# Parts built feature by feature (Lab)

> In our lab, an AI agent models parts the way an engineer would, then changes them through their own dimensions and variables.

Status: Lab · Canonical: https://paracrux.com/docs/lab/parts-built-feature-by-feature

Lab: shown in demos and case studies, not for sale. This page describes what we are building, not something you can buy.

## What we are building

- Fully defined sketches and named features, with equations tying dependent features to the dimension that drives them. On the CR-110 connecting rod, the centre distance drives the small end.
- Real SOLIDWORKS features: fillets, I-beam pockets, Hole Wizard counterbores, an oil hole and a split cap.
- Assemblies mated from the parts' own design intent. The V8 rotating assembly reuses the CR-110 rod and turns on one mate, with every piston where the maths puts it at 11 crank angles.
- A design copied to a new size by changing its variables: the V8 went from 3.5 L to 5.0 L by changing stroke, bore and the rod's centre distance, measured back from the model.
- A design from a written brief, sized by hand calculation, checked, then changed: ScoutCrux 500, a folding drone of 112 components, became a 650 through its parameters.

## See it

- Recording: [Connecting rod: modelled, drawn, then changed](https://paracrux.com/demo#recording) (LAB RECORDING · 29 SEP 2026)
- Recording: [V8 rotating assembly: built, turned, drawn, then copied to 5.0 L](https://paracrux.com/demo#v8) (LAB RECORDING · 30 SEP 2026)
- Recording: [ScoutCrux 500: a folding drone, designed, checked, then changed to 650](https://paracrux.com/demo#scoutcrux) (LAB DEMO · 1 OCT 2026)
- [The CR-110 feature tree, step by step](https://paracrux.com/demo#build)
- [Turn the ScoutCrux model and read its record](https://paracrux.com/demo/scoutcrux)
- [What ships today, and what's still in the lab](https://paracrux.com/demo#today)

## What it is not, yet

- It is not in the Agent you can buy. Today the Agent creates only simple box parts from dimensions you state.
- In every recording an AI agent drives SOLIDWORKS through its API in our lab, which is not how the shipping Agent works.
- The recordings are edited: stretches where SOLIDWORKS was computing are cut, and some scenes are sped up or captured frame by frame. Each recording's note says how.
- Lab results are not engineering sign-off. ScoutCrux has not been built or flown, and one of its requirements fails: folded, the 650 is too long for the original case.

## What you can do today

- [Create a simple part from a brief](https://paracrux.com/docs/create-a-simple-part.md) (Available): Describe a block with all three sizes and get a checked native part and STEP file. Leave a size out and it asks.
- [Change a dimension on a copy](https://paracrux.com/docs/change-a-dimension-safely.md) (Available): Propose a new value, run it on a copy, check the result independently, then accept or reject. Your original is never touched.

## Covers

- Feature-by-feature parts (Lab): Parts built with fully defined sketches and named features, as in the connecting rod recording.