Choosing the wall thickness for printed boxes and bins
Get the walls right and a printed box is quick, strong and clean. Get them wrong and the slicer fills the gap with thin zig-zags that look rough and print slowly.
Think in lines, not millimetres
A 0.4 mm nozzle lays lines about 0.42 to 0.45 mm wide. Walls that are a whole number of lines fill cleanly:
| Wall | Lines | Use it for |
|---|---|---|
| 0.8 mm | 2 | Dividers and light trays |
| 1.6 mm | 4 | Everyday bins and boxes |
| 2.0 mm | 4 to 5 | Sturdy trays, things that get knocked about |
| 2.4 mm | 5 to 6 | Gift boxes and parts that need to feel solid |
The floor is counted in layers: 1.6 mm is eight 0.2 mm layers, 2 mm is ten.
Outside or inside?
Decide which size matters. A box that has to fit a drawer is an outside size. A box that has to hold something is an inside size, so add the walls:
- outside length = inside length + 2 × wall
- outside height = inside depth + floor
Eight AA batteries standing in two rows of four need about 60 × 31 mm inside, 30 mm deep. With 1.6 mm walls and floor, that's a 63.5 × 34.5 × 32 mm box.
Leave some room
Add 1 to 2 mm to the inside for things to slide in and out. Printed sizes can also come out a few tenths of a millimetre small inside, depending on your printer and filament.
Box Maker takes outside sizes and shows the inside size as you type. Its examples include the AA box, a sticky note holder and a drawer tray.