Propeller-Powered Zipline Racers





Introduction: Propeller-Powered Zipline Racers

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How It Works
It's simple. Winding the propeller will store energy in a rubberband by twisting it. When released, the propeller rapidly unwinds and generates thrust, which pulls the craft along a low-friction zipline. However, the torque from the unwinding propeller can cause the entire racer to flip upside down. To counter this force, another force is introduced: drag. By attaching a paper cutout, drag perpendicular to the side of the racer is created, which helps prevent inversions.

Safety and Tips

  • CAUTION! Pulling downward on the racer while it is hooked onto the zipline may cause it to be flung off the line upon being released. This can be dangerous when the propeller is rapidly unwinding. Be sure to directly supervise each student at least once as they attempt to launch their racer for the first time. Be sure to correct anyone who pulls on the zipline before a launch.
  • Make sure the zipline is either highly visible or above everyone's head.
  • Young students (grades 1-3) may need extra guidance while bending the paperclips, attaching the rubberbands, and properly launching the racer.
  • Encourage your students to experiment, especially if they're in grades 4 and up - I'm always amazed by their innovations and improvements.

5 People Made This Project!


  • First Time Author Contest 2018

    First Time Author Contest 2018
  • Sew Warm Contest 2018

    Sew Warm Contest 2018
  • Gluten Free Challenge

    Gluten Free Challenge

We have a be nice policy.
Please be positive and constructive.




I made it for a science project.

My friends pictures are above me!!!!


Wow!That's Great

Hi there! I'm an Elementary Ed student and I'll be using this to present a lesson on push and pull to my peers. You have some really great ideas and I'm sure we'll have a blast! Thanks!

as a shop teacher of 14 years i have to say what a GREAT job you've done! i am already in the process of stringing a line in my shop! thanks!

Much appreciated :) I've admired many of your projects from the teacher contest - keep up your superb work and imagination!

oh, and if you can, please post some photos if you try out this project. Thanks!

thanks for the kind words! i'll post photos or email them if you'd like.

If you are a teacher (which I'm pretty sure you are) you are probably one of the coolest.

Thanks! I do my best to create a fun atmosphere for kids to learn in :)