Bellows Design – Problems and Solution.

Sat, 19 Mar 2016

Next step in the bird box project. Bellows and crank. Turn the handle to pump the bellows. This is similar to the type three model I made before but the guide rails will keep the moving plate horizontal as it moves. There’s a problem though.

As the bellows move back and forth the plates twist in relationship with each other.


This is the net for a section of the current bellows design.

My thought was that if I flip every other row side to side, the rotation in the end plates should be canceled out.

Here’s the new layout.

It takes a little long to score the bellows but the end result works perfectly. No rotation at all!


Here are the two test bellows side by side. Next step – connecting up the crank.

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Comments (3)

  • frankenpaper March 20, 2016 at 1:13 am

    I could never figure out why

    I could never figure out why it would twist! Your solution is very clever. Thank you for thinking of this!

  • maxlrainer March 20, 2016 at 10:42 am

    Great idea.
    I encountered the

    Great idea.

    I encountered the problem with the twisting bellows during building the "Crank Bellows" (or "Bellows Pipe Box") last year. The box works quite well, but the twisting bellows touch the inside surface of the box and disable a smooth movement.

    Your new design will solve this problem. Clever thought!

  • JohnW March 25, 2016 at 5:27 pm

    Kind of like turning the

    Kind of like turning the front wheels of a car toward the direction the back wheels are sliding during icy road conditions, right? It forces the front of the car to travel in a strait line. If this doesn't make sense it's because I'm dealing with touch of man flu.

    Take Care,


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