Moving Things with Necks and Springs

The first step of this project in making for me was focusing on the mechanical parts of the puppet. Because this is an area I have less confidence in compared to sculpting, casting, sewing and designing, it requires tackling with the most enthusiasm and momentum. The first prototype I made was inspired by the vertebrae in a spine;

Image courtesy of http://www.spinalhub.com.au

The basic form consists of discs which are held together by muscles and ligaments, making up the spinal column. This works effectively because the tension of the ligaments allows the spine to flex. I decided this was a good place to start in making a very rudimentary version of this; wider plates between the vertebrae of my prototype allow the spine to take on the shape of the neck better, and allow holes to be drilled with hold the 'ligaments' of elastic which keeps the neck mobile. Tensioning these to be stronger on top means the neck sits with a natural upwards curve.

On a small scale, this prototype worked well; it had a lot of organic movement and wiggled naturally. However, when scaled up to full size, it was heavy and unruly, having a tendency to droop to either side, and didn't cope with having the weight (a water bottle) on top of it without being fully held up by the actor:

At this point it was clear that I'd have to take a different approach to making the neck. After some liaising with tutors, I was advised to look into a more spring-based device, and after some loose sketches it became apparent than an 'anglepoise' lamp would become a good base, even if just for the springs. After buying a lamp and toying with the flexibility and movement, it seemed that it may work well for my Dodo's neck with fairly minimal modifications; it bent in a way that one images a swan's neck bending, and with suitable bulking-out this shape would work well for my puppet. Here's how it looks after removing the shade and wiring, and after welding a pole to extend the base of the lamp as a secure point to be later anchored to a plate and a harness. The welding process was a large learning curve, being hot, loud and extremely bright. Luckily, because the lamp's structure is mild steel and not alumium, MIG welding was appropriate for this task.

Image courtesy of migweldhowto.blogspot.com

MIG - 'Metal Inert Gas' - welding uses a handheld nozzle which creates an art of electric between the wire electrode, visible in the diagram above as looking like a pen nib, and the workpiece's metal. The heat from the arc of electricity causes the wire and workpiece to melt, melding the two together in a strong bond. The gas nozzle ensures the work area is shielded, enabling a more precise weld. In order to get a good contact between the two pieces of metal, we rasped the powder coating off the base of the lamp before welding the mild steel rod to it. This has made a strong, solid connection between the two pieces which should make it much easier to attach the lamp onto a solid base through further welding later on.

A pipe-bending spring from the local Wickes marks the start of this base, as the neck shouldn't be rigidly attached to the harness if possible; some movement would be good, allowing the bird to look down to peck at the floor, or up to reach a berry. This will hopefully be made viable by sitting the mild steel rod inside the pipe-bending spring, and then using three or four metal tabs on both the rod and the base, and connecting the two with further springs. With any luck, this will create a sturdy and self-supporting anchor point that still allows flexibility and movement from the actor.

The next big 'moving part' I am tackling is the jaw mechanism. Before making a physical sample, I toyed and discussed a lot of ideas with tutors, friends and Strangeface's Russell Dean, amongst other online presences from puppetry groups. Here's a selection of sketches I came up with, musing different possibilities. It became apparent quite early on that simplicity was key with these moving parts, and as such I strived to develop the mechanism which seemed the most straightforward and easily modified; the PVC pipe spring method, shown as the last illustration here.

My first realisation of this mechanism was through the use of an old section of broom handle, some MDF from the scraps bin and a small piece of PVC tubing that was laying around. I found an excellent tutorial for making this type of spring mechanism on youtube, visible here; 

And so I set about scaling it up. My first test piece was actually slightly oversized, mainly due to interest to see if it would work on such a large scale, and it did - until I over-opened the lower jaw, putting so much strain on the MDF notch that it lifted off the entire section of MDF that was actually holding the lower jaw in place. This prototype is also very heavy, so whilst the movement is great, it's clear that I had to find an alternative material to make the upper and lower jaws out of.

This is the revised, version two prototype of the moving jaw. It works very well, and will need to be anchored somehow to the head via the top jaw. In this sample I have used the end of a broomstick, but for the actual one I would like to put in a metal bracket to attach to the lamp, for security and weight purposes. Also, instead of string, I would like to use a bike cable and brake handle, which will run down the inside of the hollow, rigid reins that will be explained further later on. For practice purposes, string works fine - but it wouldn't hold up to constant wear and would fray and break rather quickly.

The next step for this project is to make a final design for the head of the bird and a detailed scale. The head will be made out of vacuum formed plastic in two halves, which will be bonded together in the middle. Because of this plan, the head will be sculpted in two pieces, either side of a wooden template, so the vacuum formed result will match up perfectly in the middle. To achieve this, I must have very accurate drawings of how the bird will look from the front on, and a good set of measurements and style guides that will dictate how my sculpture should look.