July 2011

A doorknob.  A portrait.  A playful pun.

“Knob Head” was created as an experimental piece whilst working with a Dimension 768 BST 3D printer machine.



I wanted to create an object using the Dimension 768 BST 3D Printer – just to see what it could do.

Looking around my studio for inspiration, I settled on redesigning the doorknob by way of a quick test-subject.  I would replace the wooden ‘knob’ with an original 3D-printed plastic component.

The size of the subject matter was perfect for trying out the Dimension printer without investing much time, money or material.


In my sketchbook, I began playing about with various designs; amorphous Gaudi-esque blobs and complex mathematical models .  I then thought of a head…, then a face… I drew a door-knob which consisted of a 360-degree sweep of a human profile.  I then realised the ensuing pun of creating a door-knob from one’s physiognomy: a “knob-head”.  Most amusing!

In selecting a facial profile to use for the “knob-head”, I tried to depict someone who at the time (late July 2011), was fairly universally regarded as a ‘knob-head’ hence; the Libyan dictator Col. Muammar Gadafi.



1. I acquired a photo of Col. Gadafi in side-profile.  This one sourced via Google Images.

2. Using a 2D vector program, I traced Gadafi’s profile from the photograph (shown above in yellow line).


3. The vector profile of Gadafi was imported into Alias Studio Tools to create the 3D model (above).  A 360 rotated form is easily created.  I hollowed-out the form (to reduce material) and modelled-in details that would allow me to attach the plastic knob to the original brass collar.

Gadafi’s profile is recognisable, helped in part by the hat and characteristic (big) nose…

The ridges that result from the rotated mouth, nose and eyes are a pleasing detail and evoke the grooves of the original lathe-turned wooden door knob.


4. From the Studio Tools model, an .STL data file was generated for translation to the Dimension 3D printer.

5.  The picture above shows two complete 3D prints surrounded by grey ‘support’ material.

The orientation of the parts during 3D printing can lead to variations in build quality.   I printed two – one horizontally one vertically – so that I could analyse which orientation would produce the better quality part.

The grey support material was simply ‘broken-away’ afterwards by hand or pliers.


6. The plastic head is cleaned up and attached to the brass collar using the original grub screw.

Shown above in white ABS plastic with an original brass collar.  The juxtaposition of the materials is pleasing; the brass collar both compliments and elevates the appearance of the translucent ABS, which, on first sighting, is often mistaken by visitors for ceramic or marble.


From above, the facial profile is not apparent and the visual language is still,  undeniably that of a door knob.  Even to the touch, the object feels and functions almost exactly as the original wooden doorknob.

Shown here (above) painted in acrylic to resemble the original wood.

The 3D data could very easily be transferred to manufacture in wood via 4-axis CNC machining …but that’s quite enough for now!