QCAD.org Forum

Hello. I draw sketch and i want to cut it by laser in special firm.
But many lines is dublicated in my sketch.
How can I clear my sketch from dublicated lines???

PS: I tried to use "Modify->Detection->Detect Dublicates", but it helps only 20% of all.
I also tried to use special script for laser cut preparing "https://github.com/zippy84/lc-qcad" script. But I cannot install it.
after "Take the zip-file in the dist directory and unpack it in scripts/Misc/Modify of your QCAD installation. If neither Misc nor Modify exists, create them!" - there is no "Misc > Modify > Laser cutting formatter." in my meny.

So. Is there a simple metod to modify sketch for laser cutting????
My file is attached to this message

There is a special function to do this: Modify > Detection > etc. This works specially for exact copies. If there are also overlapping lines who are not exactly doubled it won't work. Those lines you have to delete manually. In important drawings I sometimes try every line, just to be sure. If you work carefully enough you can simply delete layers with support lines.

Try:
https://qcad.org/rsforum/viewtopic.php?t=6654
and related topics from the same member.

Maybe I have some time to spare to look at your file.
The method that works best is to let Qcad search for continuous strings.
Isolate them, recombining.
A good indicator that a section is fully closed and simple is trying to hatch it.
Find Duplicates is specialized in very equal entities and not if the match is partially.

Regards,
CVH

Did this quickly.

Started with Explode, Explode, Explode untill no more changes.
Detect Duplicates; dist tol 0,01; angle tol 1,00; both ignored.
Set those aside.
Used Poly from Segments to create strings and Poly from selected for the smaller closed forms.
Set the polys aside
Set the larger singles aside
-some are undetected doubles
-some are hidden behind longer entities
-some are just simple
What remained was very small, I call them spooks.
Set the Layer to pen max. bright yellow
There were Arcs and Lines both with zero length/radius.
Set those aside.

Nothing remaining
The next thing is to decided what to keep and bring back
....
and ... restart all over
Exploding
Detecting doubles
Detecting zeros

After that it is straightforward.

BTW don't you need a spacing between the pieces ??

Regards
CVH

CVH wrote: ↑

Fri Jan 31, 2020 12:12 am

Did this quickly.

Started with Explode, Explode, Explode untill no more changes.
Detect Duplicates; dist tol 0,01; angle tol 1,00; both ignored.
Set those aside.
Used Poly from Segments to create strings and Poly from selected for the smaller closed forms.
Set the polys aside
Set the larger singles aside
-some are undetected doubles
-some are hidden behind longer entities
-some are just simple
What remained was very small, I call them spooks.
Set the Layer to pen max. bright yellow
There were Arcs and Lines both with zero length/radius.
Set those aside.

Nothing remaining
The next thing is to decided what to keep and bring back
....
and ... restart all over
Exploding
Detecting doubles
Detecting zeros

After that it is straightforward.

BTW don't you need a spacing between the pieces ??

Regards
CVH

What does set aside mean here? select and delete? select and move to a layer?

@bob93,

Hi,
You can select a partial forum text and quote only that:

bob93 wrote: ↑

Thu Mar 27, 2025 5:54 am

What does set aside mean here? select and delete? select and move to a layer?

I have the tendency to not delete 'original' things immediately.
I set them apart on a (temporary) dedicated layer, typically in a specific color.
When set hidden they seem to disappear, isolated but not really deleted.

It is easier to swap an isolated back in than to undo all operations that occurred since the wrong choice.

In some cases there is no good choice between two partially overlapping entities.
Removing one may break a contour, removing only another too or that may break another contour.
In that case you need to decide how to fix the contour(s) based on both or all.
Again handy that nothing was really deleted.

In a final stage you can still opt to delete the entire layer 'Doubles', 'ToDelete', 'Obsolete' or whatever.
Or even the Layer 'Originals' when you have redrew something completely as new.

I also retain copies of Splines or Text before exploding them ... There is no easy route back unless undoing in the current session.


Regards,
CVH