Gear
A spur gear with parameters for teeth, pressure angle and bore.
Gear is a spur gear driven by parameters for teeth count, tip and root radii, bore and pressure angle.
Geometry
The topology is the same tube structure as Pipe (inner wall, outer wall, top and bottom plates); only the outer wall radius swings between the tip and root circles along the tooth profile.
Each tooth occupies one pitch (360° ÷ teeth), split into a four-segment trapezoidal profile. Tip Tooth Width is the flat tip as a ratio of the pitch, and the root width is derived from the Pressure Angle.
The pivot is at the center of the bottom face, so a gear of thickness t occupies y=0 to y=t.
Parameters
| Label | Script key | Default | Range | Description |
|---|---|---|---|---|
| Tip Radius | r1 | 1 | 0.02 ~ 1000 | Tip circle radius — the outer size of the gear, in meters |
| Root Radius | r2 | 0.8 | 0.011 ~ 1000 | Root circle radius — must stay below Tip Radius |
| Bore Radius | r | 0.3 | 0.001 ~ 1000 | Center hole (bore) radius, in meters |
| Thickness | h | 0.25 | -1000 ~ 1000 | Gear thickness in meters |
| Teeth | sides | 12 | 3 ~ 128 | Number of teeth |
| Tip Tooth Width | th | 0.25 | 0.05 ~ 0.95 | Flat tip width as a ratio of one tooth pitch |
| Pressure Angle | ang | 20 | 0 ~ 45 | Pressure angle in degrees — larger widens the tooth root |
| Height Segment | heightsegment | 1 | 1 ~ 32 | Divisions through the thickness |
Gear reinterprets the shared fields with gear terminology. The script keys are r1 (tip), r2 (root), r (bore), h (thickness), sides (teeth), th (tip tooth width ratio) and ang (pressure angle). They mean something different here than on other shapes, so read the Inspector labels.
How to create
-
Drag in empty space — the drag distance becomes the tip radius. The root radius is set to 80% and the bore to 30% of it automatically.
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Click to confirm, then move the mouse up to set the thickness.
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Click again to finish, then set teeth and pressure angle in the Inspector.
Scene view editing
The ±X and ±Z handles drive Tip Radius and the ±Y handles drive Thickness. Root Radius and Bore Radius are set separately in the Inspector — growing only the tip makes longer teeth.
Tips
Tip Tooth Width above 0.5 lets the pressure angle widen the root until the valleys nearly vanish, leaving a notched disc. Keep it at 0.2 – 0.3 for a gear-like read.
For a meshing pair, match the pitch (Tip Radius ÷ teeth) across both gears and use the same pressure angle.
A thin gear (0.05 or less) reads as a sprocket.
Script
In a script this shape is written as gear.
gear "DriveGear" r1=1 r2=0.8 r=0.3 h=0.25 sides=16 th=0.25 ang=20 @0,0,0
gear "Sprocket" r1=0.5 r2=0.42 r=0.1 h=0.04 sides=24 @2,0,0
See also — Shape Type List · Creating Shapes and Modes · Scene Script Syntax