How do I set up a 2D Pocket Toolpath on a rotary spindle in VCarve Pro & Aspire?

2D Pocket Toolpath on Rotary/Spindle Work

The 2D Pocket Toolpath creates flat-bottomed recesses (decorative panels, recessed bands) that wrap around the cylinder. It works in VCarve Pro and Aspire.

How It Works on a Rotary

The pocket toolpath is calculated in flat 2D space, and a wrapped post-processor then converts the moves along the wrapped axis into rotational degrees. In the flat 2D view the toolpath looks normal. To see it wrapped around the blank, click the Auto Wrapping button on the View Toolbar; click it again to return to the flat view.

Setting Up the Vectors

Draw the pocket boundary vectors in the 2D workspace as you normally would for flat work:

• For panels or recessed areas: draw closed rectangles or shapes within the workspace. The Pocket toolpath only works on closed shapes; open lines cannot be pocketed.
• Snap to the wrapped boundaries (the top and bottom edges of the workspace when the cylinder rotates around X) to ensure clean seam alignment.
• For cove rings that run around the cylinder: the official tutorial draws the cove lines along the wrapped axis, snapped from one wrapped boundary to the other, and cuts them with the Profile toolpath, not the Pocket toolpath. In the tutorial example the coves sit 1 inch from the job boundaries, leaving the middle of the design for flutes.

Start Depth vs. Cut Depth

• Start Depth: how far below the surface the pocket begins (0 for surface pockets, deeper if starting inside an already-roughed area)
• Cut Depth: the depth of the pocket from the Start Depth

For a spindle that has already been 3D roughed, set Start Depth to match where the roughed surface ends to avoid air cutting.

Pocket Strategies for Rotary

• Offset: cuts inward in contour-parallel passes, a good choice for smooth recess walls
• Raster: parallel passes, a good choice for flat-bottomed rectangular recesses

Projecting 2D Toolpaths onto the 3D Model

If you add 3D clipart or a 3D model to a rotary job, flat 2D toolpaths can be projected onto the 3D surface. Enable Project toolpath onto 3D model in the toolpath form and recalculate. Without it, the flat pocket ignores the 3D model surface and cuts at the wrong depth. The option is only available once a 3D model has been defined.

Wrapped Toolpath Visualization

After calculating, use the Auto Wrapping button on the View Toolbar to see the wrapped view. The official documentation notes that the rotary simulation is not 100% accurate: round holes appear oval in the wrapped view but are round when actually machined.

Saving with the Correct Post-Processor

When saving rotary toolpaths, choose the wrapped post-processor for your machine. Wrapped post-processors are added to your machine in Save Toolpaths, Manage machine configuration, then the + button under Associated Post-Processors. A wrapped post-processor converts the moves along the wrapped axis into rotational degrees.

Common Mistakes

• Using the wrong post-processor, which outputs flat XY moves instead of rotational
• Not projecting 2D toolpaths after adding 3D clipart, which gives wrong depths around the 3D model
• Pocket vectors extending past workspace boundaries (check snapping)
• Trying to pocket an open line (use Profile for lines)