Climb Every Mountain with Your Own LEGO® Cable Car *

Areas of Science Robotics
Time Required Short (2-5 days)
Prerequisites You should be familiar with programming for LEGO Mindstorms to do this project.
Material Availability This project requires a LEGO Mindstorms EV3 kit (available from or a LEGO Mindstorms NXT kit.
Cost Very High (over $150)
Safety Make sure your cable car string is securely attached to a heavy object (like a table or large chair) at both ends. The Mindstorms bricks are heavy, and could fall and damage your LEGOs or other objects if the string is not securely attached.
*Note: This is an abbreviated Project Idea, without notes to start your background research, a specific list of materials, or a procedure for how to do the experiment. You can identify abbreviated Project Ideas by the asterisk at the end of the title. If you want a Project Idea with full instructions, please pick one without an asterisk.


If you ever rode in a cable car, ski lift, or gondola, you know they make moving over obstacles like lakes, valleys, rivers, or even up steep mountains seem easy. Though it would be pretty difficult to build a full-size cable car in your home, if you have a Mindstorms® kit, you can build a working-model cable car of your own. The engineering challenge is to build a LEGO® cable car that can travel across a string you have suspended somewhere in your house (between two pieces of furniture, for instance). If you want to make the project even more challenging, you can try to design the cable car to travel up a steep string, just as a real one would go up the side of a mountain (for example, you could tie one end of a string to a window frame and the other to the leg of a chair). For an added robotics challenge, you can add sensors to your cable car — using the Mindstorms NXT or EV3 ultrasonic, light, or touch sensors to enable the cable car to detect when it reaches the end of your string, and then reverse direction.

Figure 1 shows a LEGO cable car built by the Science Buddies staff.

Robotics Science project Robotic LEGO NXT cable car
Figure 1. The Science Buddies cable car — complete with a passenger seating area (middle), operators (top right), cargo area (bottom left) for luggage (the pirate brought his treasure chest), and a hitchhiking monkey (top).

Here is a video of the cable car in action:

This video shows the Science Buddies LEGO cable car traveling across a string between two pieces of furniture.

Because this is an abbreviated project idea, we will not give away the details on how exactly we built or programmed this cable car — that is up to you! If you need help with programming, we have included some resources in the Bibliography that may be useful. Remember that you can tackle this problem in many ways, so do not feel as if you need to reproduce the cable car as pictured in Figure 1 and in the video. You could build something completely different that works just as well, or even better!

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Ben Finio, Ph.D., Science Buddies


  • Thanks to Tufts University Center for Engineering Education and Outreach ( for this project idea.
  • LEGO® is a registered trademark of the LEGO Group.

Cite This Page

General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

Science Buddies Staff. "Climb Every Mountain with Your Own LEGO® Cable Car." Science Buddies, 2 Apr. 2018, Accessed 20 Oct. 2019.

APA Style

Science Buddies Staff. (2018, April 2). Climb Every Mountain with Your Own LEGO® Cable Car. Retrieved from

Last edit date: 2018-04-02


The following resources may be helpful with programming LEGO Mindstorms. (Which particular resource is helpful to you will depend on which programming language you use.)

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