# Lego Technic Measuring Gear Backlash

Lego Technic gear backlash, also known as gear slop, gear play or simply gear lash is explained and demonstrated. The idea for this video came from a previous lego Technic design that exhibited problem causing gear backlash. The angle of lego technic gear backlash depends on the air gap and the number of teeth on the gear. It is measured for 16 tooth gears using a chain of thirty-one gears and measuring the cumulative angle and dividing by the number of gear meshes.

# 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

## 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

## How to measure a Lego Technic Crane's Efficiency. The results surprised me!

Here I demonstrate how to measure the efficiency of a Lego Technic MOC crane using basic physics. Efficiency is the ratio of the useful energy output (the potential energy put added to the weight) the to the input energy (power source power). The efficiency curve is interesting and does not look ...read more

## Lego Technic PU 2 Speed Automatic Gearbox

This video presents a lego technic two speed automatic gearbox using two motors and the Powered Up (PU) lego technic control system. Each motor uses a pivoting gear to either connect to it's gear to the left when rotating in the forward direction or to the gear to the right when reversing. Th...read more

## Lego Technic Pi Day Machine

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

## 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

### Gearing Ratio Calculator Tool Help

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

## 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