Have you ever sent a sheet metal flat pattern to the factory...

And they accidentally laser-cut your part into three separate pieces?

You probably forgot to clean up your DXF export. Here is the ultimate Standard Operating Procedure (SOP) for exporting sheet metal. 👇

When you flatten a 3D sheet metal part in your CAD software, the screen shows you the outer shape of the unbent metal.

But it also generates internal lines to show exactly where the bend radii are located.

Here is the problem: A CNC laser cutter is essentially just a very powerful, very dumb robot.

It does not know the difference between an "outer profile cut" and an "internal bend line." It just sees a line, and it fires the laser.

If you export your raw flat pattern with all those extra lines turned on, the laser will literally slice your part into pieces right down the bend radius.

To guarantee a perfect cut every time, follow these 3 rules for your DXF export SOP:

𝟭. 𝗛𝗶𝗱𝗲 𝘁𝗵𝗲 𝗥𝗮𝗱𝗶𝘂𝘀 𝗟𝗶𝗻𝗲𝘀

Before you click export, you must turn off or hide all bend lines, radius lines, and bounding boxes. The final DXF should look like a hollow silhouette. Nothing should be inside the outer perimeter unless it is an actual hole you want cut.

𝟮. 𝗗𝗲𝗹𝗲𝘁𝗲 𝘁𝗵𝗲 𝗧𝗶𝘁𝗹𝗲 𝗕𝗹𝗼𝗰𝗸

Never export your DXF from a 2D drawing sheet that has a title block, borders, or text notes. The laser software will try to cut out every single letter of your name and the date. Export the geometry at a strict 1:1 scale with a completely blank background.

𝟯. 𝗕𝗲𝘄𝗮𝗿𝗲 𝗼𝗳 𝗦𝗽𝗹𝗶𝗻𝗲𝘀

If your design has complex, sweeping curves (splines), old CNC machines will panic and crash. Always ensure your export settings are configured to convert all splines into simple lines and arcs (polylines).

💡 𝗣𝗥𝗢 𝗧𝗜𝗣: If the factory needs to know where the bend lines are, put them on a separate, clearly labeled DXF layer (usually called "Etch" or "Marking"). The operator can then program the laser to lightly engrave those lines instead of cutting through the metal!

Have you ever had a factory cut a part completely wrong because of a messy DXF file? Let me know below! 👇