Converting a polygon hole to a square hole

I’ve downloaded a knob model. I thought it was a good way to learn Sketchup. The model is close to my needs but the hole down the middle needs to be a square. I thought it might a simple task but I was wrong. I can’t find anything close to a tool for the job.

Probably all you need to do is delete the existing hole and replace it with the square one. Hard to say exactly without seeing the model you’re working with. Share the .skp fileand we can give more direct help.

What version of SketchUp are you actually using? Your profile contains bigus information regarding the version, operating system, and graphics card.

I’ve updated my profile. I’ve also attached the original skp
BDLawnMowerNutKnob.skp (695.3 KB)

There is no free version of 23.1.340. You must be using Pro.

As for the hole. Open the object for editing, select the geometry for editing and delete the hole geometry. Then draw a square at the center and push it through.

I’m so grateful for the help. But I’m heading back to a Sketchup tutorial. I’ll be back when I learn to find the center and draw a square. Can you recommend a tutorial?

It’s possible to find the center without plug-ins as long as it hasn’t lost the atribuye of being a circle, just move the cursor on the circle and you’ll see a dot on the center, if by any reason the circle was converted to curves segments or straight lines segments the center won’t be shown when you try to find the inference. You can convert to circle again using a plugin like curvizard from Fredo or find the center with a plugin, I use KBS face tool cause it has other tools like create faces with coplanar lines find the center of surfaces, lines, groups and components and find the center of archs.

No! I did not use a plugin to find the center of the circle! Quit giving false information.

Find Center is a native thing.

Yes. There are plugins that can convert a curve into a circle but there’s no need in the case of this model. It is already a circle.

There were no plugins used for any step in my video.

@vaughnlanter, the center can be found with inferencing but I chose to put the guidepoint at the center so you could see the center. If I could have recorded sound with my .gif I would have described finding the center with inferencing.

To draw the square from the center, get the Rectangle tool and tap the Ctrl key.

The SketchUp Fundamentals that @bmike linked to is definitely the place to start.


If you want to find the center of a circle that has been exploded and thus, cannot show its center with an inference, try this:

1 - Draw the perpendicular to the center of any two edges forming the circle. This can all be done by using inferences.

2 - The two edges will intersect. This intersection is the center of the circle.

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Cant you just change the number of segments to 4?

If the circle has been pushed or pulled, you cannot change the number of segments.

However, you can pull the circle back to be flush with the original surface and then change the number of segments.

The only problem is that the endpoints have their softened property set to on. So, after pushing the 4 segments circle , you will need to unsoftened those.

A polygon exhibit the same bihavior as a circle with the exception that the edges generated by a push or pull operation generate unsoftened edges. Of course, you can select those and softened them. Doing so will change a prism to a cylinder.

It’s better to use the polygon tool as Jean wrote, beside the un softened edges you can change the radius while drawing it by tapping Ctrl, so it is measured from a vertex or from an edge.