A corporate logo,
in three dimensions,
for a trade show

... supply a 1200mm (4 ft) diameter sphere, and a suitable case, for air shipment interstate. The obvious answer to the weight factor was to use polystyrene; but polystyrene has its own peculiarities requiring special treatment, and a unique approach to create this one-off sphere.

A vertical lathe bed was made and large pulleys fashioned, one for the base of the dowell spindle, and one for the drill press (that's right) that provided the spin.

The sphere was laid up in 100mm thick laminations with the joins following the lines of lattitude so the adhesive didn't cause too much interuption when the thing was turning.

With the lathe turning at about 120 rpm the shape was roughed in with a wire brush, the form then filled with a plaster mix and sanded.

The bed of the lathe was rotated 90 degrees so the shaft was horizontal. Two coats of epoxy resin and a single layer of light fibre-glass matt, more sanding, and a couple of coats of polyester resin. More sanding.

The sphere was painted, lines applied and checked before being boxed and despatched.

An attractive finished product, deceptively simple.

- more carving - dinosaur skeleton

- & more carving - shipwreck