Movable neck of a 6m mountain lion!

Hey guys
We are currently making a 6m long puma! (Foto 01)
The whole puma will be made of styrofoam, covered with fake fur.
The head of the puma should move!
He shall lift and lower, look left and right, and his mouth shall open and close.
All these movements are to be carried out mechanically by people in the Puma.
At the moment I am working on a 1:5 model. (Foto 02)
The mechanical parts there are designed and move effortlessly. (Foto 03 and Movie link
The head and neck are moved by hand, the jaw is opened with the foot via a pedal and closed again with a spring.
Now I am looking for a solution for the moving part of the body in the area of the neck.
I tried it with an hollowed out foam part. (Foto 04)
But this solution does not work, the foam makes the neck very stiff and immobile.
I have found that foam is compressible but not stretchable!
Does anyone have a good idea, an input for us, how we can make the neck movable?
Unfortunately, we do not have the possibility to make the neck in this size from Foam Latex!

We are happy to see any proposal!

Thank you very much in advance!!
Best wishes

Foto 01

Foto 02

Foto 03

Foto 04


  • edited August 2019

    Awesome project, and great looking puma!

    For the neck, I would use rings of foam.  You can cover the outside with a 2 way stretch material like "Power Mesh" to prevent the top fur layer from sagging down between the foam rings.

    Picture 5-6 foam rings, linked together on the side/top with a bit of foam between them.  You can even alternate the location of the foam that connects the rings so on the first pair it could connect the 2 sides, then on the next pair the 2 top/bottom, etc to allow for easier compression for left/right and up/down over the length of the neck.

    Here's a quick image I made that illustrates this type of foam linkage.

    You can use different density foam for the connecters (shown in green) as needed.  Softer will allow for more movement, and firmer will allow for more support.  If more support or durability is needed you can have top/bottom and left/right connectors on all rights, or even use full rings of a lower density foam.

    It could work as a simpler version of the neck used for the Raptors in Jurassic Park.

    We have a photo of it on our blog post here:

    Hope that helps!

  • Hey Chris
    Thank you very much for your quick help!!
    I will try it in my little model and give you feedback how it works!! 
  • Hello Chris

    Here is a little feedback about our 6m Puma and yes, we have a new question/challenge/problem!!
    As you can see, the puma is alreadyvery far advanced.

    Body and head are carved.

    The neck is built according to your recommendation. In model size it works perfect!!!!! We think it works also on the big puma.

    Now we are attaching the fur.

    And I`m working on the tail and the mechanics for it.
    And the mechanics of the tail is the point on which I have a question/challenge/problem.
    My construction is very unstable!
    I have a 2-way mechanism at the front and a 4-way mechanism at the back of the tail.

    The front part is stabilized with a 3mm polyamide plate.

    At the back at the moment I use a 6mm speedometer cable, You can see it 1 photo above.

    The speedometer cable is very, very unstable so I covered it with a small tube of aluminium between each slice.

    But this is not enough, here I need your input please!
    So I hope you have time and muse to help us once again with a tip.

    The cables are 2mm stainless steel cable.

    In order to limit and control the movements, we pushed thin aluminium tubes over the cables. The slices are out of hard plywood, thickened with a ring out of a PVC foam plate.

    The tail it self is 2.50m long and out of 20mm soft foam covered with a very elastic and slippery spandex fabric. On top is planed the same fur as we use for the rest of the puma. For the movable parts of the puma, we produced elastic fur (fur transfer) as explaned in a video tutorial of Stan Winston School!

    Do you need more information?

    Thank you very much in advance!!

    And kind regards!!


  • Awesome progress Andreas!

    Can you describe the issue you are having with the speedometer cable?  Is it too flexible?

  • Thank you very much!!
    Yes the speedometer cable is much too flexible!
    I changed today the whole tail.
    The up and down part is now much longer and at the end I will put a polystyrol tail end.
    The part with four cables I have removed.
    It‘s frustrating but the time is over, we have to finish as soon as possible!
    But thank you again for your feedback!
    The photos of the finished puma I will send later this month!

  • One option would be to put some type of flexible tubing around the cable to strengthen it a bit, and also make sure plenty of tension is on all the cables to provide some resistance and keep "slop" out of the system.

    Best of luck, and awesome work!  

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