> [HTML view](https://gyropup.com/site/pages/docs-architecture-md.html) · [Markdown index](https://gyropup.com/llms.txt). Generated from the same published content. Interactive controls and 3D scenes are available in the HTML view.

[← Design notebook](https://gyropup.com/site/)

BUILT BY AUTONOMOUS SYSTEMS · WORK IN PROGRESS

# How Gyropup is engineered

One robot (D36), built and tested in pieces: one leg on a test rig, the turret on a bench stand, then the body around two legs. Each piece goes through the same chain, and every step writes files the next one reads.

```mermaid
flowchart LR
    G[Geometry sweep<br>tools/leg_synthesis.py] --> CAD[CAD<br>cad/fivebar.py<br>cad/turret.py]
    CAD --> B[Build: parts, assembly,<br>clash sweep, print plan,<br>parts list<br>cad/build_leg.py]
    CAD --> S[Physics: the test rig<br>sim/leg_rig.py]
    S --> L[Peak loads<br>exports/leg/rig-results.json]
    L --> F[Strength, every printed part<br>and the whole leg<br>cad/leg_studies.py]
    F -->|too weak or too heavy| CAD
    B --> P[Print and buy]
    F --> P
    P --> T[Build it, test it on the rig,<br>feed the measurements back]
```

## The pieces

| Step | Code | Writes | What it checks |
| --- | --- | --- | --- |
| Geometry | `tools/leg_synthesis.py` | `exports/leg/synthesis.json` | Push force at the motors' 60 N·m cap over the whole working range, joint angles away from dead points, links short enough to print |
| CAD | `cad/fivebar.py`, `cad/gmi.py` | (parts in memory) | Every printed part a single valid solid; bought parts at their real sizes |
| Build | `cad/build_leg.py` | `exports/leg/*.step`, `*.stl`, `leg.json`, `print-plan.json`, `bom.json`, pictures | No part touches another from crouch to full height and ±20° of lean; every part fits the 256 mm bed |
| Physics | `sim/leg_rig.py` | `exports/leg/rig-results.json`, `rig_*.mp4` | Stand, squat, jump, drop, power loss: motor torque and speed, axle force, link forces, stop loads |
| Strength | `cad/leg_studies.py` | `exports/leg/fea/` | Safety factor 2 everyday and 1.2 in rare events on humid printed PA6-CF; overload videos and the interactive 3D view |
| Turret | `cad/turret.py`, `cad/build_turret.py` | `exports/turret/` | The turret's parts, its ball path, its clashes, the bench stand |

The interface standard (`docs/mechanical-interfaces.md`, `cad/interfaces.json`) keeps the motor-specific parts (output adapters, motor seats) apart from everything else, so a motor can change without redesigning the links.

## What the numbers rest on

-   Motor data from RobStride's drawings and STEP (lug pattern, output flange), the BotWheel from ODrive's drawing.
-   Printed-material allowables: Bambu's dry PA6-CF data, times 0.6 for humidity and 0.8 for print defects.
-   Estimates, flagged where they are used: the RS-04's rotor inertia (it sets how hard a landing is), the BotWheel tyre's stiffness, the RS-04's power-off damping. The test rig measures them.

Simulation and FEA do not prove that a part fits or holds: the rig and the bench do. The old serial-leg robot's pipeline (`cad/build.py`, `sim/model.py`, the 3D game page) stays until leg v2 is on the full robot.

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