Fabrication

A fabricator opens your STEP file. They run Insert Bends. SolidWorks creates a flat pattern. The dimensions are wrong. Not slightly wrong — off by several millimetres on every bend. Enough to cause rework. Enough to get a call from the shop floor. The reason is that STEP files don’t carry k-factor data. They never did. Understanding why, and what to do about it, is the difference between a clean handoff and a rebuild. ...

Bent sheet metal has a flat pattern. SolidWorks can unfold every edge flange, miter flange, and sketched bend into a precise blank geometry, and the SW-Flat Pattern Area cut-list property captures the result automatically. Formed and stamped parts are a different story. A drawn cup, an embossed panel, a hydroformed bracket, a stamped louver grid — SolidWorks models these as solid bodies or as sheet metal with Form features, but there is no flat pattern feature, no unfolding algorithm, and no built-in blank area property. When a fabricator or a quoting tool asks for the blank size, you have to find it yourself. ...

A customer sends you a .stp file. It’s a sheet metal part — clearly visible bends, uniform thickness, nothing exotic. You import it into SolidWorks, run Convert to Sheet Metal, and SolidWorks does… something. A flat pattern appears. You run the DXF export and send it to the laser table. Then the first batch comes back wrong: the developed length doesn’t match the customer’s tolerance, some bends are reversed, and the corner relief geometry is completely off. ...

A fabricator needs to quote material. You hand them a bracket modelled as a solid body — not a sheet metal part, no flat pattern feature, just an extrusion with a uniform thickness. They want the raw stock area: how many square millimetres of plate does this part consume before cutting. SolidWorks Mass Properties gives you volume, surface area, and inertia. But the total surface area of a solid body includes every face — both flat faces, four edges, any chamfers or holes. That number is meaningless for material estimation. What you need is the area of one face, or equivalently, the part’s volume divided by its thickness. ...

Waterjet cutting is not laser cutting. A programmer at a waterjet shop evaluates your DXF differently than a laser operator does, and the geometry problems that a laser CAM system tolerates will stop a waterjet program cold. This post covers what you need to know before the file leaves your desk: kerf width, taper, lead-in placement, pierce rules, minimum features, and the geometry requirements that every waterjet CAM system actually checks. ...

Engineers tend to think about DXF quality in terms of geometry accuracy. Does the flat pattern dimension match the folded part? Are the holes in the right positions? Is the file exported at the correct scale? These things matter. But they’re the minimum requirement. Fabricators — particularly laser cutting shops and press brake operators — need significantly more from a DXF file to actually process a part without back-and-forth. The geometry tells them what to cut. Everything else tells them how to do the job. ...