SolidWorks API Gotchas: 7 Silent Failures — SelectByID2, Null Components & Rebuild Timing

Every SolidWorks API developer has spent hours debugging a macro that produces no error, no exception, and completely wrong output. The SolidWorks COM API is old enough that many of its failure modes predate modern error handling conventions — methods that silently return Nothing, boolean flags that are ignored, and side effects that modify document state without warning. This is a catalogue of the seven most common ones. Each has a pattern, a root cause, and a fix. ...

5 June 2026 · 9 min · CadShift

Batch DXF Export: SolidWorks vs Inventor — How the Sheet Metal Workflows Actually Differ

If your shop uses SolidWorks and your supplier’s shop uses Inventor, at some point you will end up comparing notes on batch DXF export. Both platforms flatten sheet metal and write DXF files. Both can be automated. The workflows look similar from a distance and differ substantially in the details that matter for production pipelines. This is a comparison of the actual automation approaches, not marketing specs. Platform capabilities are drawn from the COM API (SolidWorks) and the ObjectModel/iLogic API (Inventor). ...

4 June 2026 · 8 min · CadShift

SolidWorks API Meter Units Trap — Why SetSystemValue3 Ignores Document Units (and the Fix)

The SolidWorks API speaks one language for lengths: meters. Not millimeters. Not inches. Meters, always, regardless of what your document’s unit system displays. This sounds like something you’d learn in the first chapter of any SolidWorks API tutorial, and it is — yet it causes more silent macro failures than any other single issue. The problem is not that developers don’t know about it. The problem is that it bites you in a second way you didn’t expect, in a context you were already confident about. ...

3 June 2026 · 7 min · CadShift

When to Upgrade from a SolidWorks Macro to a Full Add-in

A SolidWorks macro gets you 80 percent of the way there. It can open files, traverse assemblies, read custom properties, save DXF, and close — all without writing a line of C#. The VBA IDE ships inside SolidWorks, the API reference is documented, and a working batch export macro can be running in an afternoon. Then the macro breaks in a way that a one-line fix will not solve. Or someone needs it on fifteen workstations, or the team wants a toolbar button, or the workflow needs to respond to file saves without being manually invoked. That is when engineers discover that “just adding a button” requires a complete architectural shift. Macros and add-ins are not on the same continuum — they differ at the design level, and the capabilities that matter most to production workflows sit entirely on the add-in side of that line. ...

1 June 2026 · 8 min · CadShift

Slicing a SolidWorks Part into Per-Layer DXFs for Additive and Layer-by-Layer Machines

Layer-by-layer manufacturing covers more territory than most engineers realize. Laminated object manufacturing (LOM), sliced tooling blocks for composite layup, sectioned mold plates for waterjet stacking, large-format CNC where layers are cut and stacked — all of these need DXFs at specific Z heights. SolidWorks doesn’t have a “slice and export” button. But there are three workable approaches, and one of them scales with an API. The problem in concrete terms A customer operates a layer-by-layer cutting machine: it takes DXF profiles at fixed Z-height increments (say, 3mm steps), cuts each layer from sheet stock, and stacks them to build up a 3D form. Your job is to deliver fifty DXF files, each representing the cross-section of the part at a different height. ...

31 May 2026 · 8 min · CadShift

Why SolidWorks DXF Export Settings Don't Persist — And the API Fix That Makes Them Stick

You spend ten minutes configuring the DXF export dialog — turning on bend lines, setting the layer map, choosing which sketch entities to include. You close SolidWorks. You open it the next morning and every checkbox is back to the default. Again. This is one of the most reliably frustrating behaviors in SolidWorks, and it has a specific technical reason that most documentation skips over. More importantly, there are three concrete fixes — ranging from a template trick to a four-line API call — that eliminate the problem entirely. ...

30 May 2026 · 6 min · CadShift

Fusion 360 Integrated CAD/CAM vs SolidWorks CAM Add-ons — Which Is Actually More Seamless?

The marketing claim that Fusion 360 has “seamless” integrated CAD/CAM is technically accurate and practically misleading — depending entirely on where your design data comes from. This comparison breaks down how each approach works, where the integration claim holds up, and where it falls apart. For background on the broader platform comparison, see SolidWorks vs Fusion 360 vs Inventor 2026. How Fusion 360 CAM Actually Works Fusion 360’s CAM environment (the Manufacture workspace) shares the same file as the design. When you switch from the Design workspace to Manufacture, you are looking at the same geometry, in the same session, with no export or import step. The feature timeline is accessible. Selections persist. When you modify the model and return to Manufacture, setups reference the updated geometry. ...

29 May 2026 · 8 min · CadShift

Switching from SolidWorks to Fusion 360 — What You Actually Lose (and What You Gain)

The question comes up regularly on engineering forums: what do I actually lose if I move from SolidWorks to Fusion 360? The marketing pages from Autodesk give you the answer they want you to hear. This post gives you the engineering answer — what specific workflows break, what you have to rebuild from scratch, and where Fusion genuinely earns its place. For full platform positioning, the SolidWorks vs Fusion 360 vs Inventor comparison covers pricing, kernel differences, and which platform fits which team size. This post focuses narrowly on the migration decision: you have years of SolidWorks work, and you’re evaluating whether to move. ...

28 May 2026 · 9 min · CadShift

STEP Files vs Native SolidWorks: Why Fabricators Rebuild Instead of Convert

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. ...

26 May 2026 · 10 min · CadShift

AI CAD Tools vs CAD Workflow Automation — Why They Solve Different Problems

SolidWorks 2026 ships with AutoGenerate Drawing — an AI feature that takes a 3D model and produces a dimensioned 2D drawing with views, annotations, and BOM in the background while you keep working. LinkedIn posts about AI-generated macros and SolidWorks MCP servers are getting traction. The question is a reasonable one: if AI can generate drawings and answer questions about your model in natural language, what’s left for automation tools to do? ...

25 May 2026 · 7 min · CadShift