Sweeps in Inventor 2008

By Michael Kelley,
MCAD Solutions Engineer
Hagerman & Company
Memphis, TN

When designing in Inventor, not all parts are straight and square. Sweeps enable designers and engineers to define complex shapes and parts in Inventor using the functionality and options within the sweep commands. We’ll discuss the types of sweeps; we'll also review profiles and curves for sweeps. After reading this article designers and engineers will have the confidence of understanding the powerful options in the dialog box of the sweep command.

Definition of a Sweep
Sweep Features are created by a profile section being swept along a path.
Additional profiles can be used as a guide rails or a surface can also be used to help shape the feature. The profile sketch and path cannot lie on the same or parallel planes.

The path can be an irregular shape or can be based on a part edge by projecting and including the edges onto the active sketch. The path can be either open or closed and can lie in a plane or lie in multiple planes (3D Sketches). Some common uses of a sweep feature are cables and pipes. A sweep feature can add or remove material from a part or solid.

3 Types of Sweeps

1) Sweep along a path

2) Sweep along a path and guide rail. The guide rail controls scale and twist of the swept profile.

Profile Scaling option

X&Y – Scales the profile in both the X and Y directions as the sweep progresses.
X – Scales the profile in the X direction. The profile is not scale in Y.
None – Keeps the profile at a constant shape and size as the sweep progresses. Using this option the rail controls only the profile twist and is not scaled.

3) Sweeping a profile along a path and guide surface. The guide surface controls twist of the swept profile.

Orientation of a Sweep

Path holds the swept profile constant to the sweep path. All sweep sections maintain the original profile relationship to the path.
Parallel holds the swept profile parallel to the original profile.
Taper - Value entered is for the angle a user wants the profile to be drafted. The default value is 0 degrees.

Optimize for Single Selection – When checked, Inventor automatically advances to the next selection option once a single selection is made. When cleared, multiple selections are required.

Summary
Traditional path sweeps are used for objects that have uniform profiles swept along a trajectory, such as gasket grooves, cabling, tubing, and piping through an assembly. Guide rail sweeps are used for features that have potentially non-uniform profiles which scale or twist while sweeping along a trajectory, such as a complex handle for consumer parts. Guide surface sweeps are used for features that have uniform profiles swept along a non-planar trajectory in which the twist of the profile must maintain a given orientation to a selected surface, such as a machining operation performed on a cylindrical part.