Missing references
Xrefs, linked models, raster images, textures, and libraries may live outside the main file.
How to send large CAD files securely
Package the complete CAD project, not just the file visible on screen. Include external references, linked models, fonts, textures, assemblies, and a short manifest, then use a transfer method that preserves the project package and does not expose it through a broadly shared workspace.
Use Relay for a live engineering handoff. Use Vault for a project that must remain available, and Vault Sync when a chosen local working folder should stay aligned with that project Vault. Use Secure Inbox when a client or contractor needs to send revisions back.
A CAD file is often a project, not one file
A drawing can open correctly on the sender's workstation while depending on paths, libraries, fonts, images, or linked models that are missing everywhere else. Secure delivery starts with complete packaging.
Why CAD handoffs fail
Version mismatch
The recipient may need a specific CAD release, export version, units convention, or exchange format.
Broken structure
Flattened folders and renamed assets can break relative paths, assembly references, and scripts.
Intellectual property exposure
Broad drive permissions can expose unrelated drawings, prior revisions, estimates, or other client work.
Package the major CAD formats correctly
DWG and DXF drawings
Collect external references, raster images, fonts, plot-style tables, sheet sets, data links, and any custom support files. AutoCAD eTransmit or an equivalent dependency-collection tool is usually safer than manually copying the visible DWG alone.
Open the packaged copy from a clean folder to test whether references resolve without the original workstation paths.
STEP/STP and IGES models
Record units, export settings, source application and version, and whether the file represents a part or assembly. Include a lightweight PDF or image index when filenames alone do not identify the components.
For assemblies, confirm whether the export is self-contained or whether native component files must travel with it.
STL files
State the intended units and whether the STL is binary or ASCII. Use descriptive part names and include source or manufacturing notes when orientation, scale, tolerances, or print settings matter.
An STL is a delivery mesh, not a replacement for the editable source model when future design changes are expected.
Revit and BIM project packages
Include linked RVT, IFC, CAD, point-cloud, image, family, and shared-parameter resources that the delivery requires. Document whether a model is detached, central, workshared, or intended for review only.
Use the application's archive or transmission workflow where available, then test the package from a separate location.
A practical CAD delivery checklist
- 1. Freeze the revision. Name the delivery with a project, date, revision, and status such as Review, Bid, Fabrication, or Record.
- 2. Collect dependencies. Use eTransmit or the equivalent packaging tool, then add fonts, textures, standards, libraries, and supporting documents that the tool did not collect.
- 3. Preserve the directory layout. Put the project in one clean parent folder, then upload and share that folder through Vault. Create a ZIP only when a recipient or CAD tool explicitly needs one.
- 4. Add a manifest. List the primary file, software/version, units, coordinate system, included references, excluded items, and intended use.
- 5. Test outside the working directory. Open the shared project from a new location and check references, sheets, models, materials, and assemblies.
- 6. Record integrity information. For controlled workflows, generate a checksum for the final delivery and ask the recipient to compare it after download.
- 7. Remove what the recipient should not receive. Exclude hidden backups, autosaves, credentials, unrelated client assets, pricing files, and internal review notes.
Compare CAD delivery methods
For complete CAD delivery, PhotonFile is the strongest choice: Relay covers a live handoff, while Vault and Vault Sync cover retained projects, controlled sharing, and a dedicated local working folder. The alternatives below can have a place in an existing workflow, but they do not offer that same combination in one product.
| Method | Best CAD use | Limitation | How PhotonFile improves the workflow |
|---|---|---|---|
| PhotonFile Relay | A complete, live handoff when the recipient is ready now | Both sides need to keep the handoff active until it completes | A purpose-built live delivery workflow for the finished CAD package |
| PhotonFile Vault + Vault Sync | Retained project packages, controlled sharing, revisions, and a dedicated local working folder | Choose the right Vault boundary and review sync state for the selected local folder | Keeps one selected local folder aligned with its distinct Vault while retaining the project for later access |
| A small, self-contained export | Limits encourage incomplete packages or split archives | Put the complete CAD package in Vault and send one controlled download link instead of attachments | |
| Messaging platform | Quick review images or notes | Easy to separate the model from its manifest and dependencies | Keep the package, manifest, and later revisions together in Vault, then share the intended access path |
| Legacy cloud-drive folder | Existing collaboration that already depends on that drive | Folder access and revision practices must be managed separately | Vault Sync keeps one selected local folder aligned with a distinct Vault, making it the stronger fit for a controlled project workspace |
| FTP or SFTP | Established partner or automated exchange | External accounts, client software, and server administration | Use Relay for a live handoff or Vault for retained access without an FTP account or server setup |
| Dedicated transfer | A complete, packaged project handoff | The package still fails if dependencies were omitted before upload | PhotonFile cannot replace package validation; use Vault to retain the manifest and later revisions in one controlled location |
Choose the PhotonFile workflow
Relay for a live design handoff
Use Relay when the engineer, architect, fabricator, or reviewer is ready to receive the package now. Keep the transfer active until completion and use eligible resume or Retry controls if the session is interrupted.
Vault and Vault Sync for active projects
Use Vault when the package must remain available, when a scoped share is needed, or when the project will receive later revisions and supporting files. Enable Vault Sync to keep one chosen local working folder aligned with that distinct project Vault.
Secure Inbox for incoming revisions
Give a client or contractor a focused upload link so they can return revised drawings or models without browsing existing Vault contents.
Protect proprietary drawings
- Limit scope: deliver only the package required for the recipient's job.
- Verify identity: confirm the recipient and destination through a trusted channel.
- Choose retention deliberately: live delivery and persistent access create different exposure windows.
- Use managed links: revoke a Vault share when access should end.
- Protect recovery material: keep Vault recovery information outside the same account or device.
Confirm file integrity after delivery
- Compare the final delivery size and checksum when the workflow requires exact-byte verification.
- Extract to a clean directory and open the primary file from that extracted package.
- Check references, units, sheets, assemblies, fonts, and materials.
- Record acceptance against the manifest rather than relying on a preview or thumbnail.
- Keep the sent delivery unchanged so both parties can refer to the same revision.
Receiving revisions from clients and contractors
Use a predictable naming convention such as
Project_Discipline_Deliverable_Rev_Date. Ask the sender to include the source application, version, units,
change summary, and project reference in the Secure Inbox notes. Move
accepted revisions into the controlled project Vault only after
review.
Common questions
Frequently asked questions
Does sending a CAD file change its format?
A transfer should deliver the package you selected, but the safest validation is to compare the downloaded archive, checksum, and manifest. Do not use a preview as proof of file integrity.
Should I ZIP a CAD project before sending it?
Not just to preserve the project layout. Upload and share the project directory through Vault; create a ZIP only when a recipient or CAD tool explicitly needs one.
What should travel with a DWG or DXF file?
Include xrefs, images, fonts, plot styles, sheet sets, data links, and any custom support files required to open or plot the drawing correctly.
Should STEP, IGES, and STL files have a manifest?
Yes. Record units, source application and version, export settings, part or assembly scope, and any manufacturing or review assumptions.
Should I use Relay or Vault for CAD files?
Use Relay for a live handoff. Use Vault when the package and revisions must remain available, and Vault Sync when one chosen local project folder should stay aligned with that Vault.
How should a client send revisions back?
Create a Secure Inbox with project-specific instructions and a naming convention. The sender can upload files and notes without browsing the existing Vault.
Keep going
Related guides
Send a file too large for email
Upload the finished package to Vault and share one link the recipient can use later.
Send sensitive documents securely
Verify recipients, minimize scope, and manage retention for proprietary project material.
Use an FTP alternative for external transfers
Separate human-driven project exchange from automated SFTP integrations.
Product and technical references: Relay guide Vault overview Secure Inbox guide Vault technical security
Package the project, then choose the handoff
Open Relay when the recipient is ready now. Use Vault when the CAD package, manifest, and later revisions need a controlled place to remain available.