WAP – WARNING! Air Pockets


[25x30x40 cm, 165 parts, about 90Mb]


The Mechanism. WAP is a paper automaton whose main mechanism is Redtenbacher`s variation of the Cartwright straight-line mechanism, a twin gear driving a common slider crank. If the two gears have different but almost equal number of teeth, the up and down motion of the bar is then an addition and subtraction of two sinusoidal functions. The straight line generation, determined by the vertical motion of the bar, was a very important problem in the early history of mechanics. In WAP, the “random” motion of the unlucky airplane is generated at the center of the beam, that is free to spin. At that point, the two sinusoidal movements originate the oscillation that, together with the up and down motion of the bar, results in the air-pocket-like shaking up.

(further information at http://kmoddl.library.cornell.edu/index.php)


Cartwright mechanism

Redtenbacher's variation

Redtenbacher’s variation


The main mechanism in WAP is based on two gears with ratio equal to 1.2 (18/15 teeth). The entire cycle is completed after five turns of the handle.

Ferdinand Redtenbacher (1809-1863). The transformation of mechanical technology from a mainly workshop-based profession into an engineering science, particularly in the area of design of machines and mechanisms, is closely related with the name of Ferdinand Redtenbacher. He was of eminent historical importance for Porträtthe evolution of mechanical engineering to a technical science in the nineteenth century. Redtenbacher’s role as the originator of mechanical engineering as a science in Germany is fundamental and of general interest since the introduction of science into engineering is a “sine qua none” for the development of a powerful high tech industry. As a professor and the director of the Polytechnic School in Karlsruhe, Germany – today the University of Karlsruhe (TH) –, Redtenbacher’s influence therefore helped establish the German manufacturing systems engineering even today. (from Wauer, J., Mauersberger, K., Moon, F. C., 2010. Ferdinand Jakob Redtenbacher (1809–1863), in Distinguished Figures in Mechanism and Machine Science, History of Mechanism and Machine Science, Ceccarelli, M. Ed., Springer Netherlands).


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31 Responses to WAP – WARNING! Air Pockets

  1. Phillipa says:

    This is a wonderful model andI’m looking forward to making it. What weight/thickness of card would you recommend?

  2. Ruben says:

    desde españa muchas gracias por sus modelos. son fantasticos

  3. Oscar Joel Quintero Guzman says:

    Muy estimado amigo Giuseppe Civitarese, mi admiración y respeto a su talento, pero sobre todo a su benevolente actitud que muestra al compartir, tan excelso modelo producto de su creatividad. Realmente de corazón, le envío mi gratitud por tan noble actitud. Me encuentro precisamente en una etapa para el desarrollo de modelos de mecanismos para realizar carros alegóricos con movimiento. gracias y espero en lo corto enviarle el producto de mis trabajos. Un saludo cordial desde Jalisco, México.

  4. Dragon Lin says:

    I love this creation very much. I really would like to make it for fun. Thanks for your sharing.

  5. Christine says:

    Absolutely beautiful automata!

    Just one question: how can I open a rar document?

  6. Aryan says:

    I am downscaling it to 25%! I only made the air pockets generator(it is so hard to make this in 25% scale). I will finish it in to two days.

  7. lu laviu says:

    thank you very much for this free model n.n Greetings from Argentina!

  8. Aaron says:

    A4 sized paper is kind of hard to find over here in the U.S.. Will I run into gears not meshing correctly if I scale down to 8.5 x 11″ I’ve done a couple of your other projects but none of them had gears like this. I suppose I could just give it a go, but ink is expensive.

    Your thoughts would be appreciated
    P.s. I think it scales down just under 95% if I remember correctly

    • paperpino says:

      Hi Aaron.
      I am not sure to understand your problem correctly.
      When you resize, you should not adapt to letter page, but you must resize to a percentage of the original. I think 95% could be fine.


  9. Chris Knowlton says:

    I built the WAP and it was very enjoyable. Your part fit is perfect which makes the building fun and the result satisfying. The way you have designed each part is quite amazing. The assemblies that I thought might go together with some dificulty are easy because of the methods you used in creating them. It is a fantastic piece. Thank you.

    Chris Knowlton

  10. Mike Parker says:

    I love this model! The range of movements is amazing, and the colors and details are really well done. I am looking forward to building this. thank you very much for making this available.

  11. Tim Davis says:

    Nice! Now I have WAP sitting on the shelf next to WITS! Thanks for the very nice models!

  12. benhu261hcm says:

    I’m making it !
    So amazing , so hard but i love it
    Thank you very much ^^ ………

  13. Rodrigo García says:

    Hi Mr. Paperpino.
    I’ve only just started in the world of papercaft and have been fascinated with his designs, is a real inspiration to me.
    Maybe one day not too distant to make my own model
    Thanks for sharing your talents.
    Grettins from Mexico city

  14. michael says:

    Hi,I have finished wap it looks great.I had some problems,mine not
    yours,the sun ended up on the opposite side(oops).All in all a great fun build thanks

  15. Nghia Zer says:

    Awesome model! Thanks you very much to sharing it.
    May I translate instruction to Vietnamese (my native language) and repack it in to new PDF file to sharing it in our fanpages 🙂

    • paperpino says:

      Thank you Nghia Zer for your appreciation!
      Yes, of course, you can translate and repack the project. Please, when ready, send it to me the pdf file (it will be the first time I see one of my model in Vietnamese version… 😉

  16. This is the first time I’ve made your models, it is fantastic, thank you very much for sharing it.

  17. michael says:

    Great model I am building it but I am slow(careful)just one question
    several times you say print the back,what does that mean.Any help appreciated

    • paperpino says:

      Hi Michael!
      Just print the back of that page. Some parts are colored on their back, too.
      I mean, the page after the one where it is written “print back” is the back of that page.
      Clear? I hope so…


  18. David says:

    I have to make it, but where are the instructions.

  19. michael42er says:

    A fantastic model and realistic video. I’m looking forward to the build. Very interesting is the inclusion of the variation of the Cartwright mechnism. Thank you Pino for the elaborately designed model with free download.

  20. Pascal says:

    Awesome. Thank you very much for sharing it. i have already done some of your automatas. i will have a lot of pleasure making this one.

  21. maxlrainer says:

    Wow, it’s really amazing. Your most sophisticated model since “Wandring in the sky”. Tank you very much Pino.

  22. Dan says:

    Great model and video! Thank you!

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