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.

The gearing ratio of the 2nd gear of the 2 speed automatic gearbox can be set using a manual 4 speed gearbox to choose between gearing ratios relative to the first speed of 0.865, 0.775, 0.595 or 0.325.

The 2 speed automatic gearbox car is tested to see how well it drives up a steep hill, and is also compared to a lego manual gearbox version of the car to see the performance difference.

Finally the construction of the 2nd speed implementation using a differential is compared to a basic construction for the same gearing ratio by measuring their torque output by pulling a set of rubber bands and measuring the overall force generated.

#technicbrickpower, #legotechnic.

[jbw_]

Just gave the 100 like and there's still no dislike - wow!
Cool idea that force detector and nice explaination, go on like this!

[sebastiannowak]

I really like your scientific approach and explanation keep up the good videos👍

[Sirslayer_X]

Darn, and I was cheering for you . Next time!!!

[danifromch]

I built this gearbox (with some different ratios) and it's very cool. Seldom seen such a smooth thing. But yes, torque does not seem to be better. I don't think because of friction, I guess because the direct input on the differential is the weaker one. If you subtract speed via wormgear, the direct input stays at the same «weakness».
But the idea is so nice, there must be a solution to bring the two input lines together, without having the direct line fighting against wormgear line ✌🤔🤓

[johansten]

When you had the test setups done I thought you were going to put them through the Friction comparison build you showed a while back, but this was even better!

[valentinomanontroppo]

so in the set up at 7:25 you should switch places between the black cogs on the left and the light gray cogs on the right, making the main input of the differential the slower one, and repeat the pulling experiment

[redesigndp]

Great video! I like your scientific analysis. P.S. you must have a crap load of legos..

[arkadygorodischer]

Hey, thanks for the video!! Just what about my question was asked.

Actually, an automatic gear box looks like a Holl grail for the lego. Many tries to find a solution, but as far as I can see, you are the closest one to find it. Keep going!
How can I support you, beside the subscribtion to your channel?

[SaperPl]

Pretty cool. Keep it up.

I actually thought you're going to go with it and was like "how the hell is this subtraction going to work?"
Cool you did test in on reasonable slope . From my understanding, the subtracting method seems to throw away the portion of torque/speed that is being negated/subtracted from each side of the mechanism. That is why a lot of concepts for automatic gearboxes end up working great for the speed, but not necessarily for the torque.

Also additional opposite problem to this one. Lets say you have a model heavy enough so it won't move on the fast gear, have you tried using the gearbox in such scenario? Or even better figuring out a way to start from slow gear even when you don't necessarily have the weight or slope preventing the move, but we want the model to start with low gear and slowly climb up the speed.

Anyway, I'm tuned in.