Resources:
Galil Motion Control, www.galilmc.com

Galil DMC-21x3 motion controller, www.galilmc.com/products/dmc-21x3.php

The Artesà machine in action, as well as video of a manual engraving by artisan for comparison, www.artesa-nc.com/ENG/videos.php

A machine that mimics the craftsmanship of hand engraving uses a four-axis motion controller for precision movements.

Artesà, a company in Barcelona, Spain, developed an engraving machine which employs four stepping motors driven by a DMC-2143 four-axis Ethernet motion controller from Galil Motion Control, Rocklin, Calif. Artesà’s goal was to build a machine that could replicate hand engraving. And the tough part about mimicking hand-engraving work is that artisans perform a downward and upward movement with the chisel for each cut. Artesà’s machine synthesizes this action via a curvilinear or open polygonal trajectory in the vertical plane using nonrotating cutting tools.

The engraver consists of a table with a bed frame firmly holding the workpiece. A spindle-mounted engraving-tool head which includes a laser pointer and three carbide inserts with 35, 90, and 135° corner cutting edges is suspended above the table.

The motion controller controls the critical PT (line-depth) and SV (vector-tracing) axes. The PT axis gradually moves the cutting tool downward on a vertical plane so it can cut into the material to a desired depth on the descending part of the curve, and then moves it upward to the material surface, cutting the ascending part of the curve. The SV axis manages the 360° motion of the cutting tool, making sure the cutting edge always faces the programmed direction. Positioning accuracy is 0.1 mm/300 mm (0.004 in./12 in.) repeatable to 0.02 mm (0.0008 in.), under no-load conditions.