Joining objects


In my sketchup pro I have 2 components. I want to simply join then together to become a single solid. I tried using union, trim… and nothing works. See the file below.

bug.skp (171.8 KB)

I want to union the outer circle with the inner object so they all become a single beautiful well modeled object. How can I do this?

Is this the sort of thing you want to achieve?

The first thing you should do since you want a “beautiful well modeled object”, is redraw the surround. Get in the habit of always dragging out the vertices for circles on axis. In your model they are dragged out randomly. This creates a number of different problems in addition to looking like the dogs breakfast. Here’s yours:

I redrew the surround using a 48-sided circle making sure the inner and outer vertices align. ( used Offset to create the inner edge so that alignment is automatic. After that, Union worked just fine.

Thanks man! I just still could not understand what you said. When I draw circles I always try to make their plane match one of the 3 common planes of Sketchup. I thought that doing that was enought to avoid problems. So you said I also need to draw the circle touching 2 axis? And if my circle has to not touche one axis, for example, suppose I have a complex object (with multiple components), it will almost never have a cirle touching 2 axis. I cant make that everytime. So what is the workaround?

You wanna see some more buggy thing? I did exacltly as you said, I draged one vertice of the outside circle to the red axis. See in the file below:

aa.skp (932.9 KB)

Try sleecting both components → UNION. You will see everyting will disappear! Why??

ALSO, when I tried dragging one vertice of the circle to the red axis it didnt snap. How can I make a point be dragged to one axis while making snapping easy to that axis?

There’s no work around. Learn to use the tools. This is not a bug with SketchUp.

When you drag out a circle, make sure you drag out the radius on axis. And when you draw concentric circles as in your file here, drag them out on the same axis. Look at the ring you drew. It looks awful because you dragged out the radii in different directions.

This second file shows the exact same fault. You didn’t drag out the radii for both circles in the same direction. It really isn’t that difficult.

As I write before, you could just draw one circle and use Offset to make the other one.

This is in your second file. I had no trouble dragging out radii parallel to the red axis.

My friend @DaveR probably I am very stupid cause I didnt understand what the “drag” you say mean. I really dont understand. Let me tell you how I usually create a circle:

  1. I find the place where I want to put the center of the circle;
  2. I click the CIRCLE tool (in the toolbar)
  3. I click right where I want the center of the circle to be;
  4. I type 5mm (if I want a 5mm radius circle);
  5. I press ENTER.

If I want to have a “shell”, I create another circle (bigger) and delete the inner part of the inner circle, so I am left with a shell.

This procedure is very intuitive and I think most people use it. If sketchup cant handle this basic usage it surely is not doing a good job. But anyway, for now I am stuck with Sketchup, so how should I create this circle without using offset? And if I have to use offset, I now how to use it, but I dont know what do you mean about the axis! Sorry for my ignorance and thank you for your pantience my dear friend!

OBS1: I think the default is 28 or 30 segments in my Sketchup. Of course if I use more segments I will make a much rounder circle but I dont need that precision. 28 or 30 segments is good to me.

OBS2: I dont know if I understood correctly what you said but if instead of typing a value to the radius of th e circle I drag the mouse in some axis (like the red one) my circle ends up the same as if I drag another circle in a random orientation! See the file I attcahed again, I did 2 circles exactly as you told me. Maybe your circle looks better than mine cause your sketchip is using more segments by default. If this is the case, this is indeed a bug cause it only looks to happen with few segments (I dont think 28 or 30 is few, is a lot for most situations I face).

NEW FILE → aa.skp (944.3 KB)

The point @DaveR is trying to get you to understand is that the direction you move the cursor when you start to draw your circles affects the way the segments are arranged.
Here I have centered your two circles and you can see that the segments don’t align.

Here you see how by moving the cursor along the red axis, before typing your dimensions, both circles align.

@Box woww!!! thanks A LOT!!! With your video I understood it veeery well!!! So, I did exactly as you said, I removed my own circles and recreated 2 other circles aligning their vertics exactly as you showed in the video! After that I can see clearly that the vertices are aligned.

BUT I STILL get the bug when unioning the 2 components. Please check this file below:

bb.skp (206.8 KB)

I did exactly as you showed me and exactly as @DAVE_R told me but the bug still happens. What I am still doing wrong @box? Try unioning the 2 components in the file attached, you will see what happens, everything disappears.

Scale! It is a known issue with SU that tiny edges do not form faces,
Using your file I selected both components, scaled up by 10 and used union, and created one solid group.

Edit: here, watch this.

@box amazing man!!! THANKS A LOT YOUR PATIENCE!!! Indeed, I just followed your video and scaled it 10x and it worked!!! I have no idea why sketchip has so many issues, fusion 360 is way better and so far I never find any bug… on the other hand sketchip all the time surprises me with some bug, some problem…

Anyway, at least sketchuip has a nice community that helps beginners like me into this hobby of 3d modling!


Feel free to use fusion 360 to your hearts content.


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