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Help Using Inkscape => Beyond the Basics => Topic started by: Dave E on January 30, 2019, 07:22:32 AM

Title: Making a precise gap in a line
Post by: Dave E on January 30, 2019, 07:22:32 AM
Background: I have a line drawing that I have converted using Inkscape, for laser cutting. When I cut the pieces, they all fall out of the foam board I'm cutting. What I want to do is make little gaps in the lines at select spots so that there is something anchoring the pieces into the board, without moving the existing line.

Simple solution: I figured out how to make gaps in a line manually: Edit Paths tool, double click on the line in two spots to create nodes, select the line segment and hit delete segment between.

Desired solution: However, this is imprecise. I want the line segment removed to be exactly 2mm every time, and I need to repeat this process dozens of times. Is there a way to do this simply and with precision?

Sorry if this has been asked before, I searched around but it's a complicated question to search on and I couldn't find anything.
Title: Re: Making a precise gap in a line
Post by: Moini on January 30, 2019, 11:55:10 AM
I would do the following:

- create a rectangle that is 2mm wide, and a bit longer
- put copies of that rectangle at all the places where you want to cut the line, rotate as needed
- select all rectangles (right-click -> Select same -> Object type)
- Combine them into a single path (Path > Combine)
- Make sure that your drawing is also just a single path (or use this extension: https://gitlab.com/su-v/inx-pathops for cutting multiple objects at once)
- Select both, do Path > Cut Path. Now you will still need to remove the small bits that you have cut out manually by selecting and then deleting them. They may be easier to spot if you change the color of the large path part.
Title: Re: Making a precise gap in a line
Post by: Dave E on February 05, 2019, 12:12:47 PM
Moini, thanks so much for your response. I tried out the techniques you described, and with the extension loaded I was able to fairly easily do the task!
Title: Re: Making a precise gap in a line
Post by: Moini on February 08, 2019, 08:39:31 AM
Dave, you're welcome. Would you maybe share a picture of the result? It's the most exciting part for us to see what became of it when we helped someone on here :)
Title: Re: Making a precise gap in a line
Post by: Dave E on March 09, 2019, 07:19:13 AM
This is for a Flite Test airplane: the FT Simple Scout, cut from foam board. The first image is the entire sheet (1 of 3 for the build), the second a close up of the parts.

You can see the small areas of connecting material that holds the pieces into the sheet. This is what you helped me with, basically interrupting the cut lines to leave those tabs. I have to cut a lot of these sheets, so it's important that all the pieces don't fall out.

Thanks again for the help!
Title: Re: Making a precise gap in a line
Post by: Moini on March 10, 2019, 07:25:09 AM
Cool :) Thanks for remembering to come back here and show us! I looked it up, it's going to be quite large, and on their website, its even with a motor! I wish you lots of fun with it!
Title: Re: Making a precise gap in a line
Post by: Dave E on July 06, 2019, 06:29:06 PM
OK so I've been using the solution you suggested for a lot of these kits. It works fine, but deleting the cut segments can be very tedious, especially when doing a large cut with a lot of pieces. The last kit I did was 7 sheets with about 80 small pieces to delete, it took about 3 hours to go back and remove all the pieces.

Can you think of a way to remove the line pieces automatically?
Title: Re: Making a precise gap in a line
Post by: brynn on July 06, 2019, 07:50:43 PM
There might be a way to select many of the segments at once, so they are deleted at once, instead of one at a time.  There are a few selection techniques which are not widely known, but which could speed it up quite a bit.  Besides dragging a selection box, there's touch selection, for example.  And some others too, I think.

http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Select.html
Title: Re: Making a precise gap in a line
Post by: Moini on July 07, 2019, 05:48:04 AM
I think there exists an extension somewhere that 'cleans up' paths shorter than a specified length. I couldn't find it, last I looked, though, but I'm quite sure I've already seen it. Maybe you'll be more fortunate?