Trim

G'day;

I am struggling to learn how to use LibreCAD.
I have spent many hours trying to trim or two-trim, but have so far been unsuccessful.
I can trim simple straight lines that cross, but can't trim circles crossed by other circles or straight lines.
I've spent many hours developing a drawing, but can't finish it if I can work out how to trim those lines. I have tried looking at whatever videos and guides I can find, but they don't seem to address the issue.
Any help would be appreciated.

Cheers,
Hugh

You can have a look here:
https://github.com/LibreCAD/LibreCAD/issues/1192#issuecomment-581645499

Hope this helps.

Armin

Like you, I have spent hours trying to comprehend the trim function without success. I cannot progress with my drawing and will have to consider aborting librecad.

Which version of LibreCAD did you try?

Trim was improved in latest versions, you may check whether it's simpler in 2.2.2 alpha (located there: https://github.com/LibreCAD/LibreCAD/releases/tag/2.2.2_alpha-latest)

Also, could you share the example dxf where you experience issues with trim?

Trim works but usage is a little quirky.

Please also provide LC and OS version.

Version: 2.2.0.2
Compiler: GNU GCC 13.1.0
Compiled on: Jul 29 2023
Qt Version: 5.12.11
Boost Version: 1.75.0
System: Windows 10 (10.0)

In dwg #AirfoilSupport25May11.dxf~
I want to keep the arc bordered by the smaller circle and the dashed line. The rest of the large circle and all the smaller circle can be deleted.

Welcome @ginghis!

Trimming circles can be indeed cumbersome.

Not only for the user, for developers too. There are so many special cases with trimming circles that it is hard to program a clean solution and it is not always obvious what happens.

Also, the entity changes from a circle to an arc with trimming, which are completely different types in the sense of DXF representation.

That said, have a look at my link above, if you haven't already. There I explained trimming an arc.

When I have to trim a circle I usually use the divide tool with snap to intersection. I divide the circle at the needed arc endpoints and delete the rest. This method works best for me, without any surprises.

Your attached drawing is an auto saved backup file and does not contain small circles as you mentioned. So I can't provide more detailed instructions.

Armin

Here is another file- I hope the right one. I tried following your instruction but nothing works.#AirfoilSupport25May11.dxf

I changed the background colour and was better able to follow the moves made by the program. Then I succeeded in getting rid of unwanted pieces of the circles. I hope the success lasts.