Gearing Ratio Calculator

Check out the Beta version my Lego Technic Gearing Ratio Calculator Tool:

This tool allows you to upload your Lego Technic project .ldr file and analyse the gearing ratios between any two connected gears or axles. Currently supports most gears, axles, worm gears, some differentials, cv joints and universal joints. See the video tutorial on how to use it. It is a work in progress and I would love to hear your feedback on it. Click here to try it out.

Note: As of 25 Septemeber 2021 the tool supports CV joints, linear speed via the radius of the component and improves on the frame rate for higher numbers of parts in a model).

Technic Elbow Art

This is a tool to create "Lego Technic Elbow Art" - a series of intertwined elbow pieces as a single sequence. Choose your dimensions and search parameters and search for new dense solutions and set a record! 

Download your Elbow Art as an .ldr file and build it yourself. Click here to try it out!

What software tools support LDR files?

16 Jul 2021

Pretty much all of the Lego Design tools available support the LDR file format. Usually each tool also has it's own proprietory format for storing design files. Some software I know about are:

Bricklink Studio

Studio is a nice Lego design program developed by bricklink. It supports Windows and MacOS. Bricklink studio produced photo realistic renders and videos (I use this for some of my youtube video introductions),


This is an open source Lego Designer supporting Windows, Linux and MacOS. It is currently an active project with new features being added all the time.

Lego Digital Designer

This software is from the Lego company itself! Unfortunately they have stopped maintaining it, however you can still download and use it. Supports Windows and MacOS.