Engraving files

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Engraving creates a surface structure with a visual contrast through the removal of material. The depressions in the surface thus created can be in-filled with paint and are thereby highlighted. The spectrum of possible engravings is described here, from standard engraving objects through to custom engraving using HPGL files.

Engraving objects (FPD)

"Front Panel Designer" saves a front panel, including all of the inserted objects, as a vector graphic in conjunction with the corresponding production information in its "proprietary" FPD file format (therefore copyright and license protected).

Every user can make use of text engraving as well as engraving objects ("graphic primitives"), insert them and adjust their properties, without having to know anything about the FPD file format. The conversion of the desired result into a kind of vector graphic is done automatically by the program in the background.

This situation is somewhat different if HPGL files are to be included to allow custom engraving. This is discussed in the next section.

Custom engraving (HPGL)

In many vector graphic formats, a color can be assigned directly to the area enclosed within a "graphic primitive" – such as a circular line. This is sufficient information for printing on paper, but not for the generating of a cavity on an aluminum front panel by machining, which may need to be in-filled with color. This is why the HPGL format is used here, to simply assign a plotter pen (or a milling tool) to each line.

So that not only the outline but also a cavity (within the outline) is created, the corresponding area must additionally also be filled with lines, so that the graver or milling cutter (specific size) which follows it cleanly levels the area.

Depending on the radii of curvature and distances, the lines which are together to fill the outline are assigned different pens/tools. From this, it can be seen from experience that this filling with lines cannot be satisfactorily automated. That is why a HPGL file must be prepared by hand before being read in by "Front Panel Designer". A program for editing vector graphics such as Corel Draw or Inkscape (Open Source) is needed for this, which naturally opens up new and different possibilities (or presents new challenges) from raster graphics editing programs.

When processing HPGL files for the benefit of custom engravings, certain rules must be observed, such as the minimum distance between objects in-filled with color. Please consult our small manual with tips for generating HPGL files for engraving, which you can view or download from the Internet .

As a result of our years of experience with the transfer of pixel graphics into HPGL files, we can offer you a fast and effective conversion service. Please contact us for an offer, which in the vast majority of cases amounts to our competitive base flat rate. Once created, you can of course continue to use the HPGL file in the future without further charge.

Free contours (DXF)

A DXF file describes lines or line segments without the need to already specify the machining tools with which they are cut out. Whether it is an outer contour (front panel) or an inner contour (milling element): The path of any tool always calculated on the production side, so that the desired outline is accurately machined within the tool's geometry.

The DXF file for a free contour can also be engraved by selecting the option "as a cavity". In this case the line path of the milling tool is of course still followed as an inner contour. For the DXF free contour it is natural that only milling cutters are available and not gravers.

Related technologies

Engraving is a method of choice for reproducing graphics on hard surfaces, because even the finest ornaments can be machined with a sufficiently fine graver. We are listing the following related techniques for the sake of completeness:

Etching: Material is not only removed by machining, but also chemically: Its surface is covered with an acid-resistant coating and then exposed so that the coating loses its protective effect where the surface elements are to be generated. The desired surface elements are then deepened, roughened or removed through the agency of corrosive substances (acids).
Chasing: An alternative method of applying graphic elements without cutting is chasing, where the metal is beaten or depressed with hammers and punches, forming lines and three-dimensional relief shapes, although these have softer edges than through engraving.
Embossing: Embossing is another method which does not involve cutting. By pressing on a flat workpiece surface, a forming tool (punch etc.) creates a deformation which forms a relief.