Geometry | Blend-Curve

Menu:

Add menu > Geometry sub-menu> > Add Blend-Curve

What to do:

The Blend-Curve is now in the graphic-area.

There are two ways to add the start-Point or end-Point of the Blend-Curve:

If you merge the start-Point or end-Point with a Line, Arc, or a different Blend-Curve [not with a Spline, however], then the:

...of the Blend-Curve become the same as the Line,Arc or Blend-Curve sketch-element with which it is merged.

What to do next:

To edit a Blend-Curve:

See Edit Blend-Curve Approximately drag-handles

- or -

A Blend-Curve is a special 2D path, frequently used to guide the path of a Motion-Point:

Blend-Curve parameters at each Point:

Use Blend-Curve to give a smooth sketch-path. See 'Smoothness'.

MechDesigner can guide a Motion-Point along a Blend-Curve and sketch-path with a Motion-Path FB

In general, it is important that the:

and the:

A Part that is constrained to move along a 'smooth' Blend-Curve sketch-path will vibrate less than if the part is constrained to move along a sketch-path that is less smooth. Lines and Arcs cannot give the same 'smoothness'.

Generally, when it is possible, and there is an advantage, guide a Motion-Point along a Blend-Curve.

Example

How:

Selection-Window

Assembly-Tree

Blend-Curven

Pointn at each end of the CAD-Line

The Blend-Curve is a child to the Part.

The default Angle, Curvature and Curvature Rate at the start-Point and end-Point of the Blend-Curve are zero.

The images to the left and above are default Blend-Curves.

When you merge the Blend-Curve with a sketch-element, the Blend-Curve matches the Angle, Curvature and Curvature Rate with the other sketch-element.

To show the Drag-Handles

Four drag-handles show: two different drag-handle types at each control-Point of the Blend-Curve.

At each control-Point, there is a drag-handle with an 'arrowhead' and a drag-handle with a 'small Circle'.

Drag-Handles with an 'Arrowhead' control the Blend-Curve's:

Drag-Handles with a 'Small-Circle' control the Blend-Curve's:

You cannot drag the drag-handles when they are green. You can only drag a drag-handle when it is blue.

Now you can drag the blue 'arrowhead'

Drag = move your mouse above the arrowhead, mouse-button-down, then move your mouse.

Rotate the arrowhead around the Point to control the angle of the Blend-Curve at the Point.

Move the arrowhead further away from the Point to increase the Velocity-Scaling factor

Move the small-circle clockwise from 90º [vertically up] towards 270º [vertically down], the Curvature increases from 0 (a straight-line) to +ve 'Large Value'

Move the small-circle counter-clockwise- from 90º towards 270º, the Curvature increases from 0 to –ve 'Large Value'