Turn an STL or STEP into simultaneous 4-axis rotary G-code — without an expensive CAM subscription. A from-scratch CAM program for hobby machinists with a rotary (4th) axis, running grblHAL · GRBL · Genmitsu · FluidNC · AtomStack · HolzProfi HC-204A · Makera Carvera · LinuxCNC · Mach3/Mach4 · Centroid · MASSO · RosettaCNC — plus drop-in custom posts for anything else. Free Community Edition for Windows.
Lay a model in the chuck and get continuous simultaneous X+C+Z roughing and finishing toolpaths, wrapped rotary engraving, and flat 2D engraving — with a 3D backplot and a material-removal simulation so you can verify the program before you ever cut.
⚠️ EXPERIMENTAL — read this before you cut. RotatoCAM only writes a G-code file; it does not run your machine, and its output is only a suggestion you must verify. CNC mills, lasers and plasma cutters are dangerous. You alone are responsible for inspecting every program, air-cutting first, and operating safely. Provided AS-IS, with no warranty.
🆕 New in 0.69.2.223.18: safe rapids everywhere, a chuck support guard, and two new controllers. A customer's video caught a rapid crossing uncut stock on its way to the next cut: legal at both endpoints, wrong in the middle. Every posted program now raises Z to Safe height first, travels high, and plunges last, on every controller, for every rapid. Programs that already retracted before hopping come out byte-identical. Safe Z over a square billet clears its spinning corners: retracts used to be figured from the model inside the blank, which could put a "safe" height inside an oversized block; they now clear the corner the billet actually sweeps. Simultaneous rotary moves are never simplified into different moves: point reduction at export could replace two safe combined X/rotary sweeps with one chord that dips; blended runs now keep their exact points. Chuck support guard: give it a length and a core diameter in Stock setup and cutting near the chuck is held out to a support nub you part off after the job, shown honestly in the sim and the backplot. FluidNC and RosettaCNC get named posts (both prototyped with customers running them, both experimental: air-cut first). FluidNC is grbl-flavoured with G93 rotary and Z-first rapids; RosettaCNC is Fanuc-flavoured RS-274 whose post pins RTCP off with G49, because RotatoCAM output is already fully resolved machine motion. Bought Pro while running this free edition? Help now walks you to your account downloads page, offline activation explains its two-step process, and both note that EXPERIMENTAL in the title bar is the beta label in every edition, licensed or not. (From 0.69.2.223.17: a 3+1 safety fix and Makera Carvera support. The indexed 3+1 strategies protected the part with cross-sections sampled at each cutting depth - and a feature living entirely BETWEEN two depths, like an impeller blade's curved top, was invisible to that, so the cutter could sweep under it at full depth. Found on a customer's part, measured at a full tool radius of intrusion, fixed at the root: the keep-out is now a ray-cast height field asked everywhere. If you cut sculpted or organic parts in 3+1, take this update. Makera Carvera: a native post for the whole family (C1 / Air / Z1) plus machine presets, following the Carvera Community Profiles conventions, rotary letter pinned to A, programs saved as .cnc - contributed as a community handoff, thank you ExaltedRaddix. Plus: export extension follows the controller (.ngc for LinuxCNC), and 3+1 work survives model slices the mesh library refuses to repair.) *(From 0.69.2.223.15: An accurate rotary drop cutter for every wrapped strategy. Each rotation angle now casts a dense lateral band of rays reduced through the tool's true profile: on the ball-on-sphere closed form the error drops from ~0.15 mm into the hundredths, and a tapered cutter rests on its actual cone instead of being planned as its shank. Cut radii move slightly outward, never inward. Roughing leaves its allowance perpendicular to the part, so 0.5 mm on a shoulder is 0.5 mm, not 0.36. The sim playback stopped lying twice over: the on-screen cutter now rides the cut surface instead of orbiting through the billet as the chuck turns, and tracks the real machine Y across a clocked 3+1 face. One Path switch now governs every toolpath line in the app — lit means lines on screen, off means a clean cutter-and-material view, instantly both ways. The log panel can be hidden from Settings. (From 0.69.2.223.14: Safe Z became a clearance above the STOCK SURFACE — it used to be measured from the rotary axis, so on a part of any size the number was nonsense: set 10 mm on a part with a 14 mm radius and your retract was 4 mm inside the material. It is now a clearance above the stock surface — type 10 and the tool pulls up 10 mm clear of the work, and the exported file says
Z10too. The change can only ever raise a retract, never lower one. Header comments a controller can actually parse: the lines at the top of the program ran past grbl's 80-character line buffer and, on posts whose name contained brackets, put brackets inside brackets, which ends a comment early so the rest of the line is read as G-code. A dry run reportederror:11, error:2, error:11, error:2and never got past the header. Fixed for every post at once. A new install now opens in the plain light theme, looking like an ordinary desktop application; the dark, CRT green and amber themes are all still under Settings. Mill / Laser / Plasma moved to Settings ▸ Machine mode, behind a confirmation, because it sat next to Controller and one stray click silently hid every rotary strategy including 3+1. Feeds for tapered and V cutters were far too fast — chip load was sized off the shank rather than the tip that is actually cutting. Plus a HolzProfi CNC6090 / HC-204A post, a rotary-letter picker that greys out when the controller only speaks one letter, and an opt-in out-of-travel check that stays silent until you tell it where your work zero is. From 0.69.2.223.13: a rotary mounted along Y now works — the new Rotary runs along setting rotates the emitted program a quarter turn so the part's length comes out on Y, a true rotation rather than an axis swap, so nothing is mirrored. And the app tells the update feed which version it is, the version string and nothing else. From 0.69.2.223.12: the simulator no longer eats the part when the cutter works near the rotary axis — a 3+1 job on a part with openings on the centreline could come out of the sim as a thin pin down the middle while the G-code was correct the whole time. Tapered cutters are planned as the shape they are — choose taper as the tool type, give it an included angle and a tip diameter, or a corner radius for a tapered ball nose, and pass spacing solves your scallop against the real cutter profile. The AtomStack C4 Pro is supported, its rotary treated as a real fourth axis in plain degrees rather than a substituted Y, with absolute angles past a full turn preserved. There is a French option for the safety gate and the getting-started guide, under Settings ▸ Language. The bundled example projects open — nine models and eighteen ready-to-run job sheets were inside every download all along, but the portable build looked for them one folder too high. And a square billet is checked as a square billet, on Y and Z one axis at a time.) Bug reports welcome at therealrevjmoney@gmail.com.
- Free Community Edition — grab the portable Windows zip from Releases (unzip and run, no install, no admin rights), or from https://rotatocam.com/
- RotatoCAM Pro — all strategies + conversational (no-CAD) programming + a built-in 4-axis G-code viewer (RotatoVIEW): https://rotatocam.com/
New to rotary CAM? A quick How-To (load → pick a strategy → Generate → Simulate → Export) lives at https://rotatocam.com/#how-to and in the app under Help → Getting started. Bundled example projects (fluted columns, a camshaft, engraving) open from Help → Open example projects….
- Simultaneous 4-axis rotary surfacing — spiral finishing + radial roughing straight from an STL or STEP solid, around the C axis
- Wrapped rotary engraving — system-font text or DXF/SVG wrapped onto a round bar with a real V-bit profile
- Flat 2D engraving — multi-line text and drawings on a plane
- STL & STEP/STP import — load meshes or CAD solids directly (solids are tessellated and scaled to mm)
- Verify before iron — 3D backplot, a feed/units check, and a deviation-colored material-removal simulator with a machining-time estimate
- Posts: grblHAL, GRBL (3018 / 3040), Genmitsu / SainSmart (4040-PRO, 3030 PROVer MAX — grbl 1.1f with a real 4th axis), FluidNC (ESP32, Z-first rapids, experimental), AtomStack C4 Pro (native A axis in degrees, experimental), HolzProfi CNC6090 / HC-204A (4-axis linkage, rotary about machine Y, experimental), Makera Carvera (C1 / Air / Z1, experimental), LinuxCNC, Mach3 / Mach4, Centroid (Acorn / Oak), MASSO G2/G3 (experimental), RosettaCNC (RTCP off, experimental) — plus drop-in custom posts (add your own controller from a folder, no rebuild) · mm / inch output
- Portable — Python and every dependency bundled; nothing to install
| Community Edition — Free | Pro — $49 | |
|---|---|---|
| Price | Free forever | Pay once per major version (no subscription) |
| Strategies | 4-axis finish (spiral) · 4-axis rough (radial) · flat 2D engrave · wrap engrave | Everything in CE, plus raster + axial/flow finishing, helical roughing, 3+1 indexed surfacing, pencil cleanup, V-carve, the full conversational suite, adaptive roughing, and laser/plasma 2D cutting |
| Safety + setup workflow, backplot, simulation | ✓ | ✓ |
The free edition is genuinely useful on its own — take a rotary part from model to verified G-code. Pro unlocks the deep toolbox: https://rotatocam.com/
64-bit Windows 10/11 · 4-core CPU · 8 GB RAM · a GPU with OpenGL 3.2+ (integrated is fine) · ~2 GB disk.
RotatoCAM Community Edition is free to download and use (closed-source freeware). The full terms are shown in the app under Help → About and ship with the download.
Website · downloads · Pro: https://rotatocam.com/ · Contact: therealrevjmoney@gmail.com Built in Myrtle Beach by Rev. J. Money.