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How to: cut holes and pockets

Cutting is not a separate tool. You add a shape and set its Operation to Subtract (Cut), and it removes itself from everything above it in the tree.

Because the cutting shape stays in the tree as an editable entry, you can change a hole's diameter later by selecting it and retyping a number.

A round hole

  1. Create > Cyl to add a cylinder
  2. Position it so it passes through the material — with G in the viewport, or by typing coordinates in the Active Property Editor
  3. With the cylinder still active, set Operation to Subtract (Cut)

Make the cutter longer than the material. A cylinder whose end sits exactly flush with a face is a coincident-surface case, and coincident surfaces are where boolean operations in any kernel are least reliable. Overshoot on both sides. Nothing about the result changes; the robustness does.

A shaped pocket

For anything that is not a circle:

  1. Select the face you want to cut into
  2. Create > on Face
  3. Draw and constrain the outline — see How to: turn a sketch into a solid
  4. Apply
  5. Select the Sketch Surface entry, set Extrude Height to a negative value — this pushes it into the material rather than out of it
  6. Set Operation to Subtract (Cut)

To make it a through hole rather than a pocket, use a negative height larger than the material is thick.

Many holes at once

Do not create the same hole ten times. Cut one, then pattern it:

  1. Cut the first hole, as above
  2. Modify & Pattern > Array (linear) or Circ (circular)
  3. In the Property Editor, set the pattern's Target to the cutting shape — with Pick Target from the list, or Pick Target in Viewport
  4. Set the count and spacing
  5. Set the pattern entry's own Operation to Subtract (Cut) as well, so the copies cut too

Changing the original hole's diameter afterwards changes every copy, because the pattern refers to the entry rather than to a copy of its geometry.

The Independent toggle decides whether the pattern's transform stacks on top of the source shape's transform or replaces it. If a pattern lands somewhere unexpected, that is the setting to look at.

Rounding the edges of a hole

  1. Selection Mode > ENTER Selection Mode
  2. Set the selection type to edges
  3. Click one edge of the hole, then Ctrl+click an edge further round it — the shortest path between them is selected in one go, and the path is previewed while you hover
  4. Modify & Pattern > Fillet, then set the radius

For a hole's rim this is usually two clicks rather than eight.

Variable radius: once Fillet has targets, the Property Editor lists each edge with a Use Default / Custom toggle. Only the edges you set to Custom get their own radius.

Order matters

A fillet applied before a boolean rounds the shape as it was then; the same fillet after rounds the result. These are different models, and the tree cannot be reordered — see The Feature Tree and parts.

The practical rule: cut first, round afterwards. Rounding a hole that has not been cut yet rounds the cutter, which is rarely what you meant.

When a cut does not work

Nothing was removed. Check the Operation is actually Subtract (Cut) and that the cutter overlaps the material. A cutter that only touches the surface removes nothing.

The result looks wrong while dragging but right when released. That is Live Boolean Preview. Turn it off in Quality & Export if it bothers you; the committed result was always exact. See Quality and performance.

The cut worked, then broke after an earlier edit. A fillet or offset below it lost the face it referred to. See Troubleshooting.

See also