# How do you make a 1:3 gearing ratio?

A 1:3 gearing ratio means the input gear rotates 3 times for each rotation of the output gear - hence you need the number of teeth on the output gear to be three times the number of the input gear. The most common way to pair up an 8 tooth gear and a 24 tooth gear as shown in the diagram below. **Note**: the distance between axles is 2 lego units:

There is another ratio of gears that make a 1:3 ratio and that is driving a 36 tooth bevel gear with a 12 tooth bevel gear as shown in this example:

The main difference between these two options is that the first option has a spacing between the axles of 2 where as the second solution has a spacing of 3. So sometime one can be preferable over the other to be able to design a gear chain that suits your needs. Another benefit of the bevel gear solution is the option to drive another gear off one of the bevel gears at a 90 angle allowing you to create a gear chain with a turn in it.

# More to explore

## New Flat 12/20 Gear Friction

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

### Gearing Ratio Calculator Tool Help

## Measuring Gearbox Efficiency

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

## Lego Technic Gearing Ratio Tool Update

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 do you make a 1:4 gearing ratio?

### What is a gearing ratio?

## Lego Technic Gearing Ratio Calculator Tool

Here I present my new Lego Technic Gearing Ratio Calculator tool. This tool allows you to upload your Lego Technic .ldr (Lego Draw) file and it will simulate the gearing system and visualize it as well as showing the gearing ratios relative to the input component.

The tool can be accessed...read more

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

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