Advanced modelling of 3D rotary projects

A column with a spirally wrapped design

In this section we will show how to use level-wrapping feature to wrap a design in spiral manner around a column.

The workflow for creating spiral toolpaths has been presented in Simple rotary modelling using 2D toolpaths chapter. The basic idea involved creating a line at a proper angle to the rotation axis, that exceeded the 2D boundaries. When 2D toolpath is created based on such a line, it will be wrapped around material cylinder, creating a spiral.

This guide will build on that basic idea. The task is to create a horizontal strip with desired pattern and then wrap it like a ribbon around the cylinder.

To help with that task, it is important to create some helpful vectors first. We need to create lines, that will become boundaries of our strip. In this example the strip was being wrapped four times around full length of material. This example assumes that rotation axis is parallel to X axis.

To start, select Draw Line/Polyline  tool and draw a horizontal line in the middle of the job from left to right. If it is desired for the spiral pattern to only fill part of the cylinder length, this horizontal line should be drawn only in th desired location. While the drawing tool is still active, type 90 into Angle box and type y * 4 into Length box and pressing =. We used y * 4 formula so the strip will wrap 4 times. Then press Add button to add a vertical segment.

Now, start a new line that connects the horizontal and vertical lines, forming a triangle. Once this line is created, horizontal and vertical lines can be removed.

The line that we just created will form a center of the strip and it will be used later to position our design within strip. The 2D View have been shown below.

A line vector to be used for creating the strip

A piece of clipart used in this example

The Next step is to create a pattern. This example will use a single piece of clipart, that can be seen above.

Now we can utilize Copy Along Vectors  tool, to form a chain of clipart pieces. To proceed, activate the tool and select the component first, then select the line representing the strip while holding Shift. Make sure that Align objects to curve option is selected and use Distance between copies option. This example used distance of 3.6 inches. Once copies are created, they can be grouped, to make further manipulation easier The picture below shows the strip in the 3D view after being correctly positioned.

Flat 3D view of correctly positioned strip without wrapping

Wrapped strip in flat 3D view

As can be seen, the strip disappears as soon as it leaves the material boundaries. In order to make it wrap around, we need to create a new level in the component tree and move the strip component into it. Then right click on the newly created level and right click. From the pop-up menu select wrapping. After that wrapping will occur.

The last step is to make column endings. For that purpose third level was created, with Combine Mode set to Merge. This way the spiral pattern will be 'hidden' at the ends. A circular 3D tab clipart was placed at each end, and stretch vertically to match the job boundaries.