model j labs
Model J Labs / J Simulation 0.1.0

A room for
engineering experiments.

Import your parts into a standalone 3D assembly workspace. Explore forces, motion and mechanisms, with explicit assumptions and exportable studies.

Independent from Aether. This complete desktop application includes its runtime and CAD evaluation tools. Aether does not need to be installed. Existing .aesim studies remain supported.

Install J Simulation.

A free Model J Labs account is required to download.

0.1.0 engineering preview

Windows x64

Windows 10/11. A complete .exe installer with Start Menu shortcut and uninstaller.

Download Windows installer ↗

Unsigned preview. Actual Windows installation and GPU testing remain pending.

0.1.0 engineering preview

Ubuntu Linux x64

Ubuntu 24.04 LTS. A .deb package with applications-menu integration.

Download Ubuntu installer ↗

Requires a graphical desktop and graphics drivers. Other distributions are not packaged yet.

Your own study files

Launch directly into the 3D room. Import STL, OBJ, 3MF, GLB or .aecad, choose units and assign physical properties. Save and reopen .aesim studies locally.

Installer checksums

Know what is being calculated.

3D assemblies

Rigid bodies, gravity, convex-hull contact, friction and constant applied forces. Holes and concave cavities are filled by collision hulls; materials do not deform.

Mechanisms & loads

Ideal gear ratios with reflected inertia and resisting torque. Analytical cantilever bending. Neither mode calculates CAD tooth contact or finite-element stresses.

Experimental flow lab

The inherited solver remains 2D laminar flow at Re 5–200. It does not simulate 3D wings, turbulent flow, free-surface water or rocket aerodynamics.

Professional 3D CFD integration and application-specific validation are future development. This release is an experimental foundation, not validated evidence for critical engineering decisions.

Quick start

  1. Open J Simulation: the 3D assembly room is the default.
  2. Choose Loaded assembly to explore an example, or import multiple CAD meshes. Set units before importing STL/OBJ.
  3. Select each part and enter placement, mass, friction, supports and forces. Run, pause or step the study.
  4. Save a .aesim file and export results. Existing Aether simulation files open in this standalone application.