CadShift — SolidWorks Automation

Someone emailed you a .slddrw file. Or you found one on a shared drive and need to know what it contains. This post answers the practical questions: what .slddrw actually is, how it differs from SolidWorks’ other file types, how to open it without a SolidWorks license, and what data you can and can’t extract from it. What is a .slddrw File? .slddrw is the file extension for SolidWorks Drawing files. These are 2D technical drawings — the dimensioned, annotated sheets that engineers produce from 3D SolidWorks models to communicate manufacturing requirements. ...

You have 200 DWG files. Your fabricator wants DXF. Your documentation portal wants PDF. Your web team wants SVG. And nobody has an AutoCAD seat on the machine doing the conversion. This is the actual situation most engineering teams end up in. This guide covers every viable path to batch DWG conversion for all three output formats — what each tool actually supports, where each one breaks down, and how to script it so the conversion runs unattended. ...

The checkbox that lies to you Open a multi-body sheet metal part in SolidWorks and try to export DXF. File → Save As → DXF → Options. The “Export multiple flat patterns to single file” checkbox is greyed out. So is the standard “Flat Pattern” export mode. The dialog offers you geometry, hidden lines, and sketches — everything except what you actually need. This catches shops transitioning from separate-part workflows to multi-body assembly files. The multi-body approach makes sense for welded sheet metal assemblies: fewer files, shared reference sketches between bodies, no insert-part reference chains that break when you rename anything. But the DXF export dialog treats the whole assembly as one thing and can’t figure out which flat pattern to export. ...

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. ...

A user on r/SolidWorks described building a car-configurator-style model. A global variable NumSlots drove both the count of a linear sketch pattern and a sweep feature that read the slot spacing. After dragging the configuration slider, the sweep updated. The sketch pattern did not. Opening the sketch, closing it without touching anything, then rebuilding — slot count finally snapped to the new value. This is not a bug report. It is a predictable consequence of how SolidWorks schedules equation evaluation during a model rebuild. Once you understand that schedule, you stop designing models that depend on the wrong evaluation order and start structuring equations so they survive a Ctrl+B. ...

A question on r/SolidWorks last week: can you make flag note ⑤ in a drawing appear automatically in the BOM cell for line item 1? The answers suggested balloons, linked notes, and custom properties — all partially right, none complete. SolidWorks does not have a native mechanism for this. What it has is a custom property workaround that approximates the result, with specific limitations that trip people up. What flag notes are (and are not) A flag note in SolidWorks is a drawing annotation with a bordered symbol — typically a circled number like ①, ②, ③ — stored in a flag note bank. You create them via Insert → Annotations → Note, check Flag Note, and assign a border shape and symbol from the PropertyManager. Once created, a note can be added to the bank with Add to Flag Note Bank, making the symbol reusable across sheets. ...

To export a SolidWorks BOM to Excel, you have three paths — and choosing the wrong one is how you end up maintaining a 200-line macro for two months before admitting it doesn’t quite work. A post on r/SolidWorks showed exactly that: a macro that exported an assembly BOM to Excel with description, material, length, thickness, quantity, and supplier data. It mostly worked. Six comments later, nobody had a better answer than “looks fine to me.” The approach was fine — the architecture was wrong. ...

The Lofted Bend PropertyManager has a Manufacturing Method dropdown with two options: Bent and Formed. When the dropdown shows only Formed — or you select Bent and get a flat pattern with no bend lines — the root cause is almost always one of three things: sketch planes that aren’t parallel, profile geometry that has sharp corners, or connector points placed on the wrong part of the sketch entities. None of these are obvious from the error message, and the official documentation buries the parallel-plane requirement. Here’s what’s actually going on. ...

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. ...

A fabricator running a CNC tube laser — Trumpf TruLaser Tube, BLM LT-Free, Mazak FT-150 — expects the DXF cope geometry to land flush against the mating tube. When it doesn’t, someone grinds. When it really doesn’t, the joint gets welded with a visible gap, weakening the bead and failing inspection. The problem starts in SolidWorks before the export ever happens. How SolidWorks Models Weldment Tubes The SolidWorks Weldment feature builds structural members by sweeping a 2D profile sketch along a 3D path. The profile is constant — it maintains its exact shape and size throughout the entire sweep. When two members intersect, SolidWorks trims them automatically to create the cope (the curved notch that allows one tube to seat against another). ...