Gerber to G-code – mill your PCB layout

Upload the Gerber export of your PCB program as a ZIP – from KiCad, Eagle, EasyEDA or any other program that writes Gerber and Excellon. step2gcode detects the copper layer, board outline and drill file, shows the board with all paths and writes one program per tool: isolation milling, drilling per diameter and cut-out with holding tabs.

For single- and double-sided boards on a CNC router – bottom side mirrored, alignment holes for turning the board over, programs for GRBL, LinuxCNC, Mach3 and Marlin. No installation, no account; only the download is charged, the first board is free.

The tool does not load in this view without JavaScript. To convert a PCB to G-code, open www.step2gcode.com/en/pcb-to-gcode in your browser.

From Gerber export to a milled board

Instead of setting up FlatCAM or pcb2gcode: upload the ZIP, choose the isolation tool (V-bit with angle and tip, or a small end mill), set depth and number of passes, check the preview, download the programs. The order and the tools are listed in a text file inside the ZIP.

What usually goes wrong when milling PCBs

  • Traces stay connected: Where copper lies closer together than the tool is wide, the path cannot pass between. step2gcode counts such places and warns before download – using the V-bit’s cutting width at the chosen depth.
  • Wrong side, wrong direction: The bottom side must be milled mirrored, or holes and parts will not line up. Here isolation, holes and outline are mirrored together.
  • The board breaks loose during cut-out: The cut-out runs in step-downs around the outline and leaves holding tabs; cut-outs inside the board are milled from the inside.

PCB to G-code: the features

  • Gerber RS-274X with aperture macros (including KiCad’s rounded pads), copper zones with clearances, arcs
  • Excellon drill files with and without decimal point, slots
  • Layers detected automatically: copper top and bottom, board outline, drill file
  • Isolation with a V-bit (angle, tip, depth) or an end mill, several passes
  • Drilling: one program per diameter, through the board
  • Cut-out along the outline with holding tabs, inner cut-outs
  • Bottom side mirrored, origin at the board corner, Z = copper surface
  • Warnings for gaps that are too tight, cut-outs that are too narrow and a missing outline

Your circuit stays your circuit

The ZIP file is read in memory only, never unpacked, processed solely to create the programs and the preview, and deleted after 24 hours at the latest. No analysis, no sharing, no cookies. Hosted in Germany.

Frequently asked questions

How do I convert Gerber files to G-code?

Export the Gerber files and the drill file from your PCB program and pack them into a ZIP (KiCad: Plot, layers F.Cu/B.Cu and Edge.Cuts, plus "Generate drill files"). Upload the ZIP, choose the side and the isolation tool, check the preview and download the programs. The order is isolation, drilling, cut-out.

Do I need the schematic?

No. What gets milled is the PCB layout, not the schematic: in your electronics program the schematic becomes the board layout, and the layout becomes the Gerber export with copper layers, outline and drill file. That export (as a ZIP) is what step2gcode reads.

Which programs are supported?

All that write Gerber RS-274X and Excellon: KiCad, Eagle, EasyEDA, Altium, Fusion Electronics and others. Layers are recognised by the file attribute (KiCad) or by the usual file names and extensions (.gtl, .gbl, .gko, .drl, .xln).

Which tool for isolation?

Usually a V-bit with 20 to 30 degrees and a 0.1 mm tip. Its cutting width grows with depth: at 30 degrees and 0.08 mm depth it is about 0.14 mm. A small end mill (0.4 to 0.8 mm) cuts more evenly but needs more clearance between traces.

Why one file per tool?

Most hobby machines change tools by hand. After every change, Z is zeroed on the copper surface again and the next program is started. All programs come together in one ZIP and cost one credit together.

Can I mill a double-sided board?

Yes. First two alignment holes are drilled on the middle axis outside the board, then the top side is milled and drilled. The board is then turned over its middle axis, pins in the alignment holes hold it in the same place, and the mirrored bottom side lines up with the holes. X and Y stay, only Z is zeroed again.

Can the unused copper be milled away?

Yes, if you want. A separate program with a larger end mill clears all copper that is not part of the circuit – after the isolation, keeping clear of the traces.

Which controller is the G-code for?

Plain G-code with G0, G1, M3 and M5 in millimetres, selectable for GRBL, LinuxCNC, Mach3 or Marlin – for Marlin with semicolon comments and without M30, for Mach3 without a G4 dwell. The header lines name tool, depth and origin.

What does it cost?

Uploading, adjusting and previewing are free. Only the download is charged: your first board is free, after that a new board costs one credit – for all its programs together.

CNC milling: STEP, DXF and SVG to G-code