# Pack a CAD Assembly ZIP: Choose the Root and Keep Paths

Package an assembly with its referenced parts, keep relative folders, and choose the root model so missing components are visible instead of silent.

This guide covers general CAD workflows. CADProps supports STEP, IGES, SolidWorks parts and ZIP assemblies, STL, OBJ, 3MF and static GLB/GLTF. Validated conversions are downloadable. Partial assemblies carry warnings; properties cover loaded geometry only.

A CAD assembly is rarely one file. SolidWorks, CATIA, Inventor and similar systems store the assembly and its parts separately, then point from the assembly to those parts with relative paths. A ZIP is useful only when it preserves that structure.

Open the package in the [ZIP viewer](https://www.cadprops.com/tools/zip-viewer/index.md). If several models are present, choose the assembly root rather than a single part that happens to sit at the top of the archive.

## Put the assembly and its parts in one archive

Include the root assembly and every component it references. Nested assemblies belong in the same ZIP, still in their own folders. Renaming the archive does not find parts that were left out.

Keep the relative folders the CAD system wrote. Moving every file into one flat directory breaks references that use a path such as `parts/bracket.sldprt`. SolidWorks documents this kind of package in [Pack and Go](https://help.solidworks.com/2017/english/SolidWorks/Sldworks/c_pack_and_go.htm); other systems have their own pack command. Use that command when you have it, then zip the result without rearranging it.

## What this viewer will not open

The package is limited to 50 entries and 100 MiB after expansion. Encrypted archives, nested ZIPs, symlinks, paths that climb out of the archive, and links to remote files are rejected. A glTF scene can be packaged with its local buffers and images; remote texture URLs are not fetched.

## Choose the root when the ZIP contains more than one model

An archive of a machine often contains the top assembly, subassemblies and parts. Opening an arbitrary part shows that part, not the machine. Select the root assembly the sender named.

Missing components produce a warning when some geometry still loads. Dimensions, volume and mass then describe the loaded geometry only. They are not the complete assembly. The same rule is covered for [SolidWorks assemblies](https://www.cadprops.com/guides/sldasm-missing-parts/index.md), [CATIA products](https://www.cadprops.com/guides/catproduct-missing-parts/index.md) and [Inventor assemblies](https://www.cadprops.com/guides/iam-missing-parts/index.md).

## Check the package before you convert it

1. The expected root model is selected.
2. The warning list is empty, or every missing name is understood.
3. One known dimension matches the drawing or the sender's note.
4. Component placement looks like the intended assembly, not a pile of parts at the origin.

After that, convert only if the next system needs a different format. Use the [conversion checklist](https://www.cadprops.com/guides/cad-conversion-checklist/index.md) on the output. A successful conversion of an incomplete ZIP is still an incomplete model.

## Related reading

- [CAD File Conversion Checklist: Units, Solids & Accuracy](https://www.cadprops.com/guides/cad-conversion-checklist/index.md)
- [CATProduct Missing Parts? Fix CATIA Assembly References](https://www.cadprops.com/guides/catproduct-missing-parts/index.md)
- [IAM Missing Parts? Fix Autodesk Inventor Assembly References](https://www.cadprops.com/guides/iam-missing-parts/index.md)
- [Open a Rhino 3DM File Without Rhino](https://www.cadprops.com/guides/open-3dm-without-rhino/index.md)
- [Open CAD Files on Mac: STEP Viewers and Format Options](https://www.cadprops.com/guides/open-cad-files-on-mac/index.md)
- [How to Open a CATPart File Without CATIA](https://www.cadprops.com/guides/open-catpart-without-catia/index.md)
- [SLDASM Missing Parts? Fix SolidWorks Assembly References](https://www.cadprops.com/guides/sldasm-missing-parts/index.md)

Original article: https://www.cadprops.com/guides/zip-packaged-cad-models/

HTML page: https://www.cadprops.com/guides/zip-packaged-cad-models/