Software
Onshape
⚠️

This documentation is under construction and incomplete. Please sign up here for K-Scale updates (opens in a new tab) and check back later for our progress.

Onshape to URDF Converter

kol is what we use at K-Scale for interacting with OnShape. It is a wrapper around the OnShape API that allows us to easily import parts, postprocess them, and export them in a variety of formats. This is a key part of our mission to make robots more accessible --- Onshape is free, easy to use, and encourages open-source development through FeatureScript.

In a single CLI, we support functions such as mesh simplification, mesh merging, joint cleanup, transferring between MJCF/URDF formats, and more.

Installation

pip install 'kscale-onshape-library[all]'

Usage

The KOL CLI provides several subcommands for different operations:

kol <subcommand> [options]

Available subcommands:

  • run: Download from Onshape and post-process
  • download: Only download from Onshape
  • postprocess: Post-process an existing URDF
  • pybullet: Run PyBullet simulation

Download and Post-process

To download a model from Onshape and apply post-processing:

kol run <onshape-document-url> <output-directory>

To see additional configuration options, consult the config file here (opens in a new tab).

Download Only

To only download a model from Onshape without post-processing:

kol download <document-url> <output-directory>

Options are similar to the run subcommand.

Post-process Existing URDF

To apply post-processing to an existing URDF file:

kol postprocess <urdf-path>

PyBullet Simulation

To run a PyBullet simulation with the processed URDF:

kol pybullet <urdf-path> [options]

Options:

  • <urdf_path>: Path to the URDF file to simulate (required)
  • --dt FLOAT: Time step for simulation (default: 0.01)
  • -n, --hide-gui: Hide the PyBullet GUI
  • --no-merge: Do not merge fixed links
  • --hide-origin: Do not show the origin of the robot
  • --show-inertia: Visualize the inertia frames
  • --see-thru: Use see-through mode for robot visualization
  • --show-collision: Show collision meshes

Examples

  1. Download and post-process an Onshape model:
kol run https://cad.onshape.com/documents/... ./robot
  1. Post-process an existing URDF:
kol postprocess ./path/to/model.urdf voxel_size=0.005
  1. Run PyBullet simulation:
kol pybullet ./output/model.urdf
CLIE-VLA