TOOLS

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!

How do you make a 1:5 gearing ratio?

7 Sep 2021

To create a 1:5 gearing ratio you need to connect two gears where one gear has five times the number of teeth as the other. One such lego technic combination is an 8 tooth gear driving a 40 tooth gear as shown in the diagram below. There is no other pair of gears that have a 1:5 ratio (except a 12 tooth driving a 60 tooth turntable but that is not a regular gear).

The 40 tooth gear is quite large and may not fit into your lego technic model easily. Another more compact method is to create a gear train by driving a 20 tooth gear with a 12 tooth gear to create a 3:5 gearing ratio and then to follow that with a 1:3 ratio made from for example an 8 tooth gear driving a 24 for tooth gear. So this creates an overall gearing ratio of 3 / 5 x 1 / 3 = 1 / 5 or 1:5.

The advantage of this solution is that it gives you more flexible layout options in terms of the axle spacings. In this design there is a 4 lego unit linear distance between the input and ouput axles, however you can also arrange the gears in an L shape to give a (2,2) spacing between the input and output axles.

Other solutions exists, however these solutions are the most common and practical.

 

More to explore

Lego Technic Gearing Ratio Tool Update

4 Sep 2021

This video presents updates to the Technic Brick Power Lego Technic Gearing Ratio Calculator tool specifically on underconstrained differential systems. These are systems in which the differentials are not fully constrained and therefore have 1 or more degrees of freedom within them.

The ...read more

How to mesh any two Lego gears on a regular grid!

22 Aug 2020

In this video I analyze all of the eight regular lego technic gears and demonstrate how any two of them can be meshed on a lego grid.

A sum of radii chart is used to determine the possible diagonal meshing combinations. These are then combined with "intermediate" or "idler&...read more

New Flat 12/20 Gear Friction

23 Apr 2022

The Lego Technic set 42140 App-Controlled Transformation Vehicle introduces two new gears - a flat version of the 12 tooth bevel gear and a flat version of the 20 tooth bevel gear. These gears are designed to have less friction.

In this video I measure the difference in gearing efficiency...read more

Lego Technic Pi Day Machine

14 Mar 2022

 

Here I present a Pi Day special Lego Technic machine that produces a gearing ratio of Pi/8 using a 56mm wheel driving a 13x13 square wheel.

The correctness of the ratio is confirmed by matching it with output of a 2 differential gearing system that produces a ratio of 355/9...read more

Measuring Gearbox Efficiency

6 Nov 2021

This video describes a method for measuring the efficiency of a gearbox using the Lego Technic Powered Up hub. Gearbox efficiency is defined as the ratio of the output power to the input power and here I show how to measure each of these values to allow you to calculate the overall efficiency.read more