SolidWorks Lofted Boss/Base: Creating Lofted Features in Solidworks

January 4, 2021
EngineeringClicks

Lofts are one of the four main SolidWorks features
Along with Extrudes, Revolves and Sweeps, they are used to create the majority of SolidWorks parts
The Loft Tool is very powerful but can be slightly temperamental and has a few quirks.

This is a clear a concise SolidWorks Lofted Boss/Base tutorial with multiple screenshots to guide you step by step. Lofts use two or more profiles to create shapes allowing a wide variety of solids to be made.

The Anatomy a Loft in SolidWorks

Extrudes, Revolves and Sweeps all generally follow similar principles of operation in that they use a single profile to create a shape.

Different basic features using the same base profile. L-R – Extrude, Revolve Sweep

On the other hand, Lofts work in a completely different manner because they use two or more profiles to create shapes in an entirely different way. This allows a wide variety of solids to be made, including those which would be difficult, or even impossible to create using the other three tools.

How to create a Lofted Boss/Base in SolidWorks:

Sketch your profiles. A minimum of two are required but a higher number of profiles allows you to create more complex shapes. Ideally profiles should be closed but Thin Feature Lofts can be created. The profiles should be spaced apart and this can be easily achieved by using multiple Planes.
Sketch Profiles, spaced apart
Select the Loft Feature, then choose the profiles in order. If the profiles aren’t selected in order then it’s highly likely that the Loft will fail.
Select the profiles in order

It helps to select a similar location on each profile, otherwise Lofts can become twisted, producing undesirable results, or even failing completely.

Try to select roughly the same place on each profile
Adjust the Constraints and options as required. There are many sub-options within the Loft feature that can be used to tweak exactly what is created, and to troubleshoot problems.

Using Guide Curves

When creating a Loft automatic guide curves, called Connectors, are used to guide the form between the Loft Profiles. These connectors can be modified, to a certain extent, by dragging the green connector dots around but they don’t provide the fine control that some shapes need.

In this case it is possible to manually add Guide Curves which can be used to define the shape in more exact terms. These Guide Curves should be sketched before the Loft feature is selected and can consist of 2D or 3D drawing. To be valid, each Guide Curve has to touch every Loft Profile at some point.

The Guide Curves can then be added to the Guide Curves box when creating the Loft.

It should be noted that the order in which the Guide Curves are selected can also affect the final shape that is created.

Did You Know?

As well as Lofting between closed profiles it is also possible to Loft to a single point. This can give a sharp end point that may be desirable in some models.

In the example a Lofted Cut was made between a closed profile, and a single point, giving a perfectly tapered radius cut.

SolidWorks: Lofting to a Point — Lofting to a Point

SolidWorks Loft Feature Top Tips

Lofts are a very powerful and useful tool that give you much more flexibility that the three other fundamental tools. Try to keep these points in mind when creating Lofts:

Lofts can be made with two or more profiles
Closed profiles usually work best
When creating the Loft, try to select a similar place on each profile
Guide Curves can be used if more control over the Loft shape is needed. These curves must touch every profile in the Loft

Happy modelling and rendering!