STEP AP203 vs AP214 vs AP242 — Which Version to Send Your Supplier (and the AP242 PMI Trap)

When SolidWorks shows you the Save As dialog, three STEP variants appear in the dropdown: AP203, AP214, and AP242. Most engineers pick one, never change it, and assume the output is correct. Sometimes it is. Sometimes half the data you expected to transfer isn’t in the file at all, and you find out when the supplier calls. This post explains what each version actually carries, what SolidWorks and Inventor write for each, and which one to choose based on what your recipient needs on the other end. ...

22 June 2026 · 8 min · CadShift

Estimating Flat Blank Area for Stamped and Formed Sheet Metal in SolidWorks

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. ...

20 June 2026 · 9 min · CadShift

SolidWorks vs Fusion 360 for Sheet Metal — DXF Layer Control and Flat Pattern Quality

The question of SolidWorks versus Fusion 360 for sheet metal comes up constantly in manufacturing communities. Most comparisons focus on modelling speed, K-factor accuracy, or bend table flexibility. What they skip is the output side: what the DXF file actually looks like when it hits the laser cutting operator’s desk, and whether the nesting software can consume it without manual cleanup. This matters because the DXF is the handoff document. Everything downstream — nesting, laser cutting, press brake setup — depends on the geometry, layers, and metadata in that file. A flat pattern that looks identical in both tools can produce dramatically different DXF outputs. ...

19 June 2026 · 8 min · CadShift

SolidWorks VBA API Events: Why Your Event Handlers Die When the Macro Stops

You set up a WithEvents handler in a SolidWorks VBA macro. The macro runs, SolidWorks does something (opens a document, rebuilds, saves), and your handler fires correctly. Then you close the macro editor and try to use SolidWorks normally — the handler no longer fires. The macro is gone, and so is your event subscription. This confuses VBA developers who are used to Office automation, where event handlers in a document’s VBA project persist as long as the document is open. SolidWorks works differently. Here’s why, and how to keep handlers alive when you need them. ...

15 June 2026 · 7 min · CadShift

Managing Large CAD Assemblies — File Size Limits, Performance Thresholds, and Strategies for SolidWorks, Inventor, and Fusion 360

Large assemblies break the assumption that CAD tools “just work.” At some threshold — different for each platform — the software stops being interactive and starts being a waiting exercise. The difference between a team that manages large assemblies well and one that doesn’t is almost entirely about the tools and workflows they choose to use, not about hardware. This guide covers the performance toolkit for SolidWorks, Inventor, and Fusion 360, with specific attention to where each platform’s approach breaks down and what you can do about it before the assembly grows too large to manage. ...

12 June 2026 · 12 min · CadShift

SolidWorks DXF Has Disconnected Curves — Spline Constraints and Chord Tolerance Explained

You export a flat pattern from SolidWorks, send the DXF to the laser cutter, and get a phone call: “There are open loops in your file. The machine can’t run it.” You open the DXF back in SolidWorks, zoom in, and the outline looks fine. Zoom in further. There’s a 0.003 mm gap between two arc endpoints at a spline junction. This problem has two distinct root causes that require different fixes. Conflating them wastes time. Here is what is actually happening in each case. ...

9 June 2026 · 8 min · CadShift

The Save Bodies Command: SolidWorks' Hidden Batch Part Extractor

A Reddit post asking about converting solid bodies to individual part files got 77 upvotes. The top comment pointed to Insert → Features → Save Bodies — and multiple replies said they’d never heard of it despite years of SolidWorks use. CSWP holders included. This is not a niche feature. It’s the correct way to extract individual part files from a multi-body part, and it does things that Insert into New Part and manual workflows cannot match. ...

8 June 2026 · 7 min · CadShift

SolidWorks 2025 Freezing Your PC? Fix the sldShellExtServer DCOM Error

Your machine doesn’t crash. Nothing shows an error dialog. Windows just stalls — File Explorer hangs for 5 to 30 seconds, the taskbar goes unresponsive, and then everything unfreezes as if nothing happened. This happens repeatedly, and it always seems to coincide with working near SolidWorks files. The culprit is sldShellExtServer.exe, the SolidWorks shell extension server, and it’s been causing more friction in SolidWorks 2025 than previous versions. Here’s how to confirm it’s the source and how to fix it without a support ticket. ...

7 June 2026 · 8 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