Golden Era Productions, Gilman Hot Springs, CA, produces religious film, video, television, and events. These productions require considerable numbers of sets and props which must be produced to high levels of detail and accuracy, primarily from foam and wood.
In the past Golden Era used a 2.5D router with 9 inches of Z-axis travel which limited the depth and complexity of the parts that could be created.
Golden Era upgraded to Delcam’s PowerMILL 5-axis computer numerical control CNC programming software and a 5-axis CNC router from DMS. The new software and router make it possible to produce pieces as big as 10 feet by 5 feet by 48 inches in a single setup including complex, highly detailed 3D surfaces.
“With PowerMILL we are able to make things that in the past we would have had to carve by hand or in a multitude of laborious steps, which added days to an otherwise simple program that now takes only hours with PowerMILL,” said Ron Sommerville, Sets Chief for Golden Era Productions.
“This capability has helped our creative process take a huge leap forward. Now the challenge is to see how creative we can be, as the software can literally do anything we can imagine, and with speed and quality.” As an added bonus, complex tool paths are made user-friendly and simple to do, which makes programming a breeze.”
The focal point of Golden Era Productions is the 80,000-square-foot film studio. The main sound stage rises more than three stories, with an interior the size of two football fields. Final production of the religious audiovisual properties filmed at Golden Era Productions is accomplished in the cutting-edge post-production facilities, which include 21 digital editing bays that are used to create any required digital effects.
Golden Era’s special effects department harnesses more than 500 computers. Religious film and video musical scores are produced and mixed in-house in Golden Era’s recording studios.
Golden Era Productions has a continual need for sets and props for its films and events. For example, the organization recently produced a film shot in the studio of an artist who is working on a partially finished sculpture. The artist also has a number of finished sculptures in the studio.
The partially finished sculpture could not be produced on the previous 2.5D router because the router was limited to contouring a single workplane to a depth of 9 inches. Hand carving would have taken a considerable amount of time and would not have provided the desired level of detail and accuracy. Golden Era could have subcontracted the job to a local machining operation but this would have been expensive and involved significant delays.
Sommerville had previously undertaken a search for computer software and a machine that would let Golden Era produce a full range of contoured 3D parts for use as props and in sets without the limitations of the previous machine.
He selected a DMS 5-axis CNC router because of its ability to produce large wood and foam parts at a price that is much lower than a conventional machining center with the same capabilities. The machine requires 5-axis milling CNC programs that can produce 3D objects that are machined on all sides from a single setup.
“DMS recommended PowerMILL because it is very easy to learn and use yet provides the ability to take full advantage of the potential of 5-axis machining,” Sommerville said. “PowerMILL makes it possible to easily establish workplanes around the part. Once a workplane has been established, programming is carried out in a manner that is easy to understand for anyone that is familiar with conventional 2.D programming.”
In the case of the sculpture, Sommerville began by importing a 3D computer aided design (CAD) model of the sculpture into PowerMILL. He created a workplane that coincided with the bottom of the workpiece.
This workplane was used for machining the top of the part. Then he established four more workplanes at 90 degree angles of rotation around the workpiece. He established one more workplane specially to machine the arm of the sculpture which was difficult to reach from the other workplanes.
He divided the part model into five areas, each of them consisting of a section that could be effectively machined from the vantage point of one of the workplanes.
Next Sommerville used PowerMILL’s model area clearance roughing milling strategy to efficiently remove the bulk of the material from the workpiece by maintaining constant cutter loads and minimizing sudden changes in cutting motion.
He set up roughing toolpaths for each of the workplanes simply by selecting the workplane and the desired strategy. The PowerMILL software then automatically generated the toolpath.
To finish the part, Sommerville used the 3D offset finishing strategy. 3D offset machining delivers an excellent surface finish because the step-over is varied to give a constant cusp height, both on steep surfaces and shallow contoured areas.
Spiral offset finishing prevents witness marks, reduces machining time and improves tool life since the tool stays in constant contact with the model in one smooth spiral motion while giving an excellent surface finish. Again, all that was required to set up the finishing toolpath was to select the workplane and finishing strategy.
Sommerville then issued the command to generate the toolpaths and G-Code needed to machine the part on the DMS router.
“PowerMILL’s collision avoidance feature automatically avoids hitting the workpiece while traversing,” Sommerville said. “In this case, the main obstacle was the arm.”
PowerMILL’s collision avoidance tools automatically tilt the cutter away from obstacles by a specified clearance. Once clear of the obstacle, the tool returns to the original cutting angle.”
Sommerville simulated and verified the g-code program inside PowerMILL including viewing each machining operation within the entire machining environment and the finished sculpture after machining. The simulation showed the CNC program produced the sculpture perfectly. In some cases, the final geometry does not exactly match the design intent so Sommerville goes back to initial part geometry, makes changes and updates the g-code.
The sculpture is a typical example of the wide range of 2D and 3D parts produced by Golden Era Productions. Golden Era Productions has a number of different software programs that they use in different stages of a design or for different types of jobs.
Typically 3D designs are created in 3D Studio Max, if final tweaks need to be produced for modeling they can then import the design to other programs (like Delcam’s artistic software for design and manufacturing ArtCAM) the design elements are then exported to be produced.
“ArtCAM has powerful features for creating text and 2D and 3D designs and can also generate toolpaths for the DMS CNC router which can be very confident for doing 2D and 3D parts," Sommerville says. "When we started getting into more complex parts we felt we needed something that required 5-axis machining. With our software expertise we have the ability to design anything."
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