Skeletal Wings

Time taken: 24 hours
Materials: Baby backpack with aluminium frame, 12mm aluminium strip (4m), 20mm x 4mm bolts (about 40), 10mm dowelling (30cm long), 10mm right-angle PVC bathroom moulding, 50mm aluminium carabiners (18), 3mm nylon cord (4m),  12mm PVC conduit pipe (1.5m), 10mm split rings (32), 10 large cans of expanding foam, masking tape (6 rolls), tissue paper (about 1/4 ream), wallpaper glue, 2 x empty 2L plastic milk bottles, cheesecloth fabric (about 1m), small hooks and eyes (20 or so), hot glue, furniture stain (walnut), paint (white, cream, red, blue, violet), small amount of 20mm EVA foam.
Tools: drill and drill bits for metal (4mm), pliers, hacksaw with metal-cutting blade, craft knife, paintbrushes.
Techniques: Fabrication, carving, paper mache, painting.
Difficulty level: This was a long and difficult job that involved a mix of simple techniques (paper mache), and tough ones (engineering).

Here are the pictures I used for reference:

ref pic ref 2

As you can see, Death’s wings are *huge*, therefore being lightweight and comfortable was really important if I was going to wear them for any length of time.  This is why I chose to use a baby backpack with padded shoulder and waist straps and an aluminium frame rather than the usual strap harness arrangement that often goes with wings.  I bought a second hand one for cheap on TradeMe, and immediately cannibalised it by cutting off the pouch section and shortening the aluminium frame with a hacksaw till it sat flush with my back.  I left the straps on (it also has a little strap that goes across the chest), and then sewed the covering back on.  I ended up with a square, cloth covered aluminium frame that I could strap to my back – perfect!  Sadly I didn’t think to photograph this part of the process.

The other consideration for the wings was that because of their size, they would need to come apart for transport, and I wanted them to be able to open.  This was probably the part that gave me the most headaches, and eventually I settled on making the ‘elbow’ parts separately from the ‘finger’ parts, with each finger clipping onto a rack at the top with carabiners.  The wings would open using a lever at the top that was operated with a string that fed down through a conduit pipe inside the elbow bits to the wearer’s hand.

How does one even start making lightweight, come-apartable, opening wings?  Like this:

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Everything I make starts life in my quad book, where I use the little squares to estimate measurements.  Once I had the various dimensions sorted, I started making the skeleton that goes inside my skeletal wings.  The bones themselves would be made from expanding foam to keep them lightweight, but expanding foam is inherently not that strong, so they needed internal support.  For the fingers, I used right angled PVC bathroom moulding, bolted together into the eventual shape:

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For the elbow sections that would have to support the weight of all the fingers and the stress of opening, I used 12mm aluminium strip.  I also used this for the rack at the top, and for the opening lever on the outside finger.

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In the second picture above, you can see the holes drilled into the aluminium racks where the finger bones would clip on. Each finger bone would have 2 carabiners attached (using split rings threaded through holes in the PVC skeleton) to keep them free moving), which would clip into the holes in the rack. The outside fingers, which needed to be stable in their movement, had the carabiners in fixed position, and would clip onto the wooden dowelling that forms the spreader for the rack.

Each rack was then bolted onto the top of the elbow skeleton.  The elbow skeleton itself was formed from 12mm aluminium strip, and each ‘arm’ has 6 strips inside it. bolted together under tension and then bolted to the backpack frame.  I didn’t think to photograph the bare skeleton, but in the picture below you can see that the part supporting the finger racks consists of four strips, two of them angled to form a brace against the weight.

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I should also note that once the bolts were in place, I dabbed hot glue on each of them to prevent the nuts working loose once the expanding foam had been sprayed on.  There is flex in the wings and I didn’t want a bolt coming undone and collapsing the whole thing after a few wears.  You can also see the bent strip of aluminium I used to form a guide for the loose-hanging wings so that when they opened they would track reasonably straight.  The strip is attached to the outside finger and goes through holes in each subsequent one, and it prevents the wings from flopping around too much.

Once I had the basic skeleton formed, it was time to break out the expanding foam.  The technique I intended to use is the one described in detail by Kamui on her fantastic website.  First spray, wait till it’s dry (about 48 hours) then carve.  Because they were so large, these had to be sprayed on one side first, then turned over when dry to do the other side.  Also, I found that using plastic wrap on my table and a tarp underneath saved me a lot of cleaning up mess afterwards.

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And the same with the elbow parts.  In the left picture below you can see where the frames are bolted to the backpack, and also where the piece of conduit pipe is laid through the middle of the elbow bits and emerges at the bottom.  On the right you can see the wings clipped on to the final carved shapes.  It took a bit of working out the curve of the aluminium stabiliser strip.

 

It was at this point that I began to realise that the conduit-and-lever mechanism was not going to work as well as I’d hoped.  The amount of friction created by the number of angles the cord had to go around (a sharp one at the top, a long curve within the elbow, and another sharp one where the cord emerges from the pipe) was greater than anticipated.  Also, the lever at the top was necessarily short to fit with the proportions of the whole wing.  In combination, this meant that the force required to open the wings was more than could easily be achieved without overstressing the support structures for the elbow.  Also, Death has giant skeletal fingers and a huge scythe to carry, and he’d basically need an extra hand to open the wings.  So I scrapped the idea of having them open, but since so much work had already been done I left the mechanisms intact. There’s a possibility that I’ll come up with a better plan in the future.  C’est la vie.

The other expanding foam part to make was the knuckles at the top, that cover the racks and levers.  These were made using 2L plastic milk bottles cut to shape, and covered in expanding foam then carved to lumpiness.10

I actually ended up carving off most of the foam, as the milk bottles made quite a good basic shape anyway. I got the right shape for the bottoms by sitting them in place on the set up wings, and carving around the bottom to make sure they’d sit right.  Traps for young players – make sure you mark all your fingers and other parts ‘left’ or ‘right’, because carving is not exact and they’ll fit better on the side they were carved on.

Then I got busy with the rest of Kamui’s technique.  Seriously, read her page, it’ll help a lot with understanding how to work with expanding foam.  The short version is to use masking tape to provide a sticky substrate, then tissue and wallpaper glue paper mache till smooth, then it’s ready to paint.

I did all of the bone parts of the costume at the same time, using a technique I learned at a Weta workshop on weathering, specifically designed to make things look like bone.  You cover everything in as smooth a coat as you can of white acrylic, then when that’s dry you use walnut-coloured furniture stain – paint it on, then wipe it off straight away.  this will turn the white into an ivory colour, while darker bits settle in the hollows and it really does look amazingly like bone.

And then, because the ref pics show that the wing bones have tinges of violet in them, I went over the whole thing with a thick wash of violet acrylic, again wiping it off before it could dry.  The result – violet bones!

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After that, the only thing left was to make the webs that the ref pics show between the wings.  I did this using cheesecloth cut into webby shaped bits.  They are glued on one side to the wing, and on the other they have a hook and eye with the hook on the cheesecloth and the eye glued to the wing with hot glue.  This is again because they have to come apart for transport.

I also wanted to have the wings spread a little more, so I made small spacers out of 20mm EVA foam to go between the tops of each finger, and painted them to match the rest of the bones.  I added some cheesecloth at the top of the fingers to hide all the attachment mechanisms, then painted all of the webs and cloth parts in a sort of cream/red/pinkish fleshy gradation, as per the ref pics.

The final result!

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I’m pretty happy with the way these have turned out.  If I were to do it again I’d use more aluminium strips in the elbow so they flex less, and come up with a better mechanism for opening, possibly pneumatic.  Still, for a first go I’m pretty pleased.