Advanced Boolean Operations and Complex Subtractions

A nested Boolean is a Boolean operation performed inside an existing group. Example: create a box (solid) → subtract a cylinder (hole) to create a tube → then subtract a smaller cylinder to create a threaded-recess feature inside that tube. Each operation builds on the previous result. Professional 3D models commonly require 5–15 nested Boolean operations to produce a single component.

An array is a set of identical features repeated at regular intervals. Creating a ventilation slot array: (1) Model one slot as a Hole shape. (2) Duplicate it (Ctrl+D) and move it by the repeat distance. (3) Repeat for all instances. (4) Select all Hole shapes + the solid and Group. Professional tip: calculate spacing before placing. If you want 5 slots in 100mm with equal gaps: (100mm ÷ 6 spacers = 16.7mm between each).

A shell operation creates a hollow body from a solid: outer box minus inner box = hollow shell. At Grade 6, shells become more complex: lids, snap-fit joints, and interior features. Lid tolerance: for a press-fit lid, the lid outer dimension must be 0.3–0.5mm smaller than the box inner dimension. This is tight enough to hold but loose enough to remove.

A chamfer is a beveled (angled) edge. A fillet is a rounded edge. Both serve functional and aesthetic purposes: (1) Remove sharp edges that could cut users. (2) Reduce stress concentration at corners (stronger parts). (3) Improve print quality — sharp external corners at 90° sometimes print slightly rough; fillets print cleanly. In Tinkercad, fillet a corner by subtracting a cylinder from a box corner. Chamfer by intersecting a rotated box.