Revolved cut in Solidworks - Deep Dive

Overview - Revolved cut

What is it?

A revolved cut is a feature in SolidWorks that removes material by rotating a 2D sketch around an axis. It creates a cut shape that is symmetrical around that axis. This helps shape parts by hollowing or carving out areas in a circular pattern.

Why it matters

Revolved cuts let designers quickly create complex, round holes or grooves without drawing every detail. Without it, making symmetrical cuts would be slow and error-prone, requiring many manual steps. This saves time and ensures precision in product design.

Where it fits

Before learning revolved cuts, you should understand basic sketching and extrusion in SolidWorks. After mastering revolved cuts, you can explore advanced features like lofts, sweeps, and multi-axis cuts to create even more complex shapes.

Mental Model

Core Idea

A revolved cut removes material by spinning a 2D shape around a center line, carving out a symmetrical hole or groove.

Think of it like...

Imagine cutting a cake by spinning a knife around a stick in the center, slicing out a round groove evenly all around.

  Axis of Rotation
      │
      │
  ┌───┴───┐  ← 2D Sketch Profile
  │       │
  │       │
  └───────┘
   ↻ Revolve spins this shape around the axis,
   removing material in a circular pattern.

Build-Up - 7 Steps

1

Foundation

Understanding 2D Sketch Profiles

Concept: Learn what a 2D sketch profile is and how it defines shapes in SolidWorks.

A 2D sketch is a flat drawing made on a plane. It can be lines, arcs, or circles that form a closed shape. This shape is the base for features like extrusions or cuts. For a revolved cut, the sketch defines the shape to remove when spun around an axis.

Result

You can create simple shapes like rectangles or circles that will be used to cut material.

Knowing how to create closed 2D sketches is essential because the revolved cut depends on this shape to remove material accurately.

2

Foundation

Defining the Axis of Revolution

Concept: Learn how to select or create the axis around which the sketch will revolve.

The axis is a straight line that the sketch spins around. It can be an edge, a centerline in the sketch, or a reference line. This axis controls the symmetry and direction of the cut.

Result

You have a clear line that acts like a spinning rod for your sketch.

Choosing the correct axis ensures the cut is placed exactly where you want the material removed.

3

Intermediate

Creating the Revolved Cut Feature

🤔Before reading on: Do you think the revolved cut removes material by spinning the sketch 360 degrees or less? Commit to your answer.

Concept: Learn how to use the revolved cut tool to remove material by revolving the sketch around the axis.

In SolidWorks, select the sketch and the axis, then choose 'Revolved Cut'. You can specify the angle of revolution, usually 360 degrees for a full cut or less for partial cuts. The software removes material by spinning the sketch shape around the axis.

Result

A symmetrical cut appears in the 3D model, shaped like the revolved sketch.

Understanding that the angle controls how much material is removed helps you create partial or full circular cuts precisely.

4

Intermediate

Using Partial Revolutions for Custom Cuts

🤔Before reading on: Can you create a cut that only removes material over half a rotation? Yes or no? Commit to your answer.

Concept: Learn to control the revolution angle to make cuts that are less than a full circle.

Instead of a full 360-degree revolve, you can set the angle to 180 degrees or any value. This creates a cut that only removes material over that portion of the rotation, useful for grooves or partial holes.

Result

The cut appears only over the specified angle, leaving the rest of the material intact.

Knowing how to limit the revolution angle expands design possibilities beyond full circular cuts.

5

Intermediate

Combining Revolved Cuts with Other Features

🤔Before reading on: Do you think revolved cuts can be combined with extrusions and fillets in one model? Commit to your answer.

Concept: Learn how revolved cuts fit into a sequence of features to build complex parts.

You can add revolved cuts after extrusions or before fillets. The order matters because each feature modifies the shape. For example, a revolved cut can hollow out a cylinder created by extrusion.

Result

A complex part with multiple features that work together to form the final shape.

Understanding feature order helps avoid errors and achieve the desired final design.

6

Advanced

Troubleshooting Revolved Cut Failures

🤔Before reading on: Do you think an open sketch profile can create a revolved cut? Yes or no? Commit to your answer.

Concept: Learn common reasons why revolved cuts fail and how to fix them.

Revolved cuts require closed sketches; open profiles cause errors. Also, the axis must not intersect the sketch in invalid ways. If the cut fails, check sketch closure, axis placement, and angle settings.

Result

You can identify and fix errors that prevent the cut from working.

Knowing common failure causes saves time and frustration during modeling.

7

Expert

Advanced Control with Direction and Thin Features

🤔Before reading on: Can revolved cuts create thin walls by offsetting the sketch? Yes or no? Commit to your answer.

Concept: Learn how to use direction options and thin feature settings for precise control.

SolidWorks allows you to choose the direction of the cut (one side, both sides) and add thin wall thickness to the revolved cut. This is useful for creating grooves or hollow shapes with controlled wall thickness.

Result

You get complex cuts with thin walls or specific directional removal.

Mastering these options lets you create detailed and lightweight parts efficiently.

Under the Hood

The revolved cut works by taking the 2D sketch profile and mathematically rotating it around the chosen axis. This rotation sweeps the profile through space, creating a 3D volume that is then subtracted from the existing solid. The software calculates the intersection of this volume with the part and removes the overlapping material.

Why designed this way?

Revolved cuts were designed to simplify creating symmetrical cuts around an axis, which are common in mechanical parts like shafts or holes. Instead of manually modeling complex shapes, revolving a simple 2D profile is faster and less error-prone. Alternatives like manual 3D modeling would be inefficient and harder to control.

  ┌───────────────┐
  │ 2D Sketch     │
  │ Profile       │
  └─────┬─────────┘
        │ Revolve around axis
        ↓
  ┌───────────────┐
  │ 3D Revolved   │
  │ Cut Volume    │
  └─────┬─────────┘
        │ Subtract from
        ↓
  ┌───────────────┐
  │ Final Part    │
  │ with Cut      │
  └───────────────┘

Myth Busters - 4 Common Misconceptions

Quick: Can you create a revolved cut with an open sketch profile? Commit to yes or no.

Common Belief: You can use any sketch, open or closed, for a revolved cut.

Reality: The sketch must be closed to create a valid revolved cut; open sketches cause errors.

Why it matters: Using an open sketch leads to failed features and wasted time troubleshooting.

Quick: Does the axis of revolution have to be inside the sketch profile? Commit to yes or no.

Common Belief: The axis must always be inside the sketch profile for the cut to work.

Reality: The axis can be outside or inside the profile, depending on the desired cut shape.

Why it matters: Misunderstanding axis placement limits design creativity and causes unnecessary constraints.

Quick: Is the revolved cut always a full 360-degree rotation? Commit to yes or no.

Common Belief: Revolved cuts always revolve the sketch a full 360 degrees.

Reality: You can specify any angle, allowing partial revolved cuts for custom shapes.

Why it matters: Assuming full rotation only restricts design options and wastes time adjusting features.

Quick: Can you create thin-walled cuts directly with revolved cut? Commit to yes or no.

Common Belief: Revolved cuts cannot create thin walls; you must model them separately.

Reality: SolidWorks allows thin feature options in revolved cuts to create thin walls easily.

Why it matters: Ignoring thin feature options leads to more complex modeling and less efficient designs.

Expert Zone

1

Revolved cuts can use construction geometry as the axis, which is invisible in the final model but controls the cut precisely.

2

The order of features in the design tree affects how revolved cuts interact with other features, impacting the final shape.

3

Partial revolved cuts can be combined with variable angle sketches to create complex, non-uniform grooves.

When NOT to use

Avoid revolved cuts when the cut shape is not symmetrical around an axis or when the profile changes along the path. Use sweeps or loft cuts instead for these cases.

Production Patterns

In production, revolved cuts are often used to create holes for shafts, grooves for seals, or decorative round patterns. Designers combine them with parametric sketches to quickly adjust dimensions for different product versions.

Connections

Lathe Machining

Revolved cuts mimic the material removal process of lathe machines that spin parts to cut symmetrical shapes.

Understanding lathe machining helps grasp why revolving a sketch creates precise circular cuts efficiently.

Polar Coordinates in Math

Revolved cuts use rotation around an axis, similar to how polar coordinates define points by angle and radius.

Knowing polar coordinates clarifies how the sketch profile sweeps through space during revolution.

Symmetry in Art and Design

Revolved cuts exploit symmetry to create balanced, uniform shapes quickly.

Recognizing symmetry principles helps designers create aesthetically pleasing and functional parts.

Common Pitfalls

#1 Using an open sketch profile for the revolved cut.

Wrong approach:

Create a sketch with a gap and try to apply revolved cut directly.

Correct approach:

Ensure the sketch is fully closed before applying the revolved cut feature.

Root cause:

Misunderstanding that the cut needs a closed boundary to define the volume to remove.

#2 Selecting the wrong axis of revolution causing unexpected cut placement.

Wrong approach:

Pick an edge far from the sketch or an unintended line as the axis.

Correct approach:

Carefully select or create a centerline axis that aligns with the desired cut location.

Root cause:

Not realizing the axis controls the cut's position and symmetry.

#3 Assuming revolved cut always uses 360 degrees and ignoring partial angles.

Wrong approach:

Set revolved cut angle to 360 when only a partial groove is needed.

Correct approach:

Specify the exact angle of revolution to create partial cuts as required.

Root cause:

Lack of awareness about angle control in the revolved cut feature.

Key Takeaways

Revolved cuts remove material by spinning a closed 2D sketch around an axis, creating symmetrical cuts.

Choosing the correct axis and ensuring the sketch is closed are essential for successful revolved cuts.

You can control the angle of revolution to make full or partial circular cuts, expanding design flexibility.

Revolved cuts integrate with other features in the design tree, so feature order affects the final part shape.

Advanced options like thin features and direction control allow precise and efficient modeling of complex cuts.