Text, Artwork and Gears
Use the INSERT group, the third on the sketch toolbar, to place the primitives you do not draw point by point: a text block, an SVG, and the gear family. Reach for it when you want a name plate, a logo or a spur gear. Each one is a single sketch entity that carries its own parameters, so it stays editable instead of freezing into a pile of lines.
Text
Two clicks draw the box the text will live in: opposite corners, dragged out like a rectangle. Then set the content, font, size in millimetres, alignment, style and spacing in the Text window. The outline updates as you type, and it extrudes like any other closed profile, engraved by cutting or raised by adding.
Because the size is in millimetres rather than points, what you type is what gets printed. Sub-millimetre strokes do not survive a 0.4 mm nozzle, so keep letter strokes above roughly one bead width. How FDM shapes your design explains why.
SVG
Insert artwork from a file or from the built-in gallery. It arrives anchored to a 4-corner construction frame. Drag any corner to scale and rotate it at once, aspect ratio preserved. Use the frame as the handle: constrain it and the artwork inherits the constraint.
Gears
A gear in Kapy is a real sketch primitive with involute teeth, not a picture of one. Two clicks make it: the centre, then a point that sets the pitch radius and which way the gear faces.
Where the numbers live
You never type a tooth count. Every gear carries two construction lines, and they are what you dimension:
| Line | From → to | What it sets |
|---|---|---|
| Pitch line | Centre → outer point | The pitch radius, and the gear's orientation |
| Module line | Off the end of the pitch line | The module m — tooth size |
The tooth count falls out of the two: z = 2·r / m, rounded. Dimension the pitch line to 20 mm and the module line to 1 mm and you have a 40-tooth gear. Halve the module and you have 80 finer ones in the same circle.
The three kinds
| Tool | Clicks | Notes |
|---|---|---|
| External gear | 2 | Teeth grow outward from the pitch circle |
| Internal (ring) gear | 2 | Teeth grow inward; the outer rim sits at r + 2.25m |
| Rack | 2 | Both clicks draw the pitch line. The module starts at one fortieth of its length; drag the end of the perpendicular module line to change it. Tooth pitch along the line is π·m |
Meshing
Two gears that merely look adjacent are not engaged. Apply the Mesh gears constraint to make it real: it forces the same module on both, keeps their pitch circles tangent, and clocks the teeth so they interlock. Drag one and it rides around the other, still meshed. It works external-to-external, ring-and-pinion and rack-and-pinion.
For a chain of them, use the Gear train: click each centre in turn and every vertex of the resulting polyline gets a gear sized so consecutive ones mesh, all sharing one module. Edit the first gear's module line to change them all. A chip between the first two shows the overall ratio, and clicking it lets you set your own. Move a gear and the chain re-solves. Delete one in the middle and the train splits in two.
Press Escape to finish the train, the same key that ends a line chain.
See also
- Circles, Arcs and Curved Primitives: the curved primitives you draw by hand
- Geometric Constraints: the mesh constraint that makes two gears real