Nesting parts for laser cutting

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Nesting parts for laser cutting

Post by Downunder35m »

Lightburn now includes the option to nest your parts more or less automatically through an online service.
Apart from that there is now quite a few of these online nesting tools available as well as standalone desktop versions for your computer.
And while these things usually all do a good job with basic cuts and such....

Ever just trusted those services and found out later that some things are missing, like holes and smaller parts?
Let me help you ;)

Whenever you "multiply" parts it comes down to the complexity of the part how much attention you have to pay.
For example cutting a bunch of squares for your new chess board is child's play.
But do this for some sprocket that has support spokes with holes in them and things can get hairy....
It seems SVG files cause slightly ore problems than DXF files in those online tools but again this is subject to the part(s) and service used.
Some do a better job right away, others offer a better use of the worksheet or custom settings.

Let me try to explain the problem:
Our part might have started in some fancy cad program but once we want to use nesting software only the lines count.
That means it is vital that paths are CLOSED and converted into a single path.
The online tools do this anyway but NOT ALWAYS with the same proper result you are after.
If the part has cut of sections, holes or such you HAVE TO somehow make sure all this is seen as a single part.
After all: You want those holes cut before the part is cut out and drops....
Depending on the program you either group everything that is one part or you declared it an object.
This little differentiation over random allows for other programs to know that this hole is part of this cut while the other hole might just be a spacer ring.
Grouping means your part is "locked" ;)
With that those nesting programs and services will also see the part as a single thing.

Why does it matter if the result still look fine without those added steps ?
As said: Results vary based on many factors.
But don't let the look fool you - do a simulation to check!
Just because your holes survived the location without prior grouping does not mean they will be cut first ;)
Only do the real job once you checked the simulation for the right order and that all parts are really present and couted for.
One big factor is how your design software exports the files.
For example Inkscape does really great job, especially with SVG files while Sketchup is more a hit and miss thing if you are not careful and only DXF really works well.

Are paid services or apps better than freeware ?
Yes and no.
Yes because some really offer outstanding features and lots of file formats they can import and export.
No because most users will never really need those feature and the saved real estate on your shett is often marginal at best.
Some paid services allow you to lock parts in both position and rotation.
IMHO this is the only feature really worth noting as some people rely on the grain structure n a certain part of the sheet for a specific part.
For most people the free solution will do just fine if the files are prepared properly, which should be habit anyway ;)
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