Friday, 16 November 2012

B & S armature construction- part 4

With my mild steel brackets completed (including a spare pair just in case), I was ready to begin making the ‘bones’ of my puppet- comprising brass beads soldered onto lengths of brass rod. Unfortunately, I was unable to find 3mm rod, and so bought the nearest size I could (3.08mm) and used the grinder to narrow the ends just enough to fit snugly inside the beads. As you can see above, a spare screw box makes a fantastic storage box for armature components!

With my Gollum designs printed actual size, I was able to determine the exact lengths of brass rod I needed, and compiled a list of the parts I had to cut. With this step complete, I was able to set up my soldering equipment is my garage, which is well ventilated.

The items were placed on a workbench, atop a spare floor tile, which would absorb the heat from the blowtorch. The brass rod sections were positioned in a mini helping hands vice grip, so to keep everything steady.

The brass that was to be soldered was cleaned with a piece of wire wool, and coated liberally in flux to aid the soldering process.

The metal was heated at first so that the solder would melt on touch and flow into the gaps around the beads to seal them. Solder was placed quickly under the flame and allowed to drip onto the rod/bead seam, before the flame was turned off and the component was allowed to cool. Flux was brushed on numerous times during the process to further aid the solder bonding to the brass.

With beads soldered either end, my first brass component (Gollum’s lower leg) was complete. The piece fitted perfectly in the steel brackets, holding its position when they were tightened. The same process as shown above was then repeated to create the full set of ‘bone’ parts I required.

The legs, arms and spine were then assembled and tested by simply playing with the joints. I found several that were weak and broke, and so I fixed these before carrying on. It is imperative that weak points are identified and corrected at this stage, before the armature is permanently built upon with foam and latex.

Soldering brass rod to the hip and chest plates was trickier, for the rods had the natural tendency to roll away. Crocodile clips were used to grip them in place whilst solder was applied in the same manner as before. The hip plate also features an M3 hex nut on the reverse side for rigging. Heating the back of this plate, with rods already attached, was difficult- the extra heat broke the existing solder, and I had to reattach them.

To finish the armature, sections of square K & S tubing were attached to the neck and forearms in anticipation of the hands and head being added. The feet were also fitted with hex nuts, with a hole then drilled through the sole, for tie downs to be inserted.

I actually spent quite a while testing each pair of brackets and grading them for their strength, as some were weaker than others. The armature needed to be tuned, such that it was tightest at the base and weakest on the extremities, in order to effectively support its own weight. The better, tighter brackets therefore were used for the feet and legs.

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