Using Curvature Combs to Inspect Curvature

One of my favorite ways to inspect curvature is to use curvature combs. These are graphical elements that display the amount of curvature at a given point on a sketch element. They’re fantastic for predicting problem areas in sketches, especially splines, that will be used to generate complex surfaces.

To display curvature combs for a sketch entity, simply right-click on the entity and choose Show Curvature Combs from the pop-up menu. When you do, SolidWorks will create a set of lines normal to the sketch entity at points along that entity; the longer the line of the comb, the more curvature there is at that point.

While the combs are very useful as is, they become even better more useful when you turn on the bounding curve. The bounding curve of a curvature comb makes it very easy to see even subtle changes or inflections in the curvature of an entity.



Curvature Combs with Bounding Curve off



Curvature Comb with Bounding Curve on


To turn on these helpful bounding curves, go to Tools, Options, System Options, and pick the Sketch page. On that page you’ll find a checkbox: Show curvature comb bounding curve.



It’s an option I knew I had, but I had forgotten about it until recently when I was trying to explain using Curvature Combs in an Advanced Part class. I could mentally trace the flow of the curve because I knew what I was looking at; my students had a harder time until I increased the density of the curvature combs. I then thought to myself, “Wasn’t there a way to show the flow of these curvature comb ends?” A little digging into the SolidWorks option pages and there it was! Use it and you’ll find it even easier to predict surface behaviors when created from your sketches.

John Setzer is Training Coordinator at Graphics Systems, a SolidWorks Value Added Reseller with locations across Wisconsin and Illinois. He is a regular contributor to the Graphics Systems’ blog:, your source for SolidWorks, Simulation, Data Management, & Product Communication Tips & Tricks.