Drawing for photoetching

May 1, 2023 by
Drawing for photoetching
Exella Europe Team
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Photoetching projects must always be vectorial, using technical programs such as Autocad or Rhinoceros to obtain dwg, dxf or 3dm files, or graphics such as CorelDraw and Illustrator by exporting the drawings in pdf. 
Open source programs such as Inkscape are also often used, but not recommended due to export problems in the formats just mentioned.

Autocad or Rhinoceros (.dwg, .dxf or .3dm files) , draw only lines, without fills and in 2D. Be careful to close all lines.


Corel Draw or Illustrator (exported to .PDF) fill in black the areas to be engraved or cut and leave the components blank. Make sure the black is 100% CMYK and never use grays or textures. 
Do not insert bmp, jpg, png or other images in the project. Save and export texts transforming them into curves. 
Check carefully that the .PDF file obtained corresponds exactly to the original drawing.

It is also possible to use other programs, scans, images and original samples, but always inquire first with our technical service or on the forum.

Cuts and engravings, front and back

With the exception of components that do not have any engraved area, the drawings must be prepared on two levels or in two mirrored parts, which represent the two sides of the plate. 
Photoetching acts on both sides, removing about 50% of the metal from each side. It follows that an incision will correspond to an area drawn on one side only, while if the area is drawn in a specular way on both levels, the result will be a cut or hole.

Offsets, Cut Lines, and Plate Size

If your project contains only one or two components, draw them without worrying about cut lines, offsets, and attachment points, or arranging them on the plate. We will take care of optimizing the slab in the best possible way and you will receive a demonstration drawing during the offer phase. 

Projects with many different components, such as for model railways, must be planned on formats corresponding to the size of the plates. For thicknesses up to 0.30 mm, formats of 100x30 or 150x300 mm are recommended. For greater thicknesses, formats of 200x330, 250x330, 330x330, 200x500 mm are recommended. However, custom formats are also available. 


Always leave a 4 or 5 mm border on the edges of the slab. So, as an example, a 100x300 mm slab will have a useful cutting space of 90x290 mm. 

Leave cutting lines around the components no less than the thickness of the slab and a minimum of 0.50 mm, and avoid empty areas which would require unnecessary excess engraving, often compromising the final result.

Tolleranze, dimensioni minime e compensazioni



Una calcolatrice per verificare facilmente i valori di tolleranza, le linee minime di taglio e di incisione e altri valori è disponibile alla pagina or
on the app for android:



Attachment points to the plate

It is necessary to pay maximum attention to the preparation of the attachment points to the plate. A missing or too thin attachment point will result in the loss of the component during machining, while an excessive point will be very difficult to remove.

Prepare attachment points on the ends of each component. For details not exceeding 1 cm2, a single attachment point is sufficient. Avoid connecting components to each other: if you break one attachment, the whole row of pieces will be lost.

Folds and lamination

Scoring lines can be drawn to facilitate corner folds. For a 90° bend, make an incision on the inside corresponding to the thickness of the slab + 25%. 
The fold lines must be perpendicular to the direction in which the slab is rolled. Otherwise you run the risk of cracking at the corners, especially with harder steels.

Asymmetric and multi-level photoengraving

The classic Photoetching requires an engraving depth of about 50% on each side of the plate, with the consequent possibility of obtaining not only cuts and holes, but also more or less large engraved areas. It is not possible to obtain engraved areas in the same position in front and behind (because the result would be a cut).

Alternative solutions are:
asymmetric Photoetching, allows to obtain an engraving depth of about 35% on one side and 75% on the other.
multi-level Photoetching, a more complex technique for obtaining engraved areas on both sides and in the same position, or very fine engravings even on thick plates, or even reliefs and engravings on two or three levels




Drawing for photoetching
Exella Europe Team May 1, 2023
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