Lego Technic Two Degrees of Freedom 2 speed Automatic Gearbox
This lego technic 2 speed automatic gearbox implements it's second gear by using a two degrees of freedom configuration and blocking and unblocking the lower gearing ratio path by using a switch and rotary catch. The rotary catch is driven by a torque detector and once enough load is detected at the output it is rotated 90 degrees to unblock the low gearing ratio path. Upon the path being unblocked it becomes the path of least resistance and the output gearing ratio is reduced to give a higher output torque.
Alternative lower gearing ratios can be implemented in this lego technic 2 speed automatic gearbox by changing out the lower gearing path gears.
This 2 speed automatic gearbox operates in a bi-directional manner - meaning the input motor can rotate either way and the automatic gearbox still functions.
More to explore
Lego Technic torque in practice - how to work with torque in automatic gearbox design
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 car. Part 1
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.
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Lego Technic Gearbox Theory Applied - how to apply theory to help design 2 speed automatic gearboxes
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 smoothly switching 2 speed automatic gearbox evolution with instructions
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.
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Lego Technic 2 Speed Automatic Gearbox - Compact! With build Instructions.
Here I present a design for a compact lego technic 2 speed automatic gearbox. Instead of using a differential to react to torque on the output it uses the force on the gear teeth to push a liftarm to automatically change the gearing ratio to the 2nd speed once the torque threshold has been ...read more
Lego Technic Automatic Reversing Gearbox MOC with Instructions
This lego technic gearbox has been designed to automatically reverse if there is a high load on the output. For example you may have a car that drives into a barrier and it will start driving backwards to avoid it. The MOC gearbox works by using a differential to react to the torque on the output...read more
Lego Technic 3 Speed Automatic Gearbox
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Lego Technic Powerful 2 Speed Auto Gearbox
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
Gearing Ratio Calculator Tool Help
Lego Technic Servo Driven 3 Speed Automatic Gearbox
A lego technic 3 speed automatic gearbox is presented using a lego technic power function servo motor to drive the gear change mechanism. The servo motor is driven by a lego electric switch which in turn is driven by a torque detector using a differential at the output.
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