Enclosure side vents
20 × 4 mm slots at 26 × 8 mm pitch on a 150 × 80 mm panel are 36.8% open with 4.00 mm webs.
Hex vents for more airflow →Ventilation Slot DXF Generator
Rows of obround slots with round ends, staggered by half a pitch. Set the slot length, width and both pitches; the open area, the narrower web and the slot count update live, and the files keep the slots on the inner cut layer.
Lattice cut length · bridge · row spacing
Fills row spacing 0.6t, cut length 5t + 5 (12–60 mm) and bridge 0.8t from the thickness.
Panel size · legs · margin
- Bend zone W
- Corner zone W90
- Wrap strip
- Pattern open area
- 36.8%
- Web
- 4.00 mm
- R_min estimate
- Bend check
Inner cuts · 1stBend guides · no cutOutline · last
Too tight.
Links too thin.
Web too thin.
Cast acrylic is brittle. Acrylic living hinges crack after a few bends; use it for flat vent panels, or cut a swatch before any hinge.
Very dense. The preview draws the first 120,000 cut-outs; the numbers count every one.
Proof preview · not a cut file
Free proof
Pro · cut-ready files of this design
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Proof saved. The cut-ready version of this design is in the Pro pack below.
Readout
- Panel open area
- 19.8%
- Flat panel
- 150.00 × 80.00 mm
- Slit rows
- Hinge zones
- Top + bottom plates
- Net link
- Min link
- Cut-outs
- 31 slots
- Hole range
- 0.0–0.0 mm
- Total cut length
- 1.83 m
R_min, laser time and open area are estimates from the torsion and area models. Confirm the bend with the 5-strip swatch before a full cut.
Pro pack · built for the design above
Production Laser DXF/SVG & 3D STEP CAD Pack
Layered, de-duplicated, cut-ordered DXF R12 and LightBurn SVG with correct kerf handling, a STEP + STL solid of this hinge, and a 5-step swatch that follows your own design.
| You get | Free | Pro |
|---|---|---|
| Every pattern, live 2D/3D, W, R_min, open area | Yes | Yes |
| Proof PNG (≤ 1000 px) + formula TXT | Yes | Yes |
| Kerf-compensated DXF R12 + LightBurn SVG | — | Yes |
| STEP AP214 + binary STL solid | — | Yes |
| 1:1 swatch + datasheet PDF | — | Yes |
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Ready-made designs
Vent panels for real enclosures
Click one to load it into the studio above; every value stays editable.
How to use it
Four steps from sheet to cut file
No Generate button: every step redraws the 2D path, the 3D bend and the numbers at once.
- 01Set the vent areaPanel width, height and margin give the field the slots may use.
- 02Size the slotsSlot length and width set each obround; round ends cut cleanly and do not crack.
- 03Set both pitchesPitch X and Y set the webs; alternate rows are staggered by half a pitch.
- 04Export DXF and SVGSlots go on the inner layer with kerf compensation, the outline last.
Formula
Slot area and open area
An obround is a rectangle of (L − w) × w with a half circle on each end, so its area is (L − w) × w + πw²/4. One slot sits in every px × py cell, staggered or not, which makes the open area 100 × slot area / (px × py).
Rules
Web and edge margin
The studio reports the narrower web: pitch Y minus slot width between rows, or pitch X minus slot length along a row. It warns below max(0.8 mm, 0.4 × t), which is 1.2 mm in 3 mm acrylic. A 7.5 mm slot on an 8 mm row pitch leaves 0.50 mm and is flagged.
Slots are placed only where the whole obround fits inside the panel minus the margin. Keep the margin at least twice the web so the frame around the vent is stiffer than the bars inside it; the presets use 6 to 10 mm.
Compare
Slots vs round holes vs hex
All rows keep a 2 mm web.
| Pattern | Pitch | Open area | Character |
|---|---|---|---|
| Obround slot 20 × 4 mm | 22 × 6 mm pitch | 58.0% | Stiff along the slots; directs airflow |
| Staggered round Ø5 mm | 7 mm pitch | 46.3% | Even look; weakest per web |
| Hex vent 5 mm across flats | 7 mm pitch | 51.0% | Most open area per web |
| Hex vent 8 mm across flats | 10 mm pitch | 64.0% | Large cells, fewer cuts |
Slots trade a little open area for stiffness and direction. On a lid over a hot board, run the slots across the airflow path; for maximum airflow behind a fan, a hex vent on the perforated panel page passes more air at the same web.
Where it fits
Use cases and related tools
Real jobs makers cut with these numbers, and the tool page that fits each one.
Amplifier top covers
30 × 6 mm slots at 38 × 10 mm give 45.3% open area over a hot amplifier board.
Speaker grille generator →Single-board computer cases
A 100 × 60 mm lid with 12 × 3 mm slots is 35.5% open and keeps fingers out.
Wrap the case with a hinge box →Check a radius before cutting
Work out W and the minimum radius for any sheet with the formula explained step by step.
Kerf bending calculator →Send the file to the laser
Layer colours, cut order and import settings for LightBurn, Glowforge, xTool, RDWorks and VCarve.
DXF & SVG guide →Compare every pattern
See all 12 hinge and vent patterns with their flexibility or open-area formula before you choose.
Pattern library →Questions
Frequently asked questions
R_min values are estimates from the torsion model; confirm with a test cut.
How is the open area of obround slots calculated?
Each slot of length L and width w has area (L − w) × w + πw²/4. Divide by the cell px × py: 20 × 4 mm slots at 26 × 8 mm pitch give (64 + 12.57) / 208 = 36.8%.
Which web counts for slots?
The narrower of the two: pitch Y minus slot width between rows, and pitch X minus slot length between slots in a row. The default vent has min(8 − 4, 26 − 20) = 4.00 mm.
Why use slots instead of round holes?
Slots keep long continuous bars between rows, which stiffens the panel along the slot direction and guides airflow. At the same 2 mm web, hex holes reach a higher open area, while slots keep a stronger panel.
How close can slots be to the edge?
Only whole slots that fit inside the panel minus the margin are placed. An 8 mm margin on 3 mm acrylic keeps the edge stiff; drop to 6 mm on small lids like the computer case preset.
Does staggering change the open area?
No. Offsetting every other row by half of pitch X keeps one slot per cell, so the formula is the same. It spreads the webs so there is no straight weak line across the panel.
Same engine
The rest of the toolkit
Every tool shares one geometry engine, so numbers match between pages and files.