# 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!

# Lego Technic 2 Speed Auto Car Ramp Challenge - Part 2

10 Dec 2020

A lego technic 2 speed automatic gearbox is put to the test by incorporating it into a lego 2 speed automatic car.  This lego 2 speed automatic gearbox implements a number of design principles aimed at improving the gearbox performance - namely of placing the torque detector on a separate path to the main gearing power path to reduce torque and power losses in the lego gearbox, and using gear disengagement to switch gears instead of gear engagement.

A simple derivation is presented of the physics involved in driving up a ramp in order to determine the amount of additional torque required at the motor output to be able to overcome the gravity and the corresponding potential energy.

The  torque of the large lego power function motor is measured by measuring the output axle speed using a laser tachometer and relating that to the linear torque/speed relationship of the motor. These measurements are demonstrated for the car without any loading and with simple horizontal motion.

Finally the car is put to the test by attempting to drive up a 40 degree ramp.

# More to explore

## Lego 2 speed automatic car. Part 1

3 Oct 2020

This video explores the use of the lego technic "smoothly switching 2 speed automatic gearbox" inside of a test car to see how well it works to climb up a ramp.

The gearing ratio of the 2nd gear of the 2 speed automatic gearbox can be set using a manual 4 speed gearbox to choose...read more

## Lego Technic Powerful 2 Speed Auto Gearbox

3 Jun 2022

Here I present my design for a compact and powerful Lego Technic 2 speed automatic gearbox.

The gearbox uses the Lego Technic Powered Up functions to detect speed and deduce torque from that to make gear switching decisions. The gearbox switches between a high gear of 1 to 4, to a low gea...read more

## Lego Technic RC 3 SPEED CAR - change gears, drive and steer using remote control

19 Jan 2021

An improved version of a lego technic RC 3 speed gearbox is implemented into a remote control lego car. This video shows three main improvements over the previous gearbox design. The first is an improvement is to replace the 90 degree bugatti stepper  with a PF servo motor reducing the gearb...read more

## Lego Technic 2 Speed Auto Gearbox - a new hope - with build instructions

28 Nov 2020

This Lego technic 2 speed automatic gearbox design uses a worm gear for torque detection and gear switching combined. Previous Lego 2 speed automatic gearboxes have used a Lego differential for torque detection to drive an orange rotary catch to switch gears using a switch component.

## Lego Technic Gearbox Theory Applied - how to apply theory to help design 2 speed automatic gearboxes

10 Nov 2020

This video applies lego technic gearbox, torque, and gearing ratio theory to design a prototype lego 2 speed automatic gearbox. First I describe the main components of an automatic gearbox, namely a gearing ratio selector and a torque detector. The ideal gear switch over torque point is described...read more

## Lego Technic torque in practice - how to work with torque in automatic gearbox design

29 Oct 2020

n this video I present a ten level Lego Technic torque creation gadget for testing lego power function motors and automatic gear switching mechanisms. The effect of torque on a large lego PF motor is tested against the theoretical power curve to compare the optimal gear switching point in practic...read more

## Lego 2 Speed Automatic gearbox - worm gear prototype. Includes build instructions.

26 Sep 2020

This video present a lego technic 2 speed automatic gearbox based on using a worm gear for torque detection.  The 2 speed transmission gearbox works by using the linear counteraction force on the worm gear to connect a gear to create a second speed.

## Lego Technic smoothly switching 2 speed automatic gearbox evolution with instructions

11 Sep 2020

This video presents my latest compact and smoothly switching 2 speed automatic gearbox made out of Lego Technic.  It is both smoothly switching and compact.

The MOC gearbox automatically switches down in gearing ratio when the load on the output is sufficiently high by using a new te...read more

## LEGO Technic MOC: 1023 SPEED CAR

16 Jul 2020

A 1,023 speed gearbox has been built into a Lego Technic remote controlled car chassis. The car can be steered and driven via remote control using two channels. The gears can be manually changed using ten selectors that drive ten differentials. This allows for one of 1023 different speeds to be s...read more

## Lego RC car chassis with slow reverse gearing mechanism

8 Jul 2020

This Lego technic MOC car chassis is remote controlled with forward and reverse and remote controlled steering. What is different about this design is that it implements a special gearing mechanism that allows the car to drive forward at a normal speed, and 1/5 the speed in reverse. It uses a spe...read more