CS 184, 5/11/2009
My Own Use of
Computer Graphics
Carlo H. Séquin
University of California, Berkeley

Brent Collins
“Hyperbolic Hexagon II”

Brent Collins: Stacked Saddles

“Hyperbolic Hexagon” by B. Collins
 6 saddles in a ring
 6 holes passing through symmetry plane at ±45º

= “wound up” 6-story
Scherk tower
 Discussion: What if …
 we added more stories ?
 or introduced a twist before closing the ring ?

Scherk’s 2nd Minimal Surface
Normal
“biped” saddles
“Scherk Tower”
Generalization to higher-order saddles
(monkey saddle)

Closing the Loop straight or twisted
“Scherk Tower” “Scherk-Collins Toroids”

Sculpture Generator 1, GUI

Slices through Minimal Trefoil
50% 30% 23% 10%
45% 27% 20% 5%
35% 25% 15% 2%

Profiled Slice through Heptoroid
 One thick slice thru sculpture, from which Brent can cut boards and assemble a rough shape.
 Traces represent: top and bottom, as well as cuts at 1/4, 1/2, 3/4 of one board.

Emergence of the Heptoroid (1)
Assembly of the precut boards

Emergence of the Heptoroid (2)
Forming a continuous smooth edge

Emergence of the Heptoroid (3)
Smoothing the whole surface

The Finished
Heptoroid
 at Fermi Lab
Art Gallery (1998).

Various “Scherk-Collins” Sculptures

Rapid Prototyping with FDM

A Look Into the FDM Machine
2 NOZZLES
Galapagos 6 sculpture in progress

Extending the Paradigm: Totem 3
Bronze Investment Cast

Snowsculpting Championships 2003
The Team: “Whirled White Web”
(C. S équin, S. Wagon, D. Schwalbe, B. Collins, S. Reinmuth)

Day 1
Removing lots of snow …

Day 2: Making a Torus

Day 3, pm: Carving Flanges, Holes

Day 4: Geometry Refinement
“Devil’s Toothbrush”

Day 5, am: Surface Refinement

12:40 pm -- 42 ° F

12:41 pm -- 42 ° F

“WWW” Wins Silver Medal

Brent Collins’
Pax Mundi
1997: wood, 30”diam.
2006: Commission from
H&R Block, Kansas City to make a 70”diameter version in bronze.
My task: to define the master geometry.
CAD tools played important role.

Emulation; Define Master Pattern
 Master to make a mold from.
Alignment tab
 Use 4 copies.

Design of Two-Part Master
 Alignment tabs for easy assembly

Subdivide into Two Master Segments

Joe Valasek’s CNC Milling Machine
 Styrofoam milling machine

Machined Master Pattern #2

(Cut) Master  Silicone Rubber Mold

Mold  Several (4) Wax Copies

Spruing the Wax Parts for Casting

Ceramic Slurry Shell Around Wax Part

Shell Ready for Casting

Casting with Liquid Bronze

The Freed Bronze Cast

Assembling the Segments

The “Growing” Ribbon

H&R Block Building
Front Door of the ...

The Final Destination

Steve Reinmuth Tightening the Bolts

Brent Collins Polishing Our Baby

Thanks to Steve Reinmuth ...
 for creating the beautiful patinas,
 for the fabrication photographs.

Questions ?