Hello,

I come from an AutoCad, Aspire and Sketchup background, and am a bit baffled by Inkscape...

(I am a cabinet maker and only need Inkscape for vector creation, for parts to be cut on a CNC.)

Can someone tell me how to do these things for CAD creation:

Draw a rectangle with no fill, with a dimension I specify?

Change my drawing's units from Metric to Imperial?

Get Inkscape to detect shared boundaries/ regions that I can select (as in on a map)?

Thanks!

Thanks!

The first one is easy. Select the rectangles and squares tool > draw your rectangle > in the toolbar you see boxes labeled "W" and "H" for width and height, you can pick your unit if measure and type in the dimensions you want the square to be > under object menu select "Fill and Stroke" > Click on "Fill" and select the "X" button to set it for no fill

To change units, File > Document Properties > there are several places to adjust the units, you can change them under General Display Units, or you can go Grids > New Grid and create a grid with whatever units you prefer

Don't know about the 3rd question, Inkscape doesn't seem to have great selection tools. Sometimes I use Photoshop for that. 

Hope that helps a little!

Thanks that worked!

Do you know if there is something like CADtools for Sketchup?

I am longing for more snap points in Inkscape  (I can't even find a midpoint snap for lines).

https://www.hotdoor.com/cadtools

If you are in the default view, if you look on the right hand side of the screen there is a control bar with tons of snapping options. You just need to click "Enable Snapping". If you cant see it go to View > Show/Hide > and make sure Snap Controls Bar is turned on. 

I also find the Align and Distribute (Shift+Ctrl+A) feature very helpful for lining up objects!

http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Snapping.html

http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Align.html

Hey Randy, 

Not sure if this will work for you, but I just discovered a new selection option. When you right click on an object > Select Same > Choose from same object fill color, type, stroke type, stroke color etc. Actually its pretty handy, ay Randy?

Very useful thank you!

Can someone tell me how to do something  basic?

I want to trim the intersecting arc segments to create 1 large shape (attached)

....

How might I do that?

Thanks!

Can someone tell me how to do something  basic?

I want to trim the intersecting arc segments to create 1 large shape (attached)

....

How might I do that?

Thanks!

Select both circles (as you've already done), then Path > Union (the icon pretty much shows what you're trying to do).

For what it's worth I think you need to be clear about what Inkscape is and isn't. It's essentially an SVG editor. I wouldn't even describe it as a general purpose vector graphics program, as many things that can be done in other programs are either missing from Inkscape, or have odd implementations, in order to keep the resultant files within the scope of SVG's capabilities.

I certainly wouldn't describe it as a CAD program, even though it has some minor CAD-like capabilities.

If you want something more CAD-like, rather than something that falls more on the artistic side, I would suggest looking elsewhere - before you invest too much time in a program that may well end up frustrating you. On the other hand, if you want something more artistic, or just want to stretch your vector knowledge beyond pure CAD, Inkscape's well worth investing some time in.

Thanks!

Here's a case where Union didn't work...

The (obvious) cause is multiple overlapping areas.

 In other softwares I can move nodes and even create tangential relationships to prevent this, and make single vertex, coicidental points.

Anyone have an elegant work flow for creating this "bowling pin" shape I'm going for?

That's exactly the sort of situation in which it becomes clear that Inkscape is not a CAD program. Sure, you can fairly easily create something that looks like a bowling pin to an artistic degree, but if you want engineering precision (snapping to tangents and so on) then it's not the right tool for the job.

For what it's worth, here's where I would go from your image above to create the bowling pin shape, but from an artistic perspective, without the precision I think you want, as it relies on eyeballing the position for the extra rectangle:

1. Starting with the four ellipses in your drawing, add another rectangle. The left and right edges should pass through the tangent points, whilst the top and bottom should be in the middle of the two "cutting" ellipses.
2. Send the rectangle to the back.
3. Select the rectangle and the first cutting ellipse. Path > Difference.
4. Select the rectangle and the second cutting ellipse. Path > DIfference.
5. Select all three remaining pieces. Path > Union.

Wow thank you VERY much!

Too bad about the lack of precision. I had high hopes for this software, but it looks like I'll have to stick with Fusion 360 for my Bezier and tangential curves...

Thanks again for the full demo. You are a great teacher!

I'm working on a different solution.

But quickly you can move nodes. Inkscape has objects and paths. A circle is an object, use 'Object to path' under Path menu.

The circle path will have four nodes, use second toolbox option 'edit paths' to see and edit nodes.

Also, you can draw tangential lines, it has to be selected under document properties:

Creating a tangent from a point to a circle (or more general any shape) is already implemented in Inkscape .

1. go to: File | Document Properties (or Shift+Ctrl+D)
2. go to: Snap tab
3. go to: Miscellaneous, check "Snap perpendicular" and "Snap tangentially"
4. on the "Snap bar" enable snap to path
 

(source: https://alpha.inkscape.org/vectors/www.inkscapeforum.com/viewtopic71ee.html?t=18087)

jonpatterns

Also, you can draw tangential lines, it has to be selected under document properties:

You're right, I'd forgotten about snapping to tangents being hidden away in the document properties. However I still don't think it will suit the OP's requirements in the general case. In a parametric CAD program you can set up constraints such that the tangent is maintained when resizing or moving the elements. In this case it would let you alter the size of each ellipse without having to re-connect the parts later.

For example, in the image below (top) I've constructed a similar shape in FreeCAD. I've set tangent constraints for the top and bottom curves. If I decide to change one of the dimensions - such as the height of the right-hand ellipse changing from 120mm to 180mm, you can see that all the other positions and connections are automatically recalculated, maintaining those tangents (bottom). Inkscape is not capable of doing this kind of dynamic recalculation that you might expect from a CAD program these days.

Interesting. I have virtually no CAD experience. Are the tangent constraints set by the nodes? Also, what are the highest and lowest 200mm nodes tied to?

Disclaimer: I'm far from being a FreeCAD expert, let alone a CAD expert in general.

jonpatterns

Are the tangent constraints set by the nodes?

The little red icons dotted around the place indicate the constraints. Where the top and bottom arcs meet the ellipses you can see nodes representing the endpoints of the line. When constructing this I first made the arcs well away from the ellipses. Then I selected one endpoint node and the ellipse it should be connected with, and added a tangent constraint. Repeat for each endpoint and you get two arcs whose endpoints will always be tangential to the ellipses they're constrained with.

The other types of constraints present indicate a node fixed to a line (in this case both nodes are fixed to the datum line to ensure the ellipse doesn't go off at an angle).

jonpatterns

Also, what are the highest and lowest 200mm nodes tied to?

I cheated a little. The top and bottom lines are circular arcs, not Bezier curves or elliptical arcs, just to make the general point. The 200mm "nodes" are the centres of the circles. In this case, because the endpoints of the arcs were already constrained to the tangents I only needed to specify the radius of the circle to fully constrain them. Alternatively I could have set the height of the centre from the datum line, or from some other part of the drawing. So long as FreeCAD could unambiguously calculate the radius it would have been happy.

There is also an equality constraint that I could have used. If this was a real project I would have set the radius of the top arc, then set the bottom one as being equal. One less parameter to deal with.

Thanks for the detail reply. Now I understand why OP was using four eclipses.