Vent a panel with slots or honeycomb

Slots, holes or honeycomb through any panel — and why bar width is the number that decides whether it prints.

Anything with a regulator, a motor or a speaker in it needs holes, and cutting them one at a time is a job nobody finishes. The Vent shape is the whole field of openings in one object, already spaced out and already kept clear of its own edges.

A vent is a bundle of holes, not a perforated plate. What you drop is every opening at once; the bars between them are not part of the shape, they are what survives when you subtract it. That is why it arrives red, and why nothing at all happens until you cut it out of something.

Two numbers set the third. The opening is the spacing minus the bar width, so those are the only two you steer. Raise bar width and the openings narrow; widen the spacing and they grow, and the count changes to suit. Set bar width at or above the spacing and there is no opening left to cut, so it is held at a hairline instead — if a vent comes out looking like a solid block with scratches in it, that is what happened.

There is no count field, and that is deliberate. How many openings fit comes out of the width, the height and the spacing, and every opening stays a full bar width clear of the panel edge, so the field always has a border holding it together. Want more slots? Widen the area or tighten the spacing. A very large area at very tight spacing stops at 48 openings per axis rather than trying to cut ten thousand holes.

Bar width is a printed wall. Two nozzle widths — 0.8 mm on a standard 0.4 mm nozzle — is about the floor. Below that the slicer either drops the bar entirely or lays a single fragile line, and a grille made of single lines snaps when you pick the part up. This is the number to raise when a vent looks right on screen and prints badly.

Honeycomb sits flat-topped, so the roof of each cell is a short flat bridge; slots and round holes are arched over instead. Through an upright wall all three print without support at sensible sizes, and the print preview overhang tint is the fast way to see which one your particular panel likes before you commit.

Overshoot the wall. Depth has to carry the tool clear out the far side, exactly as a channel does. A vent stopping flush with the surface leaves a skin over every opening — and on a honeycomb that is a hundred of them to clean out with a knife.

1. Add a Vent from the Panels group — like a screw hole it drops in translucent red, because it is a cutter and not a grille.
2. Pick a Pattern in the Properties panel: Slots for louvres, Grid for round holes, Honeycomb for hexagons.
3. Set Width and Height to the area you want covered, and Depth so the tool passes clean through the wall and out the far side.
4. Set Spacing and Bar width. Spacing is centre to centre, bar width is the material left between openings, and the opening is whatever is left over — so bar width has to be the smaller of the two.
5. The tool cuts downward through Z, so rotate it 90° about X to face an upright wall; the slots stand upright with it.
6. Select the part first, then the vent, and Subtract.
7. Run the print check — bar width is a printed wall like any other — then export.