How do the Turn and Spin tools work in Aspire for creating lathe-style round components?

Overview

Turn and Spin are two related tools that create 3D components from an open 2D vector profile, like a lathe or a potter's wheel. Turn gives a rounded, symmetrical spindle-style shape. Spin sweeps the profile in a full circle to give a round component. They are good for domed medallions, coin shapes, bowls and vases, columns, knobs, shields, dish recesses, bosses and rosettes.

Note: Turn and Spin create a 3D relief component for carving on the job. They do not create CNC lathe toolpaths or control a rotary axis. The component is machined with standard 3D roughing and finishing toolpaths.

Turn vs Spin: The Key Difference

Turn rotates the profile around the line from its start point to its end point to create a rounded symmetrical shape. The profile should represent the silhouette of the shape you want, and it can run beneath the line between the two end points (which allows concave sections).

• The profile must be an open vector.
• The line joining the two end points is the axis of rotation, so both end points sit on the axis by definition.
• Think of the profile as the side silhouette of the finished form, like a turned spindle. If you sliced a vase in half lengthwise, the cut edge is the profile.
• Size comes from the profile: the distance between the end points becomes the length of the component, and how far the silhouette rises above that line becomes its radius (not its diameter).

Spin rotates the profile around its left end point to create a circular component based on the profile.

• The profile must be an open vector.
• The left end point becomes the center of the resulting shape, and the length of the profile to the right becomes the radius.
• Think of the profile as the radial cross-section of the finished shape, like a bowl from center to rim.
• Spin always uses the left end point. This may mean moving your vector to the right side of the job so there is room to spin it.

Step-by-Step: Using Turn

1. Draw an open vector profile representing the silhouette of the shape. For a doorknob, draw one side of the knob from its base to its top.
2. Make sure the start and end points define the axis you want to turn around, with the silhouette bulging above that line.
3. Select the vector.
4. Open Turn and Spin on the Modeling tab.
5. Select the Turn (Rotate) option.
6. Optionally tick Scale to Exact Height and enter the height.
7. Click Apply. The profile is turned around the axis to create the component.

Step-by-Step: Using Spin

1. Draw the radial cross-section of your shape as an open vector. For a dome, draw a quarter-circle arc with the left end at the center and the right end at the rim. For a bowl, draw the interior curve from center to edge.
2. Position the vector so its left end point is at the center where the component should appear on the job.
3. Select the vector.
4. Choose the Spin option.
5. Click Apply.

Note: if the result appears in the wrong position, the left end point was not where you intended. Press N for Node Editing to see the start node, or move the whole vector (Transform) so its left end is at the desired center, and apply again. Hover over the 3D model to read its dimensions at the bottom of the screen.

Scale to Exact Height

Both Turn and Spin have a Scale to Exact Height option. When ticked, the calculated shape is scaled so its maximum height equals the value you enter in the Height box. This is useful when the component has to fit a specific material depth or match other components in the scene. The final height can also be adjusted later in Component Properties.

Profile Design Tips

• The profile IS the shape: every bump, curve and taper in the profile translates directly into the 3D form.
• Always use open vectors. Both tools need exactly one open vector, with two distinct end points.
• Use Node Editing to smooth curves and reduce nodes for a cleaner shape.
• Keep profiles simple at first and test with Apply before committing.
• Components are surface-based relief, so undercuts are not possible. Overhanging profiles are ignored or give unexpected results.

Practical Use Cases

Building a complex rosette from several Spins:

1. Draw a small detailed profile for the inner core and Spin it (set a small height).
2. Draw a larger, differently shaped profile and Spin it at the same pivot position (the same left end point location).
3. Set the combine mode to Merge so the elements combine.
4. Repeat for further rings, using lower heights toward the outer edge.

Turn and Spin Compared with Other Tools

For help choosing between these tools, see the entry on which Aspire 3D modeling tool to use.

Combining Turn and Spin with Other Tools

• Dish and dome pattern: Spin a concave arc with the Subtract combine mode for the dish recess, then Spin a convex dome as the background with Add for a layered plaque effect.
• Compound shapes: Spin two different profiles on the same center with different combine modes, one adding the dome and one subtracting the dish.
• Texture: create a turned base component, then use Create Texture Area with a leaf or floral tile and a suitable combine mode so the texture follows the dome.
• Sculpting: Turn and Spin create mathematically regular forms. Use the Sculpting tools afterward to add organic irregularities for a hand-turned look.
• Distort a spun component to warp it into a non-circular shape (you may be prompted to bake first).
• Add details on top: Create Shape components with Merge for decorative elements, Extrude and Weave for borders, Sculpting for final refinement.

Common Mistakes

• Using a closed vector. Both Turn and Spin require open vectors.
• Forgetting that Spin pivots around the left end point, so the vector may need repositioning if the component lands in the wrong place.
• Not using Scale to Exact Height when material thickness is a constraint.
• Expecting Turn or Spin to be a substitute for rotary axis machining. They create a relief component only.

For preparing or modifying a profile (clipart profiles, node editing, joining two vectors) and a step-by-step coaster example, see the entry on preparing a vector profile for Turn and Spin.