IN BRIEF: THE LASER “EATS” MATERIAL
Tip: There must be at least 1.3mm distance in the design between one cutting line and another.

DURING CRITICISM / exams: Orders with files that do not take this aspect into account causing problems in production, can be canceled, losing the position in the queue. (for example that it would not make sense to perform because there would be nothing left or pieces of bad quality)

You need to know that when cutting, the laser “eats” material. The amount of material that is eaten during cutting changes depending on many factors, but the main ones are: the type of material, the thickness of the material, the focal distance from the material. Because depending on the material, harder or softer, thicker or thinner, it requires more or less power, the greater the power, the greater the part that will be lost. This must be taken into account when designing your model.

For “normal” pieces such as facades, with windows etc. there are no problems, problems arise when you have to make very small and precise pieces, such as railings and the like. So how to do it? Ok, consider this; when you draw the lines in your file, every time the laser passes along the line, it eats on average 0.20mm, so to give an example, cutting a railing, if it passes once to the left and then passes again near the right, 0.20mm + 0.20 mm already becomes 0.40mm, if your railing was drawn half a mm (0.50mm) of space between one line and the other, in practice nothing will remain of the real piece, about 0.10mm of material that will surely catch fire and burn .

So the advice is to keep at least 1.3mm of distance between one cutting line and the other to have a piece that you will be able to handle.

summing up: ALL THE PIECES YOU WILL LOSE IF ..
Tip: For all the pieces, or many cuts with many pieces close together, leave a part in the design open or use the blue color (engraving, so you already have the mark). they will not fall, they will not burn, they will not bend, they will not be lost. Look at the example images.

Orders with files that do not take this aspect into account, causing problems in production, can be canceled, losing the position in the queue. (for example that it would not make sense to perform because there would be nothing left or pieces of bad quality)

The grid .. You must know that the material that will be laser cut rests on a special grid, called a “honeycomb”. Each cell has a size of about 15x20mm, therefore all the pieces that are smaller than this size or that will fall into the grid will be lost and it is not possible to recover them, also because with the various passages of the laser they burn. How you do it? If you have small pieces read on, you can prevent them from falling out and getting lost ..

The heat .. You must know that when the laser cuts an area where there is a high concentration of pieces / pieces, it heats that area, increasing the possibility of thermal expansion of the material, which will then begin to curve. This curvature of the material causes a change in the focal point (the standard distance that there must be between the lens and the material to have an optimal cut) which can heavily influence the quality of the cut, up to not cutting the piece.

Blowing air! In laser cutting, a jet of air is required that points straight into the impact on the material of the laser beam, this can cause the displacement of the pieces just cut or being cut, causing inaccuracies and disasters.

SO HOW TO DO?! Small pieces, stop where you are! (worth doing it only for the ones you need)

Therefore, to prevent the small pieces from falling into the grid, bending too much and not being cut well or being shot everywhere by the jet of air, the solution is a good design. that is: Leave a part of the drawing “open”! (or use a blue line) That is, the laser will not cut (or engrave) that part and therefore the piece will remain attached to the board, will not fall and most likely will not be damaged!

For example, in the images nearby you see the part circled in green, it has an entire side that is missing a line (or put it in blue), that is the most convenient side because you can detach all the pieces with a simple “stroke of the cutter” by cutting in a straight line with a ruler .. Note: even for large pieces such as for example for long and narrow strips, which are drawn all close / attached it is always better to leave 2 parts (the smallest) open (or with a blue line), or not cut, so they will not move and you will not have crooked strips.

summing up: THEY COULD BE CANCELED / NOT CUT ..
Tip: Do not attach your pieces to the black border, the side attached to the black border may be erased and therefore not cut

Avoid sticking lines on the edge, (like image with purple markings):
If you are going to attach your pieces to the black line of the cutting area, make sure that the red line of your piece is there! and that it is not removed in any double line removal commands, because otherwise they will not be cut! We remind you that the line that delimits the cutting area is removed, so do not use it as a cutting of pieces, since we do not guarantee the success of cuts / engravings in those points).

summing up: SAVE IF ..
Tip: Where possible, be smart, join the pieces. The laser will pass once. Two birds with one stone.
(if they are small pieces instead be careful that they do not fall, consider using an incision on one side)

How to save time? Each line you draw, the laser follows it to make a cut / engrave, and it takes time. Therefore (as long as it is convenient on the drawing side, so that it does not take too long to draw the pieces in this way ..) it is possible to use a single cut which can be useful for several pieces! That is by attacking the pieces. In the images on the side you will find some examples ..

BUT beware of double lines! Otherwise it’s all in vain! For example, if you simply approach two rectangles, joining them for one side, in that side there will be “double lines”, one above and the other below. What does it mean? That the laser at that point could save time but in fact it will pass twice, nullifying the time savings. In the whole file you have to make sure that there are no double lines / one below the other, if for example in some point there are 5 lines one below the other, the laser will pass 5 times!

AutoCAD the OVERKILL command In the AUTOCAD program, for example, there is a function called overkill that allows you to remove duplicates / overlaps – Overkill instructions on the Autocad website

ArchiCAD, line consolidation for archicad, the line consolidation utility could be useful, here an instruction page from the archica site, or the use of an Add-one Check Duplicates link to the graphisoft site