A Real Leg Up

Hi readers! Last time I posted to the blog I was in the trenches of raptor leg building. I’m happy to say that we have finally locked down a solid leg structure. Since each dancer controlling each raptor is a slightly different size, not to mention the ridiculous range of motion one gets from hip joints two feet away from actual human hips, the legs are completely adjustable across 3 dimensions. The insides look like this:

view of raptor legs

Raptor leg prototype showing interior aluminum bones and joints.

A breakdown of the components reveals rattan loops, threaded metal rods, two types of joints, and various nuts and bolts. The ball/socket joint connects to the hip while hinge joints with adjustable angle measures manage the knee and ankle.

showing the parts of the raptor leg

Leg pieces. Threaded rod “bones,” rod end joints, and rattan muscle structure, and 3D printed clamps for the threaded rod.

Most of these pieces are generic, but the clamps are not and deserve a spotlight (below). Since it was taking us so long to cut custom clamps to hold the rods in place, J.E. had the idea to turn to 3D printing instead. It’s worked great!

detail of 3D printed parts

Detail of 3D printed threaded rod clamps.

Once the skeleton is in place, ABS rod is weaved around the 2D shape to bring it into the 3rd dimension. This idea was in part inspired by visiting artist Mikela Cowan, who showed us the reed waving technique used to make Chinese dancing lions.

interior of Chinese lion head

Chinese lion heads woven like baskets with thin strips of bamboo.

Once weaved and covered with Caitlin’s wire surface treatment, the raptor is ready to walk on its own! We still have some adjusting to do with the leg and foot (thanks Karen!), but the raptor has certainly gotten a leg up these last few weeks.

full view of raptor and legs

Final leg assembly before paint,

Now just 4 legs more to go!

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