Recently I had an interesting demo, where I was asked to model a tube with helically patterned holes. I was sure that we could do it, but I was surprised at the simplicity of it. But as I always say, everything is simple if you know what you are doing. Needless to say, the prospect was amazed at the speed with which we made his part and, I’m pleased to say, has become a customer. So, I thought I’d share this knowledge with our blog readers and I hope you find it beneficial.

Here is the image of the finished model.

To create the model, I first created the tube and placed the first hole.

Next, I created a tangent plane aligned with the center of the hole.

I then calculated the wrapped distance. By this I mean the perimeter length that I wanted to wrap the first helical curve.

In this example, I wanted the holes to wrap a quarter way around the tube. Remember that the arc length dimension (X) can be achieved by using the Smart Dimension command and selecting the length option.

Next, I created an angled line on the tangent plane, where the distance between the top and bottom of the line, equals the wrapped distance from the previous step.

I then wrapped the line, to the surface of the tube, using the Wrap Sketch command.

Note: Another way to create this curve is to use the Helical Curve command.

Now a curve existed along which I could create a pattern. I first selected the hole and then selected the Pattern Along a Curve command. To get the correct orientation of the holes, I used the Chord Length option.

Before accepting the pattern, I clicked on the Advanced Options.

I selected the Follow Using Surface and Curve Position options, and then selected the outer cylindrical face, as the surface to follow.

• Finally, I used the Circular Pattern command to pattern the results around the tube.

• 
  
• As you can see, this resulted in the correct orientation of the holes as they wrapped around the tube.

Again, knowledge of the advanced options was the key to achieving this pattern. If you need to learn about advance modeling techniques, you may want to attend one of our 3-day Advance Modeling courses. To learn more about this, and other course offerings, please visit our training page, on our website, at http://www.designfusion.ca//technical-training.html, or contact your Account Manager for details.

‍

‍