Spherical Folding Propeller

A compact automatic folding spherical propeller

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This is my 3d-printed propeller that folds into a compact 16mm diameter semi-sphere. When rotated the two blades open up automatically by the centrifugal force. The blades will then fold back into the semi-sphere once the motor is stopped.


  • 2 × SMF681X-ZZ bearings
  • 2 × 16mm diameter 3D-Printed blades
  • 1 × 3D-Printed bearing holder

  • How i came up with the idea?

    Carl Bugeja07/15/2018 at 06:24 0 comments

    This is the drone concept that gave me the idea of trying to create the PCB motor and spherical folding propeller! Both of these projects need a lot more work and improvement to make this drone feasible but at least now I have a starting point :)

  • Thrust Test

    Carl Bugeja03/25/2018 at 21:13 0 comments

    This is the thrust results of the first Spherical Folding Propeller prototype:

    The results are not so bad considering the size of the propeller (1.6cm diameter when folded) and that no air-flow simulations were done during design. I'm going to conduct simulations for the next prototype, to try and make the propeller as efficient as possible.

    This is the setup used to measure the thrust. The propeller was suspended around 15cm above the scale, to eliminate ground effect.

  • First Test

    Carl Bugeja03/23/2018 at 00:25 0 comments

  • Dimensions

    Carl Bugeja03/23/2018 at 00:24 0 comments

    The first prototype has a sphere of 16mm diameter. When the blades are opened, the propeller has a total length of around 3.7cm. Its total weight is around 0.6 grams.

  • Assembly

    Carl Bugeja03/22/2018 at 23:12 0 comments

    The first Spherical Folding Propeller prototype is made from:

    • 1 3D-Printed Bearing-Holder
    • 2 3D-Printed Blades
    • 2 SMF681X-ZZ Bearings

  • First 3D-Printed Prototype Parts

    Carl Bugeja03/22/2018 at 23:06 0 comments

View all 6 project logs

Enjoy this project?



Mohsen Abbasi wrote 03/30/2018 at 14:49 point

Hey man, the design is nice but .. the idea of the shape is not. Ther are lot of reasons why the propellers are like what you see today. Your design is one of the first trys in the human history.

So, now, use the folding mechanism and try to use it to a working propeller. This will be mch better.

  Are you sure? yes | no

Carl Bugeja wrote 03/30/2018 at 15:07 point

Totally agree :) This first prototype was more of a concept to validate the automatic folding and unfolding of the propeller and experiment with the idea.. next step would be to make the propeller as efficient as possible 

  Are you sure? yes | no

Mohsen Abbasi wrote 03/30/2018 at 15:18 point

good luck. I new type of foldable propellers is really needed

  Are you sure? yes | no

deʃhipu wrote 03/23/2018 at 21:38 point

This looks interesting. Can you elaborate on advantages of such a design, compared to the more traditional propellers? Apart from a cool looks, that is.

  Are you sure? yes | no

Carl Bugeja wrote 03/24/2018 at 16:06 point

The idea behind this spherical prop design was to allow a drone to be easily placed in a pocket/bag without worrying of bending or breaking its propellers. My aim is to make it fold and unfold automatically. 

  Are you sure? yes | no

deʃhipu wrote 03/24/2018 at 16:23 point

I see. I wonder if it would be possible to make it have better aerodynamic properties than right now at the same time.

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Wade Bortz wrote 05/01/2018 at 22:15 point

As someone who often crashes my micro drone, an automatic crash detection and quick reverse thrust might be useful. This could even be used like a sparrow folding it’s wings when it flies though small gaps - useful to dart through tree branches.

  Are you sure? yes | no

Carl Bugeja wrote 03/24/2018 at 17:58 point

I'm currently testing its thrust and comparing it to other propellers in the same size range.. More info coming soon :)

  Are you sure? yes | no

Isaac S. Gentry wrote 04/13/2018 at 23:36 point

I think that it would be great for rubber band powered free flight models because when the rubber band runs out of energy, it would fold, reducing drag. 

  Are you sure? yes | no

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