Video: Making a 3D Print

In this video, a replica (a 3D print) of a vertebra from the Puijila darwini fossil is being made. The technician is Andrew Trowbridge, of Arius3D.

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What's Happening in the Video

The well of the 3D printer is full of a white, cornstarch-based powder. On each pass, the printer heads lay down a thin layer of a chemical solution on the powder. The solution binds the powder and a solid is formed.

After each pass of the printer heads, the upper surface of the newly formed solid layer is covered again with the powder. This provides a new supply of powder to bind to the solid layer underneath. The three-dimensional shape is gradually built up by layers.

The pattern that the printer heads follow is directed by 3D image data. The data were gathered previously from the original fossil specimen by a 3D laser scanner.

The data describe the size, shape and surface texture of the fossil. The fossil's colour is also part of the data, and the printer effects that too, although the colour is not visible at this stage. The replica bones are thus an exact reproduction of the original bones.

Arius3D Technical Director Andrew Trowbridge removes the 3D-printed bones from the powder and gently cleans extra powder off with a brush. The replica is still quite fragile at this stage. Inside a collection box, he uses an airbrush to clean more thoroughly.

In the next step, Trowbridge applies a liquid chemical over the entire surface of the replica bone. The liquid causes chemical reactions that harden the replica and bring out the colour of the replica bone.

Two copies of each bone were 3D-printed. Two 3D prints of the entire skeleton were later assembled and mounted.