Revolve
Use Revolve to turn a section around a line. Select the region or regions to revolve, press R, then pick the axis in the viewport. Anything with a round cross-section, such as a knob, a pulley, a bottle or a wheel, is a section plus an axis, and drawing the section is nearly always less work than drawing the thing.
The section goes on one side of the axis
This is the rule that makes revolves work, and the one that produces the error when they do not. Your profile has to sit entirely on one side of the line it turns around. A section that straddles the axis would have to pass through itself, and there is no single solid at the end of that.
Touching the axis is allowed. A profile whose edge lies exactly on the line is fine, and that is how you get a solid with no hole down the middle. Crossing it is not, and the feature says so:
Profile crosses the revolve axis — profile must lie on one side
That sentence stays in English whatever language the editor is set to. Move the profile off the axis and it goes away.
The axis is a pick
The Axis row is not a number. It is a picker: click the row, then click what you want in the viewport. Four things can be an axis:
| Pick | Notes |
|---|---|
| A straight model edge | Must be straight. A circular edge is refused, because the edge has to be a line |
| A line in a sketch | Usually the construction line you drew in the profile's own sketch, which is the axis most revolves want |
| A reference axis | The datum feature, which is the stable choice when nothing in the model happens to lie where you need |
| A world X, Y or Z axis | Through the origin |
Nothing is proposed for you. A new revolve is not born spinning about world Z: the Axis row starts empty unless the axis was already in your selection when you pressed R, and until you answer it the step sits grey in the timeline — a question, not a failure. The popover asks for the empty rows one after the other, so a revolve made with nothing selected asks for its regions first and arms the Axis row the moment they are in.
Edges of the revolve's own preview cannot be picked. The tool refuses geometry it made itself, so pick an edge that existed before you opened it — and if you click something bent, it says a revolve axis has to be a straight line rather than quietly taking it.
While the picker is running the viewport belongs to it, and the hint banner names the three keys it answers to: ↵ keeps the picks and leaves, Esc puts back whatever the row held before you started, and c empties the row without leaving. The Axis row takes one pick, so a click on something valid finishes it by itself.
Angle and direction
Angle goes up to a full turn: anything from just above zero to 360°. Under a full turn the solid is open at both ends, and those two flat faces are real faces you can select afterwards. At exactly 360° there are none, because the surface closes on itself, so a full revolve leaves no end caps to fillet later.
Direction decides where the angle is spent. One direction sweeps forward from the section's plane. Symmetric splits the angle evenly either side, which is the one to reach for when the section sits in the middle of the shape it describes.
What comes out
One region gives one solid. Several regions give several, fused together into one body. A region with an unselected region inside it comes out with a hole, exactly as an extrude would, so a washer is one revolve rather than two and a subtraction.
Combine works as it does everywhere. A revolve set to subtract is named Cut Revolve in the timeline, an add carries a Fuses with row naming the bodies it joins and becomes a new body when there are none, and new body always makes one. Pick the body to cut from whenever you set Combine to subtract — and if that cut leaves the body in two pieces, you get a body per piece, the biggest one keeping the target's name and colour.
See also
- Sweep: a path you point at instead of an axis
- Helical Sweep: around an axis and along it at once
- Regions and Profiles: the sections it turns