Exporting Cut Files That Actually Cut
A printed cut sheet and a machine-ready cut file solve two different problems. One is for a person with a tape measure and a saw. The other is for a router or laser that reads geometry directly. Confusing the two is the most common reason a shop's first CNC job comes back wrong.
What a person needs vs what a machine needs
A person reads a cut sheet: a list of panels with dimensions, a diagram of how they fit, and notes on port routing and joinery. They interpret it, mark the MDF, and cut with their own allowance for the blade.
A machine reads a path. It does not interpret. A DXF export has to describe every cut as exact vector geometry in real-world units, on the right layers, with closed shapes where the machine expects closed shapes. Anything ambiguous either fails to load or cuts wrong.
Units and scale are the first thing to check
The single most common CNC failure is a file that loads at the wrong scale. DXF has no universal unit; the file declares one, the machine software assumes one, and if they disagree your 400 mm panel can come in at 400 inches (a millimetre file read as inches) - wildly oversized and instantly obvious, or worse, subtly off if the two units are closer.
RokketBox exports DXF in millimetres. Before you cut, load the file and measure one known dimension against what the design says. A 10 second check saves a sheet of MDF.
Layers separate cuts from marks
A production DXF is not one undifferentiated pile of lines. Panel outlines, driver cutouts, port openings, and score/fold lines belong on separate layers so the machine operator can assign each to the right tool and cut order: a through-cut for the outline, a pocket or through-cut for the cutouts, and a shallow score for a kerf-bend fold.
If everything is on one layer, the operator has to re-sort it by hand, which defeats the point of exporting a machine file at all.
Closed paths cut, open paths do not
A circle cutout has to be a closed loop. If the export leaves a tiny gap where the path should meet, the machine either refuses the toolpath or cuts a slot instead of a hole. This is why a DXF that looks fine on screen can still fail on the machine: the eye does not see a 0.01 mm gap, but the CAM software does.
Kerf and tool diameter are not in the file
A cut file describes the design geometry, not the cut allowance. The router bit has a width (the kerf), and the machine offsets its path by half that width so the finished part matches the drawing. That offset is set in the CAM software, not the DXF.
The practical consequence: do not pre-shrink your panels to "account for the blade." Export the true dimensions and let the machine's kerf compensation do its job. If you compensate twice, every joint ends up loose.
The proof step
Before committing a full sheet, run the file on a scrap offcut, or at minimum do a dry run with the tool raised. Confirm the outline size, that the cutouts land where they should, and that the fold scores are shallow rather than through-cuts. A machine does exactly what the file says, which is a strength once the file is right and a liability until it is.
Where RokketBox fits
RokketBox generates both outputs from the same box: a printable cut sheet for hand building, and a DXF for the machine. The DXF carries the panel outlines, driver and port cutouts, and kerf-bend fold lines as real millimetre geometry, so the file that leaves the browser is the file the machine cuts.