooves using a copper sulfate bath
5. Test traces (grind off the bus first if you used one), then solder your components

Produces thinner, more accurate traces and no wire handling. The auto-generated stencil keeps paint out of the flat areas (minimal cleanup), and can optionally build the "every net must reach the cathode" plating bus for you (--plating-bus). Requires a simple electrolysis setup — see docs/ELECTROLYSIS.md for the full end-to-end procedure: seed paints, bath chemistry, sourcing, plating run, and installing eyelets before plating so they become part of the copper layer.

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kicad2print handles the substrate step: it takes your .kicad_pcb file and produces the STL/3MF model ready to slice and print, plus an HTML assembly guide tailored to whichever mode you choose.

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Installation

Download the binary for your platform from the Releases page.

Linux:

chmod +x kicad2print-linux-x86_64
sudo mv kicad2print-linux-x86_64 /usr/local/bin/kicad2print

Windows: download kicad2print-windows-x86_64.exe and place it on your PATH.

Snapshot build (latest main branch): download from the snapshot release.

Build from source

git clone https://github.com/N0t4R0b0t/kicad2print.git
cd kicad2print
cargo build --release
# binary at: target/release/kicad2print

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Usage

# Basic conversion — copper wire mode (default)
kicad2print my_board.kicad_pcb

# Electrolysis mode — narrower channels, plating assembly guide
kicad2print my_board.kicad_pcb --mode electrolysis

# With a config file (copy a preset as a starting point)
kicad2print my_board.kicad_pcb --config presets/electrolysis.toml

# Override individual settings on top of a mode
kicad2print my_board.kicad_pcb --mode electrolysis --channel-width 0.5

# Generate both STL and 3MF
kicad2print my_board.kicad_pcb --format both

# Auto-open the HTML 3D preview after conversion
kicad2print my_board.kicad_pcb --view

Output files

By default a board is split into two half-thickness, glueable pieces rather than printed as one full-thickness slab — each prints right-side-up with its own copper features facing up, so neither layer ends up formed by a print's worst layers (the first few, still fighting first-layer squish) the way one of the two would on a monolithic board. Glue the flat, featureless backs together after printing to reconstruct the configured substrate thickness.

Each run produces the following in --output-dir (default ./output/):

File	Description
boardname_top.stl	F.Cu half, half the configured substrate thickness (when format = stl or both)
boardname_bottom.stl	B.Cu half, half the configured substrate thickness (when format = stl or both)
boardname_top.3mf / boardname_bottom.3mf	3MF with metadata (when format = 3mf or both)
boardname_preview.html	Interactive 3D preview of the assembled (glued) board
boardname_guide.html	Unified build guide — tabbed view with assembly steps (including gluing the two halves), continuity test, and an interactive 3D preview, tailored to the selected mode

Pass --side top or --side bottom to generate only that one piece — just the STL/3MF, at half thickness, with no preview, guide, or stencil. Pass --side full for the traditional single-piece, full-thickness board instead of a glued pair — same "just the STL/3MF" contract, no gluing required.

Open the guide in any browser — no server needed.

What's in the unified guide

• Assembly tab — step-by-step instructions for the selected mode (wire-laying or plating), with images and the BOM.
• Continuity test tab — an interactive SVG board diagram. Pick a net from the sidebar and probe dots pulse on every pad that should be electrically connected, so you can verify continuity with a multimeter after wiring or plating.
  • Through-hole and SMD pads (e.g. SOIC, SOT, QFN) are included — anything with a net name gets a probe dot.
  • Power-rail nets that KiCad didn't name in the schematic (the unconnected-* nets KiCad auto-creates when 2+ pads share a node) are detected and listed with a ⚠ marker, so power and ground continuity can still be verified.
• 3D preview tab — the same interactive three.js viewer, embedded directly in the guide.

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Configuration

Quick start with a preset

Copy one of the presets from this repo as your starting point:

# Copper wire traces (default settings)
cp presets/copper-wire.toml kicad2print.toml

# Electroplated copper
cp presets/electrolysis.toml kicad2print.toml

Then edit kicad2print.toml to taste and run:

kicad2print my_board.kicad_pcb --config kicad2print.toml

Or skip the file entirely and use --mode for the preset defaults:

kicad2print my_board.kicad_pcb --mode electrolysis

All settings

Setting	Copper wire default	Electrolysis default	Description
mode	copper-wire	electrolysis	Selects assembly guide style
channel_width_mm	1.2	0.7	Groove width — wire diameter or trace width
channel_depth_mm	0.5	0.5	Groove depth
channel_profile	rect	trapezoid	Groove cross-section: rect, trapezoid, or vee
channel_floor_width_mm	0.4	0.4	Groove floor width for trapezoid (opening stays at channel_width_mm)
taper_slice_height_mm	0.2	0.2	Step height for sloped walls — set to your slicer's layer height
via_style	straight	straight	Barrel shape: straight, or cone for eyelet-free plated holes
cone_angle_deg	45.0	45.0	Countersink wall angle from the board surface (cone only)
throat_height_mm	0.4	0.4	Straight section where the two cones meet (cone only)
min_rim_mm	0.3	0.3	Material kept between a cone mouth and foreign-net copper (cone only)
eyelet_diameter_mm	1.5	1.5	Minimum via bore diameter
pad_hole_diameter_mm	0.8	0.8	Minimum component pad hole diameter
substrate_thickness_mm	3.0	3.0	Total board thickness
scale_factor	0.0	0.0	0 = true 1:1 scale; >0 = exact multiplier
output_format	stl	stl	stl, 3mf, or both
output_dir	./output	./output	Output directory

Settings are merged in order: built-in defaults → TOML file → CLI flags.

eyelet_style, indent_depth_mm and --no-via-indents are deprecated and inert. They never changed the generated geometry — vias have always been cut as full through-holes — and the tool now says so when they are set. Use via_style instead.

Groove profiles

rect (default) — vertical walls and a flat floor. What wire mode wants, so the wire seats flat against the floor.

trapezoid / vee — sloped walls. A trapezoid descends to a deliberate flat floor of channel_floor_width_mm; a vee ignores that setting and converges, letting the slicer truncate it where the groove gets too narrow to extrude. These matter for electroplating. A square-bottomed groove plates unevenly: current density is highest at the top corners and lowest at the floor centre, so copper grows inward from the walls and can seal over the opening — leaving a void — before the floor is covered. Removing the corner lets the groove fill from the bottom up. Sloped walls also print better on a 0.4 mm nozzle, most of all on the underside, where a square groove has to be closed off by bridging a flat ceiling. The trade-off is copper cross-section: a vee carries roughly half of what a rect does at the same width and depth, so prefer trapezoid where current matters.

Via styles

straight (default) — a plain bore. The two copper layers are otherwise completely separate, and you cannot get a brush down a small hole through a couple of millimetres of plastic, so the barrel never plates. Bridge the layers with a pressed-in eyelet, or — usually far less painful — a snipped component lead soldered on both faces.

cone — countersunk from both faces, meeting at a short straight throat. Every point of the barrel is then in line of sight from one face or the other, so seed paint can actually be applied and plating grows from both mouths toward the middle. No eyelet, no flange to trim. The bottom cone doubles as a solder cup, which is what makes a top-side trace solderable from underneath.

Cone mouths are much wider than the bore — a 0.8 mm hole with 45° walls through a 2.2 mm board wants a ~3 mm crater per face — so on fine pitches they are shrunk automatically to keep min_rim_mm clear of other nets, and holes with no room stay straight. The run reports how many.

The countersink is built from the same band stack that forms the trace grooves, so it works with every groove profile. Cone depth is bounded by channel_depth_mm for that reason, with throat_height_mm applying whichever is tighter.

Mesh validation

Every generated mesh is checked for being a closed, consistently-wound solid, and the result is reported. This matters because the failure modes are invisible in a 3D preview: an open surface is what lets a slicer fill a through-hole solid or render the board as a featureless plaque. The check also reports genus, which verifies the through-holes are topologically present. Don't print past a warning.

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Tips for printing

• Layer height: 0.2 mm works well for most channel widths. Use 0.1 mm for narrow channels (< 1.0 mm).
• Infill: 40–60% rectilinear. Higher infill = stiffer board.
• Material: PLA is fine for most projects. PETG if you need heat resistance (e.g., near a power section).
• Orientation: print flat (board face up). Support is not needed for the trace grooves.
• Sloped walls: if you use channel_profile = "trapezoid"/"vee" or via_style = "cone", set taper_slice_height_mm to your layer height. Sloped walls are built as a stack of thin bands, and at layer height the printed part is identical to a smooth ramp.
• First layer: a good first layer matters — the bottom pad holes need to be clean for component insertion.

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MCP server (Claude Desktop)

kicad2print also ships an MCP server that lets Claude Desktop read and make small edits to your KiCad project — useful for quick targeted changes like swapping a footprint, checking the BOM, or running DRC without opening KiCad.

These tools will not replace KiCad and can make your board worse. Read docs/MCP_KICAD_TOOLS.md before using them on a board you care about. Commit your work before starting any AI editing session.

Setup

Add to ~/.config/Claude/claude_desktop_config.json (Linux) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "kicad2print": {
      "command": "/usr/local/bin/kicad2print",
      "args": ["--mcp"]
    }
  }
}

Restart Claude Desktop. The KiCad tools will appear automatically.

What you can do

• Scan a project — get a rendered board image, full BOM, and file list in one shot
• Inspect before routing — query pad positions, check net names, verify clearances before touching traces
• Swap a footprint — e.g. change an Arduino Uno to a Nano without opening KiCad
• Check the BOM — export a CSV of all components and quantities
• Run DRC — get a JSON report of violations with a board render
• Convert to substrate — generate the printable STL/3MF directly from the chat

Example

You:    Scan my project at /home/me/myboard/kicad
Claude: [renders the board, shows BOM, lists all files]

You:    What nets are on this board and which pads carry VBUS?
Claude: [calls list_nets — returns every net name and connected pad list]

You:    Check if a 0.4mm trace from (97,63) to (113,63) on B.Cu is safe
Claude: [calls check_trace_clearance — reports any pad collisions before routing]

You:    Convert it to a printable substrate
Claude: [runs kicad2print conversion, returns STL + preview]

Key tools

Tool	Description
scan_project	Start here — renders board, returns BOM and file list
list_nets	All nets with connected pads — call before any edit to get correct net names
get_net_for_pad	Net name and absolute position of one pad
query_pads_in_region	All pads in a bounding box — inspect an area before routing
query_traces_in_region	All trace segments in a bounding box — pairs with query_pads_in_region
check_trace_clearance	Collision check vs. pads and existing traces — run before add_trace, or pass add_trace(check: true)
delete_trace	Remove trace segments by net/layer/uuid/region — the fix for bad routing, with dry_run support
verify_connectivity	Confirm two pads are physically wired by existing traces/vias
add_power_symbol	Place a power net symbol with correct lib_symbols definition
render_pcb	Render the board (top / bottom / side views)
run_drc	Design Rules Check — JSON report + board render
export_layer_svg	Export copper layers as SVG + PNG image
replace_footprint	Swap a component footprint in the PCB file
convert_pcb	Convert PCB to 3D-printable substrate (STL/3MF)

See docs/MCP_KICAD_TOOLS.md for the full tool list, risk levels, recommended workflow, and known limitations.

Note: render_pcb and export_layer_svg require kicad-cli (part of KiCad 9+). export_layer_svg PNG output requires rsvg-convert (librsvg). Footprint search requires the kicad-library package (sudo pacman -S kicad-library on Arch/Manjaro).

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Claude Code plugin (recommended for agents)

The MCP server above also installs as a Claude Code plugin, which — unlike Claude Desktop — can bundle custom subagents alongside the MCP tools. This repo self-hosts its own plugin marketplace.

Prerequisite: the kicad2print binary must already be installed and on your PATH (see Installation above) — the plugin points at it by name, it doesn't bundle the binary.

/plugin marketplace add N0t4R0b0t/kicad2print
/plugin install kicad2print@kicad2print

Claude Desktop has no concept of agents — it only reads the plain MCP config shown above. Use the Claude Code plugin if you want the bundled agent(s) as well as the MCP tools.

The plugin also bundles six skills — safe editing, PCB routing, schematic editing, project creation, and two for contributors working on kicad2print itself. They load automatically when the task matches. See docs/MCP_KICAD_TOOLS.md.

The bundled agent is kicad-worker (agents/kicad-worker.md), which runs the tool-heavy calls — DRC/ERC, reads and greps, position and net lookups, renders, specified edits — on a cheaper model and reports back a summary. These tools return large payloads, and keeping them out of the main conversation leaves room for the actual design reasoning. Give it decided work, not decisions. See docs/MCP_KICAD_TOOLS.md.

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Troubleshooting

Symptom	Cause	Fix
Failed to read KiCad file	Wrong path or unreadable file	Check the path; confirm the file is a .kicad_pcb, not a .kicad_sch
No board outline found	Missing geometry on the Edge.Cuts layer	Add a board outline in KiCad (Place → Line on Edge.Cuts)
Channels printed too narrow to fit wire	Source traces narrower than channel_width_mm and scale_factor is non-zero	Set scale_factor = 0 to auto-scale, or increase scale_factor
Eyelets won't press in	eyelet_diameter_mm smaller than your eyelets	Measure your eyelets with calipers and update the setting
MCP render_pcb fails	kicad-cli not on PATH	Install KiCad 9+
MCP search_footprint returns nothing	KiCad footprint libraries not installed	Install kicad-library (e.g. sudo pacman -S kicad-library on Arch/Manjaro)

How the conversion works

.kicad_pcb
    │
    ├─ parser/sexp.rs     Tokenize S-expressions → SexpNode tree
    ├─ parser/kicad.rs    Walk tree → PcbData (traces, vias, pads, outline, cutouts)
    ├─ autoscale.rs       Scale board so narrowest trace fills a channel
    ├─ geometry/          Tessellate 3D substrate mesh with grooves and holes
    ├─ export/stl.rs      Write binary STL
    ├─ export/threemf.rs  Write 3MF (ZIP + XML)
    └─ export/html.rs     Write self-contained three.js preview

Coordinate convention: KiCad uses Y-down; kicad2print negates Y at parse time so all geometry operates in standard Y-up coordinates.

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Building & development

cargo build           # debug
cargo build --release # optimised
cargo test            # unit tests
cargo clippy          # lints
cargo fmt             # format

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License

AGPL-3.0 — see LICENSE.