The van bed I keep redesigning as three boxes

I keep returning to the same layout: a van bed that is really three storage boxes under a sleeping platform. Two drawer units on the sides, one open chest down the middle, and a bed board that spans the top. It is the most useful thing I have drawn for camper builds, and it is the project clients ask about most when they want to hire CAD designer for van conversion files.

The version in my portfolio is 120 cm wide and 190 cm long closed. Each module is 56 cm high, which gives enough depth for clothes, tools, or a fridge slide underneath. But the real point is not the dimensions. The point is that three modules make the bed adaptable. If the client buys a different van later, we keep one or two boxes and redesign only the missing piece. A single fixed bed frame does not forgive that kind of change.

Why modules win

A full-size van bed frame is a big sheet of plywood with dozens of joints. If the wheel-arch spacing changes by 30 mm, you are redrawing half the panels. With three modules, the side drawer units sit against the wheel arches independently. The middle chest only cares about the floor between them. The bed board adjusts in length. That is the whole advantage: local changes stay local.

The middle chest also carries the load path. The bed board rests on the side units and the middle box, so the span is short. I have had clients stand on the platform to test it. No flex. That matters because people always underestimate how heavy a mattress plus two humans is.

The design system

I model the modules in one parametric file. Sheet thickness is a variable, not 18 mm hard-coded. In the real world, a sheet labeled 18 mm can measure anywhere from 17.1 mm to 18.7 mm under EN 315, and premium birch can still vary by a few tenths. I measure the actual batch and update the parameter once. Every dado, every shelf pin hole, every bolt hole shifts with it.

The joint I use most is a dado with dogbone corners. The CNC router cannot cut a sharp internal corner, so the dogbone lets a rectangular panel slide into a slot without fighting the bit radius. Slot width is actual thickness plus a small clearance. I usually start around 0.1 mm total clearance for a snug glued fit in birch plywood. Test cut, adjust, then run the sheet.

Bolt holes are 6.6 mm diameter for M6 hardware, which is the normal clearance fit. Any tighter and the bolt binds when the plywood swells. Any looser and the joint feels sloppy. Shelf pin holes are 5 mm for the European system, spaced on 32 mm centers. I keep them 37 mm from the front edge so standard adjustable brackets line up.

Cutting and assembly

I nest the parts on a 2500 × 1250 mm sheet. That is the standard EU birch plywood size, and it fits most affordable CNC routers. A single bed set typically uses two sheets for the boxes plus one smaller sheet or offcut for the bed board and braces. I add labels and orientation marks directly in the DXF so the workshop does not have to guess which tab faces forward.

Assembly is flat-pack logic. No special tools beyond a rubber mallet, wood glue, and a few clamps. The modules slide in separately, get leveled on the van floor, and bolt together through pre-drilled holes. A single person can install it in an afternoon. That matters when the client is working on a driveway in the rain.

What I still change

The fridge slide is the part I argue about most. Some clients want it under the bed board behind the middle chest. Others want it in the middle chest itself. Each choice changes the chest depth, the ventilation gap, and the front panel cutout. Because the model is parametric, I can move the divider and regenerate the panels in minutes instead of hours.

The bed board is the second moving target. Some people want it split in half for access. Others want a continuous panel. I usually start split, because it is lighter and lets you reach the middle chest from above. If the client wants a solid top, I merge the halves and add a stiffener rib.

Why this is the project I show people

It is not the most impressive thing in the portfolio. It is just a bed. But it is a bed that proves a way of working: design with the workshop in mind, cut once, assemble without a manual, and leave room for the client to change their mind. That is what custom van bed storage design files for CNC router work should look like. Not a perfect render. A box that fits.

[IMAGE: A dark studio exploded isometric render of three modular van bed base units. Left and right drawer units with sliding drawers partially open, central open chest, and a split bed board floating above. Amber accent edges on handles and joints. Dogbone corner cuts visible. CAD dimension lines and 2500×1250 sheet outline ghosted in background. Graph paper texture at low opacity. No text. 3:2 aspect ratio.]