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.


chans59 (author)2017-03-14


chans59 (author)2017-03-14

Wow!That's Great

AmylouK (author)2012-11-14

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!

stumitch (author)2012-04-22

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!

LanceMakes (author)stumitch2012-04-22

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!

stumitch (author)LanceMakes2012-04-22

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

hungyhipo 2 (author)2012-04-21

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

LanceMakes (author)hungyhipo 22012-04-21

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

hungyhipo 2 (author)LanceMakes2012-04-21

i wish my teachers were that awesome

Hiyadudez (author)2012-04-14

I don't build any of your project (Nothing personal :P), but I still watch the tutorials all the way through.

Your voice is brilliant and your instructions are super clear and easy to follow. I would follow you, but I already am :D

LanceMakes (author)Hiyadudez2012-04-15

Wow, thanks for the feedback - It's always hard to judge one's own Instructables, so it's great to hear that it's working :)

rimar2000 (author)2012-04-15

Great job, congratulations!

mikeasaurus (author)2012-04-14

These look great! It looks like all the kids had fun, awesome!

About This Instructable




Bio: I'm a writer, maker, and educator. For free lesson plans and teaching materials, check out
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