Using the Wrap Feature to Create a Barrel Cam

Let’s model together a barrel cam. Watch this video first:

The inspiration for this tech tip came from the SolidWorks Forum, where Danail Lesev was asking for help in creating a barrel cam.

The description of the cam profile is shown in fig. 1.

Fig. 1 Barrel Cam Profile

He used the correct tool for debossing the cam – the Wrap Feature, but his attempts to create the cam were not satisfactory, see fig. 2.

Fig. 2 Created CAM

The reason for that lies inside the sketch to be wrapped (fig. 3). First of all, the overall length of the sketch has to be equal to the circumference of the cylinder (55 x π); otherwise the cam will not “close around the cylindrical body. There is also a secondary issue in the way the transitions were created – too many spline points = bad curvature.

Fig. 3 The sketch is wrong

As you noticed in the video, we recreated the sketch using tangent arc and lines and fitting splines on top of them. As an alternative we could have used 2 point splines for the transition.