British sculptor, Alastair Mackie used the 3D laser cutting capability of Lairdside Laser Engineering Centre’s Prima Laserdyne machine and Camtek’s PEPS SolidCut 5-axis CADCAM software to produce his recent work entitled Bipolar.
The work comprises of a genuine US Marine’s helmet into which has been cut an Islamic style fretwork pattern. The piece was exhibited at the Mark Moore Gallery in Los Angeles in Alastair’s solo show entitled, Sticks and Stones, between 13th October and 11th November, and 6 more pieces will be cut as a limited edition.
Not surprisingly the laser cutting of the item was not a simple engineering project. According to Lairdside Laser Engineering Centre, the whole project required considerable effort from Alastair, a leading CADCAM software company, and Lairdside Laser Engineering Centre.
It is often the case that when an artist attempts to introduce a hi-tech engineering process into his work, what often appears as a relatively simple process becomes problematic, as the bounds of the technology are pushed. The concept was straightforward, take a 3D scan of the helmet, superimpose the fretwork pattern and then cut it. However, the steps leading to the programming of the 3D laser cutting machine are not so straightforward.
A scan of the helmet was simple to procure. However, the overlay of the pattern was by no means simple as Alastair recalled, it took several weeks to find someone who could do this and produce an electronic model of the sculpture. Then, Alastair was able to look at his piece in 3D, but only on a computer screen.
When Lairdside Laser Engineering Centre received the imaging file, it was also able to look at its image. But it was unable to generate the necessary CNC programming code to control the laser cutting machine.
Camtek, suppliers of the PEPS CADCAM software stepped in to help. Camtek worked on the actual computer model of the sculpture to ensure that the computer data was able to be processed by PEPS.
According to Camtek UK, the designer used 3D Studio Max to generate the initial images of the piece. DXF was the CAD format that could be provided from it. The DXF data, however, yielded in excess of 20,000 3D lines, which did not have a sense of 3D orientation and were of little use for generating a 5-axis laser toolpath. What Camtek was really after was a surface model of the component, but were told that this could not be provided from the imaging package. Working with Lairdside, an IGES file was provided, which generated nearly 7,000 wire bodies, forming a 3D facetted mesh representation of the helmet.
Being presented with this kind of data, thousands of unrelated 3D facets, with no sense of connectivity, can be a nightmare for a part-programmer needing to get a job out the door, or for any CADCAM salesman trying to sell his wares for that matter.
But generating usable data proved to be so easy with SolidCut laser, Camtek was able to do so quickly and automatically, by generating 3D solid entities from the triangulated facets and to join them together to create a single contiguous solid model suitable for machining. Applying the toolpath was equally easy. Camtek’s Autocut function generated a complex 5-axis laserpath including lead-in and lead-outs for all of the trims, nearly 750 individual cuts, within seconds.
Once this was done, the PEPS SolidCut system supplied by Camtek to the Lairdside Laser Engineering Centre readily produced the optimised NC code required to drive the machine. The cutting of the helmet was then relatively straightforward. Lairdside Laser Engineering Centre used the automatic 3D fixture design function integrated within PEPS SolidCut Laser to generate a nest of interlocking plates to support the helmet during cutting. SolidCut Laser even nested and profiled these 2D plates for it.
The piece was completed with only hours before Alastair flew to Los Angeles for the exhibition. The sculpture was well received by its Los Angeles audience. Six copies are going to be manufactured as limited editions.