Generate a helical gear.
Download the CAD file.
Describe a helical gear in plain English — normal module, teeth, helix angle, hand, bore and keyway — and Cadfai builds a real parametric solid you can download as STEP and STL in seconds.
A complete, mechanically valid part — ready for CAD, CAM, or 3D printing.
Involute helical teeth
Angled tooth flanks built from your module, tooth count, helix angle and hand.
Left or right hand
Specify helix direction so mating gears pair correctly.
Bore & keyway
Center bore sized to your shaft, with optional keyway.
Editable STEP solid
A real B-rep solid you can open and modify in any CAD tool — plus STL.
Mention any of these in your prompt — in words or numbers — and Cadfai applies them.
Describe it
Type the part in plain English with any dimensions you care about.
Cadfai builds it
The prompt becomes a parametric 3D solid — usually in under a minute.
Download
Grab the STEP and STL files, or re-prompt to tweak dimensions.
Copy one, or write your own.
Every model exports as a STEP file (a true B-rep solid for CAD and CNC) and an STL file (for 3D printing). STEP means you can edit, machine, and measure the part — not just print a shell. STEP vs STL →
Generate now →What file formats does the helical gear generator export?
Every helical gear is exported as a STEP file (a solid B-rep for CAD/CAM) and an STL file (a mesh for 3D printing).
Can I set the helix angle and hand?
Yes. Describe the helix angle in degrees and specify right-hand or left-hand, and Cadfai builds the matching helical tooth geometry.
Are the teeth a real involute profile?
Yes — the tooth profile is generated from your normal module, tooth count, helix angle and pressure angle for a mechanically valid gear.
Is it free to use?
You can start free. Cadfai includes free prompts to generate and download models; top-up prompts and a Pro plan are available.
Can I edit the gear afterwards?
Yes — because the output is a STEP solid you can modify it in any CAD tool, or re-prompt Cadfai with new dimensions.