LEGO Automatic Continuously Variable Transmission

One thing I'd like to see would be the same car chassis trying to navigate the same obstacles, but with a basic transmission, just to get a frame of reference for how the continuously variable transmission is actually solving a problem that the basic transmission would simply fail at.

I’d say this is more similar to a torque converter and not a cvt transmission. A cvt will basically change the gearing by changing the size of the pulleys that the belt connects to. A torque converter will slip and different amounts to create more or less torque. I hear that the motor was struggling under load. A cvt is nearly 100% efficient so if it was a cvt it would not struggle like that. Instead the pitch of the motor would stay the same and would just lift the load slower

Love the idea, I would instead reverse the transmission to make your creation go faster! Torque is a good way to show how it works, but if you can make a lego car that can go from snail to rocket that would be awesome!

The only thing this channel needs is more cool content.

The problem with this, and ALL other differential based "automatic transmissions" is the huge loss of energy from the system having to overcome a resistance to shift torque. In this case its the rubber band slipping. The "resistance" is the torque required for the pulley to slip. Another design I've seen uses a friction pin with an 8 tooth gear. About half the energy of the motor is lost with this method. In my channel you can see a LEGO speedometer that works on a similar principle, but it can be attached to the drivetrain, but not be part of it, thus you can measure the speed without losing half of the motor's energy

I can't believe how far we've come in the world of lego CVTs. It was only a few years ago that a small scale prototype was almost impossible, now we've got this.

It must be a strange feeling when you push against the vehicle and you feel it respond by pushing harder against you

This works in a similar manner to an automatic gearbox I made and has the same modular capabilities, very cool!

Really cool project, great video format. Hope to see more!

Hub van Doorne would have loved to see this, my Volvo has a continuously variable transmission. Keep up the good work, this might become a (LEGO) technically very interesting channel!

This isn't an actual CVT, the ratios between the two pulleys aren't actually changing. Yes, the second pulley is moving slower, but that's just because the belt is slipping. Any gain in transmitted torque can be explained by a combination of the extra tension pulling the rubber band into the secondary pulley plus localized heating of the rubber band at the point of contact generating more grip, plus the momentum of the primary side dragging it a little harder in pulses.

It’d be great to see this car and another car compete at a sled pull or similar heavy object pushing contest

this channel Is alot better than people think

The first design is fairly similar to how Toyota hybrid CVTs work, but those have an electric motor instead of a band to adjust the gear ratio.

Very good content ❤ Wish you all the best and keep it up 👍🏻

This is a great representation of how to do science correctly, that it is quantitative and the results from data is how we end up in a conclusion. Great job!

A real cvt though uses a cone shaped pulley that moves and a v- belt. You change the distance between the cones to increase or decrease the size/ ratio.

this paractice gear system is incredible

This video is great, thank you!

YESSIR!!!! Finally another good channel. I have to subscribe