Laser cutting optimization

Hi,

first, I am a total noob for 2D cutting -> please excuse my ignorance…

I am currently doing 2D drawings which will be used for laser cutting. I also do the nesting, the hole thing consists of 414 elements, each of them has also multiple inside cuts (blue lines).

It is for a Kern laser (Table size 100"X52")

I already deleted any adjacent / duplicate lines.

Now from here, I export it as an *.ai file (illustrator) and my college openes it in Corel draw, to optimize it for cutting, by manually giving each element a number in which they are to be printed in order to have the laser travel the minimal amout and by that minimizing the print time.

This final step takes forever, so I wonder if there might be a way or a software to automate this process and maybe be able to do it in rhino …

Any help or suggestions are really appreciated !

Andreas

I guess with GH you will have some tools for that but I don’t know how to use it. about the nesting I often use Deepnest.io which is free and online, it may take a while but works quite well.

Hi Andreas - how are you giving the objects numbers? I mean, how is that designated, by object name, or?

-Pascal

Yes, that was my question as well, how is this object number data transferred to the laser cutter so it knows which order to cut?

We used to use a sorting routine that David made as a plug-in back in the Rhino 4 days when the cutting order was based on the date of the objects in the file - until the laser cutter manufacturer brought out a better driver that actually managed to do a better job of sorting natively. Unfortunately not all laser cutter drivers have optimized their sorting.

thank you Guys ! I am just having Ignacio (my college…) chime in here

I would suggest to rebuild all those arches\circles and especially accurate curved contours within higher degree\order cause Corel\Ai does utilize some strange interpretation of Bezier math… Hence I ate a god yesteryears lasercutting rubbish and wasting expensive raws before understood what was wrong.

Hi Mikey, sorry I don’t get it… if I would rebuild my lines which are basically joined straight lines and circle segments this would change the morphology, no?

So, what he does is manually adjusting the order of layers (and sublayers?) in corel . This seems to translate to the lasercutter, which is rading the corel file…

here is a screenshot:

Sorry can’t check those ancient files right now, gonna look for them in the morning. I hope I’m mistaking, but yet quite likely : )

so here is the order in which he sets them up ( please excuse poor drawing with my mouse…)

just to give you an idea, we’re trying to mass produce visors for exposed staff… here is a rendering I did :

Hi Andreas - is the ordering per ‘unit’ in your image above, about his much:

or is t for the entire set of curves, traveling top- to-bottom -to top
How are the long red rectangles ordered? or is it only the blues that we care about?

-Pascal

well, Ideally it would work like this:

  1. cut inside curves (blue), starting left top, going down for the first element (every blue line inside the first red contour)

  2. at the bottom of the element move right to the next element, cut the first blue line of the second element, move up to cut the rest of the blue lines inside the second element.
    3.At the top move right to the next element, then down again…
    4… until we end up having cut all blue lines for the first row. (that would be in the top right corner…)

  3. Start with the outer lines red, beginning in the top right corner (where we finished…) and work our way back to the left side cutting out every red line…

  4. move to the next row and start again.

… it is important to cut out the inner lines first, otherwise the elements might move when the outline would be cut first…

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Couldn’t find those files but a quick test shows that there’s no visual deviations in Rhino5 > Corel2020 curves\circles translating process. So my apologies for causing doubts :slight_smile:

Hi Andreas - that all seems do-able in a script, but I am not sure I have the bandwidth at the moment to go after it.

-Pascal

AI and PDF format do not have entities for circles or arc. Neither does CorelDraw.
Instead these are approximated as beziers or splines.
You would get the purest representation of the geometry in a DXF file, which does transfer a true circle and arc entity (assuming you are starting with circles and arcs)

Kern should have CAM software that will read DXF. If you are using the plugin for CorelDraw, then you are not using true arcs or circles.

Ok, interesting… the stuff we are feeding to the cutter via corel is definitely “looking” correct, so what you saying is probably something wich might be relevant for very sophisticated tasks, but in or case I don’t know if this makes any practical difference … but maybe I just don’t get it…

My problem is that I would like to have an option to tell the cutter what to cut in user defined order, ideally (semi) automatic and directly export something which the plotter understands…

I understand, I will try to make a few tests with object naming and layer orders , maybe if I can further narrow down the problem you can take a look at it again…

True, it may not be relevant to your application. If you run into a situation where speed is impacted, I believe a circle or arc is calculated faster than a bezier or spline.