CNC: Detailing The Design

Computerized production can speed up and smooth out a shop’s workflow – but dealing with the computer itself is another matter.
All CNC-based devices allow for entering the dimensions of a job, along with tool placement and speed, at the controlling computer. It’s possible, though, to get job information directly from the source – the installation site – and even deal with some design issues.
CNC-based machines need a tool path; basically, it’s an outline of pieces to be cut and processed. Most of the CNC models accept data set in the .DXF file type originally developed for the AutoCAD® CAD/CAM program – and at least three programs tailor .DXF output for production templates.
Raleigh, N.C.-based ETemplate Systems takes the absolutely virtual approach; all it needs is a photo. The $9,995 ETemplate™ system images from a digital camera and transforms into a .DXF file suitable for CNC work.
ETemplate’s Nick Nichols explains that the process involves placing reusable markers along the angles of the area to be templated, along with other items to show scale. It’s possible to do vertical and horizontal surfaces, scribe a wall, and collect multiple angles, such as bump-outs at a sink base.
The system includes a Casio model calibrated to work with ETemplate’s software. In processing a series of digital images, the program recognizes the corner and scale indicators to produce an electronic template as a .DXF file for use with a CNC machine. Nichols says the software templates are accurate to +/- 1/8”.
For the real feel at real scale, BVH Gregg Inc. of Missouri City, Texas, offers the CMS 8400 Stealth Digitizer. By electronically marking angles right at the workspace, it records data straight to an onsite laptop computer.
The $9,995 Stealth uses a digitizing stylus mounted on what looks like a standard, elbow-style drafting arc. By clamping the arm on a countertop or an optional mobile stand, the arm can pivot 270° in a 7’ radius arch, and work a rectangular area of 10’ X 10’.
The Stealth is attached, via serial port, to a laptop computer supplied by the user. The data from the digitizer is recorded as a .DXF file for use by a CNC machine. (Users can also use BVH Gregg’s JetStream for editing the .DXF file, but the additional software isn’t required.)
Jacksonville, Fla.-based Outline Technologies Inc., meanwhile, doesn’t eliminate the physical template at all. With a working area of 12’ X 5’, the company’s super-sized digitizing tablet allows for speedy 1:1 recording to a .DXF file.
The $17,950 system, which includes CADopia LLC’s IntelliCAD ™ software, may seem an odd combination of old and new methods. Outline President Richard Still, however, notes that it combines the accuracy of physical templates with the ability to save them electronically.
The large digitizer allows for templates up to 2” thick; data can be entered in a minute or less for most templates. For going on the road, Outline offers a 12’ X 4’ truck-mounted version.
Sometimes, though, it’s not a matter of data; it’s how a job would look with certain designs and stone varieties. While it’s possible to use off-the-shelf computer programs to cobble together a solution, Accurate Image Marketing in Bloomington, Ind., works to provide the perfect match.
Accurate Image’s software creates dead-on replication of color and texture; with construction materials, it’s been used with general masonry products, with the ability to match stone as well. Company president Vince Whitted notes that digital photography and digital measurement of actual products are used to ensure visual harmony with computer images.
The custom product is often used for cataloging and displaying products from suppliers, but Whitted notes that Accurate Image software could also be used in design. “It provides the ability to look at products interchangeably on a building,” he says.

This article first appeared in the September 2002 print edition of Stone Business. ©2002 Western Business Media Inc.