support-fins/plugins/solidworks

Support Fins — SolidWorks add-in

A SolidWorks add-in that puts printfins.com supports in the part instead of the slicer: breakaway walls under the overhangs, gripped by one-layer tines, and a bed pad where the part barely touches the plate, each inserted as its own solid body.

The geometry comes from the website's engine itself (web/*.js, unmodified, bundled through plugins/shared/ like every other plugin), run by Microsoft Edge WebView2, so at the site's speed (V8 with its JIT), in its own process: SolidWorks never waits on it. A fix on the site reaches SolidWorks with the next build. Started from @Haititei's add-in in #183 (ribbon command, reading the part's tessellation, the Y-up frame).

Status: experimental, not yet run in SolidWorks. It builds, its page is tested against the engine and in a browser, and nothing it ships is SolidWorks-version specific, but the SolidWorks side (registration, ribbon, reading the part, importing the bodies) has not been run on a SolidWorks install. Reports welcome.

Install

Needs SolidWorks on 64-bit Windows, .NET Framework 4.8 (standard on Windows 10/11) and the WebView2 Runtime (part of Windows 11 and current Windows 10; the add-in says so if it's missing).

1. Download support-fins-solidworks.zip from the plugins-latest release and unzip it somewhere it can stay (SolidWorks loads the add-in from that folder).
2. Right-click SupportFins\install.bat › Run as administrator (COM registration writes to HKEY_LOCAL_MACHINE).
3. Restart SolidWorks. Support Fins is under Tools › Add-Ins (loaded at startup) and has its own Support Fins tab in parts.

uninstall.bat (as administrator) removes it; fins already inserted stay in your parts.

Use

1. Open a part, pose it the way it will print, and click Support Fins. A small window opens beside SolidWorks and reads the part: every visible solid body.
2. Print bed (Stands on): Top Plane (Y up), SolidWorks' default, for a part modelled standing on the Top Plane; Front Plane (Z up) for one modelled Z up; or Selected face: select the flat face the part stands on, then press Read part. Whichever side of the face the part is on is up.
3. Settings: the website's (overhang angle, tines, tine grip, layer height, support gap, bed pad, sway braces, cutouts, wide-face coverage), built from the same options.json every plugin uses. Layer height must match your slicer: the tines are one layer tall. Settings are remembered.
4. The readout gives the walls and tines, and what to check: overhangs too shallow for a fin this way up, pieces that start in mid-air. Click Insert.

Each piece goes in as its own imported solid body: Support Fins wall 1, Support Fins sway brace 1, Support Fins bed pad. Delete any you don't want. The next run skips (and counts) bodies named Support Fins…, so fins never get fins. Export the part and the fin bodies together (STL/3MF); the tines overlap the part by 0.01 mm and the slicer merges them.

Edited the part? Press Read part before Insert: the fins are for the part as it was last read.

How it runs

SupportFins/
  Addin.cs              ISwAddin: COM registration, the ribbon command, the window
  FinsWindow.cs         the window: WebView2 showing page/, answering its messages
  PartReader.cs         visible solid bodies -> triangles (part frame, mm); the selected face
  FinImporter.cs        one STL per piece -> InsertImportedFeature, named; import settings
                        (solid body, mm, no diagnostics) set for the import and put back
  page/index.html, dialog.js, style.css   the dialog: settings, readout, Insert
  page/host.js          bed -> pose -> engine -> back to the part frame -> STL per piece
  page/fins_engine.js   the engine bundle (built, not committed)
  icons/                ribbon icons
tests/host.test.js      host.js against the real engine (deno test)

Page and add-in talk in JSON messages (spelled out at the top of page/dialog.js): the add-in sends the part as base64 float64 triangles, the page answers Insert with one base64 STL per piece. The page is served from the add-in folder under a virtual host, so nothing loads from the network.

SolidWorks' interop assemblies are a compile-time NuGet reference with their types embedded in the DLL: no Dassault DLL ships, and the add-in isn't tied to one SolidWorks release's interop. (The NuGet packages are third-party repackagings of the interop; they are used only to compile.)

Develop

python3 plugins/solidworks/build.py          # engine bundle into SupportFins/page/
python3 plugins/solidworks/build.py --zip    # + dotnet build -> build/support-fins-solidworks.zip
deno test --allow-read plugins/solidworks/tests/

--dll/--zip need the .NET SDK (8 or later; any OS, the add-in targets .NET Framework 4.8 through reference assemblies). To debug the page, press F12 in the window for DevTools, or open page/index.html in a browser (without SolidWorks it says so).

Bump <Version> in the .csproj with each add-in change: the dialog shows it, so you can tell which build SolidWorks loaded.

Hand test (SolidWorks)

• install.bat as administrator succeeds; SolidWorks lists Support Fins under Tools › Add-Ins
• first: Insert one piece (a part with one wall) goes in as a solid body; if every piece fails, InsertImportedFeature doesn't take STLs on this release
• the Support Fins tab shows in a part, with its icon; the button is greyed out in an assembly
• the window opens beside SolidWorks; readout gives walls and tines for a part with overhangs
• Top Plane / Front Plane / Selected face each put the fins under the part as posed
• Insert adds one Support Fins… solid body per piece, in the right place and size (mm and inch parts)
• a wall with tines is one body (the tines unioned into it), not one body per tine
• close the window and click Support Fins again: it reopens
• a curved part at the document's coarse and fine image quality: fins land under the overhangs either way (the mesh is SolidWorks' display tessellation)
• a second run says the earlier bodies were left alone and doesn't fin them
• your own STL import settings are as they were afterwards
• exported with the part, it slices like the website's download
• uninstall.bat removes it