Helical Gear Generator
Generate a helical gear as an STL mesh. Select the module system, teeth, pressure angle, helix angle, direction and height. Angled teeth engage progressively, but the supports must accommodate axial force. Check the mating geometry and printed fit before using the pair.
What the helical generator builds
Helical teeth are inclined to the shaft axis. Their gradual engagement can reduce abrupt tooth loading, but actual sound and smoothness depend on geometry, alignment and manufacture. The helix also creates axial force. This generator supports radial/transverse and normal module systems plus the helix direction. The selected system matters when comparing diameters. KHK gear calculation reference explains the geometry.
Match the system and the helix hands
For parallel shafts, match module system, pressure-angle definition and helix-angle magnitude, with opposite hands. In the transverse system, pitch diameter is mₜ × z. In the normal system it is mₙ × z / cos β. The module guide explains the distinction. The simple spur calculators do not calculate a helical working center distance.
At 15 degrees, a normal-module gear has a pitch diameter about 3.5 percent larger than an equal-number transverse-module gear. This conversion is not a measured performance improvement. Save the module system and hand with the configuration, and check profile shift, contact and the mounting distance for the pair.
Inspect the model and the print
The 15 degree example is a starting configuration rather than a universal printing recommendation. Inspect flank overhangs, seam placement and layer geometry in the slicer. Choose support strategy and material from the actual part and intended use, then check an unloaded pair. The gear printing guide explains what to record.
A herringbone gear combines opposing helices and can balance their axial force components in a symmetric, evenly loaded pair. It still requires careful alignment and a workable assembly path. Neither tooth form replaces support designed for the application; generating a mesh does not measure noise, wear or durability.
Frequently asked questions
Are helical gears better than spur gears for 3D printing?
Helical engagement can be smoother, but it produces axial force and adds alignment and printing considerations. Choose it for the actual shaft layout and test the pair. This page does not report a measured noise or durability comparison.
How do I make two helical gears mesh?
For parallel shafts, match the module system, module, pressure-angle definition and helix magnitude with opposite hands. Check working center distance, face alignment and interference. Shared parameters are not a physical assembly test.
What does the helix angle do to the gear size?
In the radial system the pitch diameter stays module times teeth, unchanged. In the normal system the diameter grows by one over cosine of the helix angle, so a 15 degree normal-system gear is about 3.5 percent larger than its spur equivalent.
Can I print helical gears without supports?
Some configurations and orientations can print without supports. Inspect the actual layers and overhangs in your slicer. Avoid support scars on working flanks, but do not assume every allowed input is support-free.