Case Study

3D Engraved Chandeliers - Adirondack Studios

For over 30 years Adirondack Studios has helped to design and build themed environments for theatres, exhibit halls, ballrooms, restaurants, malls and casinos.

Having installed ArtCAM to program their CNC machines, the company was contracted by Mohegan Sun Casino at Pocono Downs (Pennsylvania) to produce 5 bowl-type chandeliers as part of a $208 million renovation that dramatically transformed them into the area’s leading entertainment complex.

ArtCAM’s unique ability to create 3D relief directly from a bitmap image and its automatic weave generator helped Adirondack Studios build these chandeliers with a design that included with flying grouse and bird’s nests arrayed in 3D around the exterior.

 

Adirondack Chandelier

Making the chandeliers

Adirondack Studios designers began the construction of the chandeliers by building a 3D AutoCAD model of the chandelier. An STL file of a 60 degree bowl segment was built using an AutoCAD model. Gregory imported the file into ArtCAM, scaled the model and then generated a CNC program to machine a positive shape in a low density Sign Foam slab on the CNC router. This positive then was used by a subcontractor to vacuum form the Tyvek plastic bowl segments. Adirondack Studios then back painted the bowl segments to look like alabaster.

The Adirondack Studios art department provided gray-scale artwork of the grouses that was then used to build a positive mold. Bob Gregory (Senior Router Operator) began by importing the grey scale model using ArtCAM’s Open Existing Model command to both position and specifying the grouse height. He used additional ArtCAM tools to create a machinable relief and built vector boundaries around the grouse and mold perimeter defining machining zones. He used the Create Relief from Image, Create Vector Boundary from Relief, and Create Polyline tools.

A close-up view of the grouse that adorn the chandelier

Then using these vectors Gregory defined the rough clear areas. He first used ArtCAM’s Machine Relief tool to clear out the entire model area using a 3/8” end mill with a 0.15” inch allowance with the outer profile vector selected as a boundary. This toolpath was used to remove bulk material rapidly leaving a flat bottom and a terraced model. He previously had used the Create Polyline tool to draw the defining vector just outside the edge of the visible grouse. This vector and the mold perimeter vector were used to define the mold machine zone surrounding the grouse without touching the grouse. Next he used the Machine Relief tool with a ¼” end mill with a zero allowance tool path around the grouse leaving a very flat base. Using the same grouse perimeter vector he built a relief machining zone for the grouse. Again using the Machine Relief tool he built tool paths to machine the grouse with a ¼” ball nose mill. The Rest Machine tool was used to identify areas and create rest machine vectors for areas uncut by the ¼” ball nose mill operation. An 1/8” ball nose tool was used for the rest machine tool path operation. Gregory machined a full scale model of the grouse from medium density fiberboard (MDF). Adirondack Studios’ casting department used the model to make a mold and cast the grouse using black tinted silicone rubber casting fluid, giving the grouse a wrought iron look.

The next step was to create a bird’s nest pattern and weave it around the circumference of the bowl. Gregory began by creating vector-based artwork that defined the profile of the bird’s nest strand using AutoCAD software. Then he imported the artwork into ArtCAM and using the Weave Generator tool generated a precise 3D relief of the bird’s nest. The Weave Generator allowed him to defined the dive and overlap values that determine how the strands cross each other for a more natural look. “Birds do not use a CNC machine to build their nests so it took considerable effort to get the correct look,” Gregory said.

Gregory generated a CNC program to cut the bird’s nest negative shape into MDF. It took only 15 minutes to create the program for machining the bird’s nest. Gregory estimates that it would have taken at least 4 hours with the software that he used in the past and with marginal results. The mold was used to cast the bird’s nest from the same silicon rubber casting fluid used for the grouse. Both the grouses and the bird’s nest were glued to the bowl of the chandelier.

Change in software helps improve performance

While Adirondack Studios is best known for showpiece creations, 80% of the pieces produced by the company’s CNC machine are actually 2D shapes that are used for interior framing. “The software that we used in the past for CNC programming worked fine for routine jobs but many of the projects that we get involved in are far out of the ordinary,” said Bob Gregory, Senior Router Operator for Adirondack Studios, Argyle, New York.