An interlocking box in five minutes

An open box, five parts, finger joints on every edge: it is the first object worth making, because it contains everything you need to know and cuts out of a small sheet.

We will make a box 150 × 110 mm, 70 high, in 4 mm plywood.

1. The five parts

In the “Material” panel set thickness 4 and clearance 0.2.

From the “New solid” panel create five rectangles and give each its sizes in the properties on the right:

• Bottom: 150 × 110
• Front and Back: 150 × 70
• Left and Right side: 110 × 70

Rename them straight away: once you have twelve parts, “Rectangle 7” tells you nothing.

2. Standing them up

The four sides need rotating by 90°. Select the front, press <kbd>R</kbd> and turn it about the X axis; the two sides need turning about Z as well. Then move them until they touch the bottom.

The shortcut that saves time is “Sit A on B” in the operations panel: select the side and the bottom, choose “on top”, and the program puts it in place for you. Then use overlap to push it in by as much as the joint needs to exist.

3. The joints

Now the part the program does for you.

• Select bottom + one side (⌘/Ctrl+click), choose “Tabs and slots” and create. Repeat for the other three sides — or select the bottom and all four sides at once: with more than two parts selected, the first one is the pivot and all the joints are created together.
• Then the vertical corners: front + left side, front + right side, and the same for the back. Again “Tabs and slots”.

The number of tabs is set in the joint panel. Few big tabs hold better; many thin tabs look finer but are more fragile. On a 150 mm side, five is plenty.

4. The file for the machine

Press “Export DXF…”. The preview shows the five parts laid out as they will be cut. Check that the joints are there, then download the DXF.

If you set your laser bed size, the parts that do not fit go on a second sheet by themselves.

Before you cut

Cut a test corner: a 40 mm piece of bottom and a 40 mm piece of side, with their joint. If they go together the way you want, cut the rest without worrying.

Try it now

Open the app — no sign-up needed — and try building this box: ten minutes the first time, three the second.