PartDesign AdditiveHelix/ru

The Additive Helix tool creates a solid by sweeping a selected sketch or 2D object along a helix path.

The profile (B), is swept around axis (A) in order to produce the solid helix (C).

1. Select the sketch to be swept into a helix. A face on the existing solid can alternatively be used.
2. There are several ways to invoke the tool:
   • Press the Additive Helix button.
   • Select the Part Design → Additive Features → Additive Helix option from the menu.
3. Set the Helix parameters (see next section).
4. Inspect the Helix in the view window, to ensure that the parameters do not result in a self intersecting helix.
5. Press OK.

When creating an Additive Helix, the Helix Parameters dialogue offers several parameters specifying how the sketch should be swept.

Axis

This option specifies the axis about which the sketch is to be swept.

• Normal sketch axis: selects the normal of the sketch that runs through the sketch origin as axis.
• Vertical sketch axis: selects the vertical sketch axis. This is the default for new helices.
• Horizontal sketch axis: selects the horizontal sketch axis.
• Construction line: selects a construction line contained in the sketch used by the Helix. The drop down list will contain an entry for each construction line. The first construction line created in the sketch will be labelled Construction line 1.
• Base (X/Y/Z)-axis: selects the X-, Y- or Z-axis of the Body's Origin;
• Select reference…: allows selection in the 3D View of an edge on the Body, or a datum line.

Mode

This controls what parameters will be used to define the helix. The choices are:

• Pitch-Height-Angle: definition via the height per turn and the overall height
• Pitch-Turns-Angle: definition via the height per turn and the number of turns
• Height-Turns-Angle: definition via the overall height and the number of turns
• Height-Turns-Growth: definition via the overall height, the number of turns and the growth of the helical radius. So a Height of zero leads to a path in form of a spiral. A Height and Growth of zero to leads to a path in form of a circle.

Pitch

The distance between turns in the helix.

Height

The height of the helix (center-center).

Turns

The number of turns in the helix. Define as Height/Pitch

Cone Angle

Angle of the cone that forms a hull around the helix. Allowable range: [-89°, +89°].

Left handed

If checked, the turning direction of helix is reversed from default clockwise to counterclockwise.

Reversed

If checked, the axis direction of helix is reversed from default.

Recompute on change

If checked, the helix will be shown in the view, and updated automatically on every change of the parameters.

• ДанныеPitch: The axial distance between two turns.
• ДанныеHeight: The total length of the helix (not accounting for the extent of the profile)
• ДанныеTurns: The number of turns (does not need to be a whole number)
• ДанныеLeft Handed: See Left Handed.
• ДанныеReversed: See Reversed.
• ДанныеAngle: The rate at which the radius of the helix increase along the axis. Allowable range: [-89°, +89°].
• ДанныеReference axis: The helix axis
• ДанныеMode: The helix input mode (pitch-height, pitch-turns, turns-height)
• ДанныеOutside: Not used (Used in SubtractiveHelix)
• ДанныеHas Been Edited: If false, the tool will propose an initial value for pitch based on the profile bounding box, so that self intersection is avoided.
• ДанныеRefine: true or false. If set to true, cleans the solid from residual edges left by features. See Part RefineShape for more details.
• ДанныеProfile: Either a sketch containing a closed contour, or a face.
• ДанныеMidplane: Not used.
• ДанныеUp to face: Not used.
• ДанныеAllow multiple face: Not used.

Notes

Helixes are very difficult for the underlying engine to calculate correctly because the curves involved push floating point precision to its limit. Some tips for achieving robust results:

• To avoid the risk of self-intersection, the thread profile must be slightly narrower than the pitch.
• Exact matches where the surface of the helix is perfectly aligned with the surface of another object are fragile. A thread around a bolt cylinder is an example of this. Make sure the profile extends well into the bolt. 1µm has been observed to be sufficient.
• Objects created by rotation have a seam-line. The profile must be slightly offset from the seam line. You may chose one of the default planes. Or rotate the profile sketch before adding the helix. Or use the default plane, but the other half (opposite of the seam-line).
• Performing further operations on a helix like attempting boolean operations with another object can be very sensitive to small changes. When they fail, they often break the model in surprising ways. Try to make operations on a helix either clearly overlap (interfere) or clearly not overlap. It may even work initially, and then break later when objects are moved slightly.