> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmon.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CAD & Drawing Automation

> Apply the same operation — defeaturing, drawing creation, export, renaming — across many files at once.

## Overview

Some CAD work isn't hard, it's just repetitive: the same drawing template applied to two hundred parts, the same defeaturing rule run across a supplier library, the same title-block field updated on every sheet in a project. Doing it by hand doesn't take skill, it takes hours.

Nexus runs a single instruction across an entire folder, assembly, or file list — applying the same operation consistently everywhere, and reporting back what changed on each file. Anything you'd otherwise do with a macro, Nexus can usually do from a plain-language instruction, and it can save the sequence as a reusable skill for the next time the same job comes up.

## What Nexus can help with

* **Bulk drawing creation** — Generate a standard drawing for every part in a folder or assembly, using the same template and view scheme.
* **Batch defeaturing** — Apply a simplification rule (suppress fasteners, remove small fillets, strip cosmetic features) across every file in a set.
* **Batch export** — Convert a folder of parts to STEP, IGES, PDF, or another format in one pass, with consistent naming.
* **Bulk metadata and title-block updates** — Update a custom property, revision, or title-block field across every drawing in a project.
* **Repeatable skills** — Save a sequence you run often as a named skill, then re-run it on a new file or folder with one prompt.

## Example prompts

<AccordionGroup>
  <Accordion icon="file-lines" title="Bulk drawing creation">
    ```text theme={null}
    For every part in C:/Projects/Bracket_Family/, generate a standard drawing using the template at C:/Templates/ISO_A3.drwdot: Front + Right view, third-angle, fully dimensioned from the model's DimXpert data. Save each drawing next to its part with the same file name and a .SLDDRW extension. Report which parts failed and why.
    ```
  </Accordion>

  <Accordion icon="broom" title="Batch defeaturing across a supplier library">
    ```text theme={null}
    Across every part in C:/Projects/Supplier_Parts/, suppress all fasteners (screws, nuts, washers), remove fillets below 1mm radius, and strip embossed logos and cosmetic text. Save each result as a new file with a "_simplified" suffix, leaving the originals untouched.
    ```
  </Accordion>

  <Accordion icon="file-export" title="Batch export">
    ```text theme={null}
    Export every part in C:/Projects/Release_Candidates/ to STEP AP242 and PDF. Use the same base file name for both outputs and place them in a new /export subfolder. List any parts that failed to export cleanly.
    ```
  </Accordion>

  <Accordion icon="table" title="Bulk title-block or metadata update">
    ```text theme={null}
    Across every drawing in C:/Projects/Pump_Assembly/, update the title-block revision to "C" and add the note "Updated per ECN-4471" to the revision table. Do not touch drawings already at revision C. Report the list of files changed.
    ```
  </Accordion>

  <Accordion icon="repeat" title="Save a repeatable skill">
    ```text theme={null}
    Save the steps we just ran — suppress fasteners, remove sub-1mm fillets, export to STEP — as a skill called "prep-supplier-part". Next time I attach a new supplier part, I'll just say "run prep-supplier-part on this".
    ```
  </Accordion>
</AccordionGroup>

## A typical batch workflow

<Steps>
  <Step title="Scope the batch">
    Tell Nexus exactly which files are in scope — a folder, a file list, or every component in an assembly — so nothing outside the intended set gets touched.

    ```text theme={null}
    List every SLDPRT file in C:/Projects/Bracket_Family/ and its subfolders. Confirm the count before we proceed.
    ```
  </Step>

  <Step title="Dry-run on one file">
    Validate the rule on a single representative file before applying it everywhere.

    ```text theme={null}
    Run the defeaturing rule (suppress fasteners, remove sub-1mm fillets) on just C:/Projects/Bracket_Family/bracket_01.SLDPRT and show me the result before continuing.
    ```
  </Step>

  <Step title="Run across the batch">
    Apply the validated rule to the full set.

    ```text theme={null}
    Apply the same rule to the rest of the files in that folder. Save each as a new file with a "_simplified" suffix and leave the originals untouched.
    ```
  </Step>

  <Step title="Report results">
    Ask for a structured summary rather than assuming every file succeeded silently.

    ```text theme={null}
    Give me a table: file name, whether it succeeded, and how many features were removed. Flag any file that failed or needed manual review.
    ```
  </Step>
</Steps>

## Feature tree optimization

A feature tree that only makes sense to the person who built it is a liability the moment anyone else — a teammate, a reviewer, a configuration tool — has to touch the part. Renaming and reorganizing it by hand, feature by feature, is exactly the kind of repetitive work Nexus can take on directly.

### What Nexus can help with

* **Descriptive renaming** — Replace generic names ("Boss-Extrude12", "Cut-Extrude3") with names that describe what each feature does.
* **Folder organization** — Group related features into folders by function or build stage, so the tree reads top to bottom as a sequence of intentional steps.
* **Redundancy cleanup** — Flag features that duplicate or could be consolidated with another (two separate fillet features that could be one, a sketch with unused geometry).
* **Automation prep** — Name and tag the specific features and dimensions that drive variation, so a configuration tool like DriveWorks — or a design table — can reference them reliably.

### Example prompts

<AccordionGroup>
  <Accordion icon="tag" title="Rename and organize a feature tree">
    ```text theme={null}
    Name every feature in the open part based on what it does, not its default name. Then group related features into folders: mounting features, venting features, and structural ribs.
    ```
  </Accordion>

  <Accordion icon="sitemap" title="Prep a model for DriveWorks automation">
    ```text theme={null}
    This part will drive a DriveWorks configuration. Rename and tag every feature and dimension that changes across the family — hole pattern, boss diameter, overall length — so the logic can reference them by name instead of by position in the tree.
    ```
  </Accordion>
</AccordionGroup>

## Generative design assistance

Sometimes the question isn't "automate this known step" but "show me options I haven't thought of." Nexus can generate alternative geometry for a part under a stated load case and target — a starting point to explore, not a finished design.

<Note>Treat generative output as a concept to evaluate, not a part to release. Validate the strongest candidate with a full analysis (see [Simulation preprocessing](/cae/preprocessing)) and a [DFMA pass](/cad/dfma-design-review) before it goes anywhere near production.</Note>

### What Nexus can help with

* **Concept generation** — Propose alternative geometry (rib layouts, lattice regions, load paths) for a part given boundary conditions and an objective, such as minimum mass or maximum stiffness.
* **Variant comparison** — Generate several distinct concepts side by side so you can compare trade-offs before committing to one direction.
* **Constraint-aware exploration** — Respect stated keep-out zones, mounting interfaces, and envelope limits while exploring the rest of the geometry freely.

### Example prompts

<AccordionGroup>
  <Accordion icon="shapes" title="Explore alternative geometry under a load case">
    ```text theme={null}
    Generate three alternative rib layouts for this intake manifold under the stated pressure load (350 kPa internal), optimizing for minimum mass. Keep the mounting bosses and port locations fixed. I'll validate the best candidate with a full FEA run before committing to one.
    ```
  </Accordion>

  <Accordion icon="cubes" title="Lightweight a bracket within a fixed envelope">
    ```text theme={null}
    Within the existing 120x80x40mm envelope, explore lattice or rib-based alternatives to the solid bracket that reduce mass by at least 30% while keeping the two mounting faces and four bolt holes exactly as they are. Show me two to three distinct concepts.
    ```
  </Accordion>
</AccordionGroup>

## Tips for automation prompts

* **Scope the batch explicitly** — name the folder, file list, or assembly, and confirm the count before running. This catches an over-broad or under-broad selection before it touches the wrong files.
* **Validate on one file first** — for a new rule, run it on a single representative file and check the result before applying it to hundreds of files.
* **State what should not change** — "leave the originals untouched", "don't touch files already at revision C" — batch operations are only safe when the exclusions are explicit.
* **Ask for a per-file report** — request a table of what happened to each file, not just a summary. Batch failures are usually a handful of edge-case files, and you need to know which ones.
* **Save recurring jobs as skills** — if you run the same batch operation more than once, save it as a skill. Reusing it by name is faster and more consistent than re-describing the steps each time.