Axis and Point

Axis and Point sit with Plane: they are construction geometry, there to help you build the model but never part of it (SOLIDWORKS: Reference Axis and Reference Point · Fusion: Axis and Point · Onshape: Point). An axis shows as a dashed line and a point as a small cross, each with its name. Both follow what they were made from: an axis along an edge moves when the edge moves.

Making an axis#

1. Click Axis (under Plane ▾ on a narrow screen), or press ` and type axis.
2. Choose the Axis type:
   • Edge, round face or flat face: click a straight edge (the axis runs along it), a round face such as a hole or a peg (the axis down its middle) or a flat face (square to it, through its middle).
   • Two points: click two corners, sketch points or construction points. The axis goes through both.
   • Point and direction: click one point and choose X, Y or Z, such as an upright axis through the corner of a box.
   • Two planes: choose two planes. The axis is the line where they meet: Front and Right meet in the Z axis.
3. Tick Opposite direction to turn it round (a turn about it then goes the other way), and click OK.

Using an axis#

• Revolve: choose the axis under Revolve axis. It must lie in the sketch's plane, so only those axes are listed. Draw the profile on one side of it.
• Circular pattern: choose Pick for the Axis of pattern and click the axis. The copies go round it, such as the legs round the middle of a round stool that is not on the origin.
• Linear pattern: Edge or face…, then click the axis; the copies go along it.
• Transform: Edge or axis…, then click the axis to turn the parts about it, such as a lid about its hinge.
• In a sketch, an axis that runs along the sketch's plane shows as a dashed construction line to snap and dimension to; one square to the plane shows as the point where it goes through.

Making a point#

1. Click Point (under Plane ▾), or press ` and type point.
2. Choose the Point type:
   • Corner or sketch point: click a corner of a part, or a point of a sketch that is shown.
   • Middle of an edge: click a straight edge. The point goes at the middle of the whole edge.
   • Centre of a round face: click a hole or a peg near the end you want. At: The middle puts it half way along instead.
   • X, Y, Z: type where it goes, in mm from the origin.
3. Click OK.

Using a point#

• In a sketch, the point is a fixed point to snap and dimension to, like a corner of a part: start a circle on it, or dimension a line from it. It moves when the point moves.
• Up to vertex in Extrude, Revolve, Hole and Pattern can go up to it.
• An Axis can go through it (Two points, or Point and direction).

Tips#

• Hide an axis or a point with the eye in the feature tree, or right-click it and choose Hide. Click it in the view to select it.
• A point at the middle of an edge is a quick way to centre something on a board without measuring.

If it does not work#

• The two planes are parallel, so they never meet. Choose two planes at an angle to each other.
• The two points are in the same place. Click two different points.
• … does not lie in the sketch's plane. Revolve can only spin round an axis in the sketch's plane. Make the axis from two points of the sketch, or draw a construction line in the sketch instead.
• The edge (or round face, or corner) has gone. An earlier change removed it. Edit the axis or point and click again.