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

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

This video presents a lego technic 3 speed automatic gearbox design that failed to work as expected. This design is based on an earlier design of a 2 speed automatic gearbox with smooth transmission that worked very well.  That technic gearbox was extended by adding another speed to the oran...read more

Here a Lego Technic 3 speed automatic gearbox is presented. The gearbox automatically switches between one of 3 gear ratios, namely a ratio of 1, 1/3rd and 1/9th depending on the load on the output.  It uses two 2 speed automatic transmissions in series to create the three speed automatic ge...read more

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.

The ...read more

This video presents the relationship between lego technic motor torque and speed and shows there is an peak power for each electric motor.

The peak power is calculated and a formula presented relating the power operating point as a percentage of peak power. From this an operational power ...read more

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

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.

This 2nd speed is added to the mai...read more

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

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