How do I create advanced rotary 3D projects in Aspire: spiral fluting, barley twists, wrapped 3D models, and level wrapping?

Overview

Rotary (4th axis) work goes far beyond simple text on a cylinder. This guide covers the advanced techniques in the official rotary chapters: spiral fluting with the wrap calculation, barley twist and rope spirals with the Wrapped Spiral Layout gadget, wrapping a 3D design with level wrapping, tapered columns, turned shapes with Two Rail Sweep, importing full-3D models, and the toolpath strategy. They are used for turned columns, balusters and decorative spindles. Rotary wrapping is available in both VCarve Pro and Aspire. The 3D modeling tools used here (Two Rail Sweep, Vector Unwrapper) are Aspire only.

Setting Up a Rotary Job

1. Create a new job and set Job Type to Rotary
2. Specify the material block diameter and length, the direction of the rotation axis (along X or Y), and where Z Origin is (the surface of the material or the center of the cylinder)
3. Click OK

The 2D workspace represents the unrolled surface of the cylinder. Along the rotation axis it is the length of the cylinder, and across it is the circumference (one full rotation).

Auto Wrapping button: switches between the flat 2D view and the wrapped view of the cylinder. Toolpaths are calculated on the flat layout and the wrapped view is for visualization.

Spiral Fluting: the Calculation That Matters

Spiral flutes need vectors that extend BEYOND the 2D job boundary at an angle. When the toolpath is wrapped, the part that goes past the edge continues around the other side of the cylinder, which makes the spiral.

Calculating the Spiral Vector

For a flute that wraps N times:

1. Choose Draw Line/Polyline and draw a horizontal line at the bottom of the job (only along the part of the length you want spiralled, if not all of it)
2. While the tool is active, type 90 in the Angle box and **y N in the Length box, where y is the height of the 2D workspace (the circumference) and N is the number of wraps. Press =* to calculate.
3. Click Add to add a vertical segment
4. Draw a line that connects the horizontal and vertical lines to form a triangle, then delete the horizontal and vertical lines. The remaining sloped line is the spiral vector.

Example: with a 2.75 inch diameter cylinder the circumference is about 8.64 inches. For 3 wraps the vector length is about 25.9 inches, which the y * 3 formula calculates for you.

Several Evenly Spaced Spiral Flutes

1. Create one spiral vector
2. Use Copy Along Vectors or Array Copy to make evenly spaced copies, spaced at the circumference divided by the number of flutes
3. The first and last copies land on the same wrapped boundary, so delete one
4. Apply a Fluting toolpath (or Profile) to the spiral vectors

The Wrapped Fluting Layout gadget (Gadgets menu) lays out the flute vectors for you. It does not create toolpaths itself. You specify how many flutes to make and how far from the start and end they begin and end, and the flutes are spaced evenly around the circumference. If you choose coves at the ends, extra vectors are made that you machine with the Profile toolpath and the Machine Vectors On option. Then use the Profile or Fluting toolpath on the vectors.

Barley Twist and Rope Spirals

The Wrapped Spiral Layout gadget is for spirals (rope or barley twist) on a rotary workpiece. It does not create toolpaths directly. It lays out vectors in the 2D view for a Profile toolpath.

1. Open a rotary job and choose Gadgets > Wrapped Spiral Layout
2. Set the number of strands and how far from the start and end of the workpiece they start and end. The strand ends are spaced evenly around the circumference.
3. Control the spacing during spiralling with either Spiral Pitch or Spacing between strands, and choose a right-hand or left-hand twist
4. If you want coves at the ends, extra vectors are created for them
5. Click OK. The gadget reports how many revolutions each strand makes, and the vectors appear in the 2D view.
6. Create a Profile toolpath using the Machine Vectors On option for the spirals and coves

The vectors extend beyond the 2D job boundaries. That is expected, and the wrapping feature turns them into spirals.

Level Wrapping: a 3D Pattern Wrapped Around a Column

Level wrapping wraps a design around a column, for example a ribbon spiralling around it. Wrapping is available for rotary jobs only.

How to enable it: right-click the Level in the Component Tree and choose Wrapping.

Spiral band workflow: the basic idea is the same as the spiral vector above. Create a horizontal strip with your pattern, then wrap it like a ribbon:

1. Make the boundary lines of the strip using the angled line described above (for example y * 4 to wrap four times)
2. Make the pattern component (the Create Texture Area tool can tile a design into a component that fills the job, and Set Size can resize it to the strip)
3. Rotate and move the component to fit between the lines
4. Move the component to a Level and turn wrapping on for that Level

Twisted shapes: the official chapter combines level wrapping with the Vector Unwrapper tool and Two Rail Sweep. Unwrap a cross-section (for example a star), make rails that spiral when wrapped, sweep the cross-section along them in a separate single-sided project (because the rails extend past the job boundary, the sweep would otherwise be cropped), import that component into the rotary job, put it on a new Level and enable wrapping.

Tapered Columns

1. A zero plane component is added automatically for rotary jobs. Double-click it to open Component Properties.
2. Enter a Base Height (the example uses 0.8) and tick Tilt
3. Click the Set button in the Tilt section, switch to the 2D view, and click in the middle left and then the middle right. Set the angle (the example uses 3 degrees).
4. Adjust the modeling plane in Material Setup by moving the slider down until the Gap Inside Model is 0, so the body is not inflated

Distortion compensation: clipart in the narrower parts of a tapered column becomes distorted. Stretch the components in the wrapped dimension to compensate. The same distortion applies to toolpaths: wrapped toolpaths match flat toolpaths only at the surface of the blank, and the closer to the rotation axis (the deeper) the toolpath, the more it differs.

Turned Shapes

Turned shapes need a profile vector and Two Rail Sweep:

1. Create a rotary job
2. Draw or import a profile vector (the chapter uses a chess pawn)
3. Open Two Rail Sweep. A rotary job creates a special layer called "2Rail Sweep Rails" with two blue lines at the sides of the job, perpendicular to the rotation axis. Select both rails and click Use Selection.
4. Select the profile vector and click Apply, then check the 3D view

To model a cross-section such as a hexagon column instead, use Vector Unwrapper: it turns a cross-section vector into a profile vector for Two Rail Sweep.

Importing a Full-3D Model into a Rotary Job

To bring a full-3D model (such as a table leg) into a rotary job, import it with Import a Component or 3D Model, and use the rotary import window. The Center Model option moves the model's bounding box center to the datum, which is particularly useful if you plan to unwrap a model for rotary machining. See the official chapters on importing external models in a rotary project for the full steps.

Toolpath Strategy for Rotary 3D (a suggested order)

1. Rounding pass: the Create Rounding Toolpath gadget machines a rough blank, round or square, to a finished diameter and creates the toolpaths directly. When toolpaths are output through a wrapping post-processor, set the Z origin in job setup. The gadget's guidance is to use the Center of Cylinder for consistency when you are rounding a blank.
2. Cove cuts: a Profile toolpath on the cove vectors with the Machine Vectors On option
3. Flute cuts: a Fluting toolpath, which can ramp the cut at the ends to taper it
4. 3D surface: 3D Roughing and 3D Finishing with a small stepover for wrapped 3D models