Thursday, 30 April 2015

Eagle Template

The animation I took from shots I took of an eagle flying recently - stripped of color and simply presented in "find edge" mode. This made it look like an animation of a series of drawings.

I have rescued a couple of mature grape vines and a metal structure to support them - the structure is quite large and I wondered about building a sculpture to go with the structure.  My initial thought was a scale profile of a Wedge-tail Eagle.

After watching the animation for a while, I started to wonder whether a better idea might be to build a metal 3D representation (using tin).  This would not be an attempt to create a lifelike version, Rather the tin structure would present common profiles as it is caught by the wind.  These are massive birds (the size of a small car) - so integrating a full scale version into the structure will present a number of challenges.

The first task was to create a small template and to create a first model to see whether the approach might be attractive.  I sized, printed and cut out the template of 3 shapes (note with shape 3, the wings are not cut out - they are in the template to show position in the final structure).  The body (3) and wing supports (2) were glued together using the slots A and B.  The wing/tail structure (3) was bent into shape - to match the shape of the wing support and glued (I used superglue for this element).  I then gave the structure a spray of an enamel paint to make it water proof and hung it on a short piece of thin wire.

This took a couple of minutes - and as a prototype I didnt take much care in execution - putting the template onto fairly thick cardboard.  If I was doing this again, I would use thick cardboard for the wing structure (1) but lighter fine/rigid card for the wing (2) and body (3).

The little model presents a nice profile - with a slight breeze all the shapes in the animation are realized.  Using light-rigid card would have been a big improvement.

At this size, 4 inches wingspan, it might happily be adapted into a mobile or, with the feather pattern printed onto card, might be an easy way of recreating a more lifelike representation.  I will explore both of these.  At double that size, 8 inch wingspan, the shapes might be printed onto light plywood and given significantly more detail - perhaps including overlapping feathers on the wing.

A real eagle more than 20 times this size - with a wingspan of 90 inches.  The small model demonstrates some of the problems scaling it up - especially around the rigidity of the structure.

So the first move might be to build a metal version at 6 times the size - with a wingspan of 20 inches. At this scale I can start adding body elements and start incorporating far greater detail. Like a plywood model, individual feather details might be incorporated in an overlapping pattern.

While a 20 inch model might be freestanding and designed to be caught by the wind, the 4 inch model shows that it would be unnecessary for the final 90 inch model to be caught by the wind, because, if placed in a fixed position above grape structure, the changing profile will be visible as you move around inside and out of the structure.

Peter Quinton
May 2015

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