The fastest Lego Lok of the World

[uefchen]

Here is my latest idea for you.

It is not a roller coaster!

The fastest Lego Lok of the word

Locomotive (also abbreviated Lok), generally a railway self-propelled, which one uses to train or thrust of rail vehicles. From other rail vehicles with own drive, the locomotive is different in that it is provided only as a prime mover and not for the transport of passengers or freight.

​by üfchen

[DanSto]

Interesting and funny.

As asked on Youtube, how do you come to 70 km/h ?

A falling object (without friction) only accelerated by the gravitation has to fall 19 m to reach such a speed following the mechanical energy conservation : m.v²/2 = m.g.h giving h = v²/(2g). Your height seems to be around 2 m so that the final speed is something like 6 m/s = 23 km/h. OK, we have to add the initial speed but it seems to be relatively small ;).

[Dutchiedoughnut]

Don't forget to factor in wind resistance which will get serious by 70 kph... lets go find the tallest building!

[DanSto]

Of course, if you take the friction and the wind resistance into account, you will need a higher fall to reach 70 km/h

[Rail Co]

I assume it could be scale speed though right?

[Dutchiedoughnut]

I have to say the execution is impressive :). I guess you could build a speed trap at the bottom of the loop and time how long the train is actually in the loop itself? That should give you an average speed for the fastest section of the "railway".

[LEGO Train 12 Volts]

It's always fun see your impressive and original works!

Amazing project and lovely video game music!

[DanSto]

I have to say the execution is impressive :). I guess you could build a speed trap at the bottom of the loop and time how long the train is actually in the loop itself? That should give you an average speed for the fastest section of the "railway".

The fastest speed is reached at the end of the slope and just before entering the looping. This is why I used the simple conservative mechanical model were potential energy m.g.h is converted into kinetic energy (1/2).m.v² giving v = SQRT(2.g.h) : you see that the weight and the slope of the track does not play a role. So for h = 2 meters, you have a speed around SQRT(40) nearly equal to 6 m/s = 23 km/h which remains far from the 70 km/h .

[Dutchiedoughnut]

True, but the train has a motor adding to its speed. And I just want to know the speed rather than calculate it ;)

[Severus A]

Fast and funny. The installation is impressive.

[DanSto]

True, but the train has a motor adding to its speed. And I just want to know the speed rather than calculate it ;)

If you look carefully at the video, you will see that the third black track for the traction is not present at the slope and the looping. So the motor does not help (it would in fact break) and only the gravity pulls the lok. My calculation fixes the mechanical limit.

I would like to know how he came to 70 km/h because it looks overestimated.

Edited April 30, 2016 by DanSto

[xboxtravis7992]

When I first saw the word "locomotive" and "terminal velocity" in the same sentence before I watched the video, I was afraid I was going to see something else...

Great mechanism. Love the loop!

Also to get an exact calculation on the speed, don't model railroading companies make speedguns for scale trains? Might get the best result.

Edited April 30, 2016 by xboxtravis7992