Most rules are based on two geometries. First we will look at all possible geometries that one can use in rules.

 

Geometries

These are all possible geometries that one can use in rules:

• point

• line

• circle

• plane

• spline

• ellipse

• cylinder

• helix (diagrid)

• cone

• torus

• sphere

 

Each element that we draw consists of a collection of geometries.

A rectangular plate consists of the following geometries (we call these sub-geometries of the plate):

• 8 points

• 12 lines

• 6 planes

 

If the plate has holes or saw patterns, then of course the plate has more sub-geometry. One can also use these sub geometries in rules.

 

Rules

A rule defines the relation between two (sub) geometries.

A rule can be set both between 2 sub-geometries of the same element or between 2 different elements.

We look at each type of rule and give an example.

 

Parallel

Example:

• 2 parallel planes: 2 sides of a plate parallel to obtain a rectangular plate.

• A plane parallel to a line

 

Coincident

Example:

• A plane flat on another plane: The bottom plane of an end plate on the upper cut plane of a column

This rule can also been used between a cylinder and a plane, a cylinder and a point,…  Cylinders appear when we use rules on round tubes or bended profiles.

 

Perpendicular

Example:

• Perpendicular planes: to obtain a rectangular plate

 

Concentric

Because the centre point of a circle or the centreline of a cylinder are not visible, this rule exists to put circles or cylinders on each other.

 

Tangent

This rule can be used only in the following combinations:

Line or plane tangent with circle or cylinder

 

Equal radius

This is a useful rule to reduce the number of dimensions. For example a plate with fillets. One needs to set the radius of only one circle or cylinder, and with this rule all radius can be set equal.

 

 

The following rules are dimensions. Further in the manual it is explained how and when the values can be adapted.

Distance

This dimension is placed between two (sub) geometries.

Pay attention that this dimension is automatically also a parallel rule: we cannot, as it happens, define the distance between two geometries if they are not parallel. It would be therefore superfluous to make two planes or a plane and a line parallel when there is already a distance between them.

 

Angle

This dimension is placed between two (sub) geometries.

To place an angle can be time-consuming, for this reason we recommend to add only an angle dimension if there is no other possibility: If you can obtain the same result without angles, then execute it without angles.

 

Radius

With this dimension you can set the radius of a circle or a cylinder.