Patterns that
arrive ready
to cut.
Geometric line art computed from real gear tooth counts, exported at true size in inches. It opens in LightBurn or Carbide Create at the size you asked for, with a node count your controller will not choke on. Or build it as native sketch geometry inside Autodesk Fusion.
From $19.99Instant download · browser $19.99, Fusion $49.99, both $59.99
Why bother
Drawing it is easy. Cutting it is not.
Plenty of things will draw you a spiral pattern. Getting one onto a machine is where it falls apart: the file imports at the wrong scale, the curve does not quite meet itself, or it arrives with two hundred thousand nodes and the controller stalls opening it.
These tools are built the other way round. Every export carries real inch dimensions. Every curve closes, because the tooth counts are solved rather than eyeballed. And you set the node count directly, with the tool telling you where you stand before you export.
Try it · free
Draw one right now.
No download, no sign-up, nothing to install. This is the real generator with some of it held back: roll the planet, move the pens, and watch the curve close.
You are watching a preview. Click it to take over.
The demo gives you one track circle, two pens, the bolt-circle and radial layouts, and 480 points per circuit. The paid version adds:
- Six-circle tracks
- Twelve pens
- The spiral layout
- Up to 40,000 points
- True-size SVG
- CSV of every point
- Layered compositions
- The offline file, yours to keep
The Fusion generator, start to finish. A track laid out in the browser tool and opened in Fusion, the run report, the pen plate, and the check that matters — it refuses a planet you could not machine, and names the setting that fixes it. Then the gears come out as cuttable profiles and the whole thing runs as a jointed mechanism, drawing the curve it just computed.
Generated on this page, just now
Nothing here is a picture file.
Every plate below was computed in your browser when the page loaded, by the same code that ships in the tools. Reload and the math runs again.
Before you choose one
Three questions worth asking.
There are free spirograph tools online and some of them are good fun. If what you make is going to a machine rather than a screen, these are the things that decide whether a file is usable, and they are easy to check before you commit to anything.
Does the export know its own size?
A drawing without a stated scale is a shape, not a part. If the file carries no real dimensions you are guessing at import, and guessing again when it comes out the wrong size.
Can the track be something other than a circle?
Resizing a ring is not the same as changing its shape. A circle in a circle gives you one family of figures, and you exhaust it quickly.
Do you control the node count?
Controllers struggle with node count long before file size. A pattern that renders instantly in a browser can stall a laser, and without a readout you find out at the machine.
Downloads
Two tools. Three ways in.
Already bought one? The current releases are Track Generator 1.3 and Fusion generator 1.0 — each tool prints its own release in its header, so you can tell at a glance whether yours is current. Updates within the release you bought are free: click your original download link again and it will re-send itself if it has expired.
Trochoid Track Generator
Release 1.3
- SVG exports carry real inch dimensions, so files land at size
- Set the node count yourself, with a readout before you export
- Tracks from one to six circles, not just a circle in a circle
- Single-stroke title block that CAM software can actually read
- CSV of every coordinate, full resolution, for plotters and scripts
- One HTML file. Offline, no account, yours to keep
Trochoid Generator for Fusion
Release 1.0
- Opens a layout saved by the browser generator — design the track there, build it here
- Curves built as real sketch splines, closed and CAM-ready
- Circle, racetrack, or any closed sketch path you draw
- Involute gear profiles with pen holes, shafts and fillets
- Clip a corner ornament out of any pattern
- TracePoint — record any point's motion from your own joints
- Whole-tooth fitting, closure solving, and geometry checks
Both together
Release 1.3 + 1.0
- Everything in both, one download
- Lay the track out in the browser, save it, open it in Fusion — one file carries it across
- The browser version needs no CAD at all — start there
- The Fusion generator takes it to geometry you can cut
- Both guides, and the planet-selection workbook
- Free updates within release 1.x of each tool
How you'd use it
Draw, solve, cut.
Set the track
Place circles and pick tooth counts, or hand it a closed sketch path you've already drawn — lines, arcs, and splines all work. Lay it out in the browser tool and the Fusion generator will open that layout and build from it.
Let it close the loop
It reports the implied tooth count, scales the layout by a fraction of a percent to make it whole, and tells you the orbits to closure.
Take the geometry out
True-size SVG for a laser or plotter, CSV for anything else, or closed splines sitting in your Fusion sketch ready for a toolpath.
Before you buy
Straight answers.
Do I need Fusion to use this?
Not for the browser version — it's one HTML file that runs offline in Safari, Chrome, or Edge. The script pack does need Autodesk Fusion, any recent version, and installs through Utilities → Scripts and Add-Ins.
Is the output actually to scale?
Yes. SVG exports carry real inch dimensions, so they import at true size into Fusion, Illustrator, or LightBurn without a scale factor. The CSV is in inches too.
What does "whole-tooth fitting" mean?
Teeth have to space evenly all the way around a closed track, which means the perimeter must be an exact multiple of the circular pitch. A track you drew by hand almost never is. The tools scale the whole layout by the small factor that fixes it — the shape is unchanged, and the planet gear is untouched.
Can I sell what I make with it?
Yes. The curves you generate are yours, commercial use included. The tools themselves aren't for redistribution.
Will these gears actually mesh if I cut them?
The tools generate pitch-line geometry and tell you when a planet is too large for the tightest curve on your track. They don't cut tooth profiles, and they don't handle profile shift — below about 18 teeth at 20° pressure angle you'll want a higher pressure angle or a shifted profile.
Make something that closes.
Pick your side of the fence, or take both and move between the browser and the model as it suits the job.