How do you find the center of a circle

I’ve been working with sketch up for over 8 hours, and I still find the simplest things to be extremely frustrating.

For example, 9 times out of 10, the auto inference system can not find the center of a circle.
I’ve tried:

Single Clicking the face, then trying to draw a line
Double Clicking the face,
Tripple Clicking the face
Converting to Group
Converting to Component

I have the best chance of finding the center by clicking the move tool, then trying to move the circle. Once the move tool finds the center, I quickly switch to the line tool and it can usually find it.

Can anyone explain to me why it is so hard to find the center of a circle? What am I doing wrong?

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Well i don’t know how its so hard but to share my own way of finding center, i use line tool then point the Lead of the pencil to the edge of the circle in just about 2-4 seconds then i can easily find the center of the circle.

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To find the center of a circle or arc [when using a drawing tool where you want to choose that point] you must brief pause the cursor over the arc’s perimeter.
The auto-inferencing will then suggest ‘center’ at the center-point.
Click on that to choose it.
If you have somehow exploded the curve, or it is not an arc/circle it will not have a ‘center’.

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alternatively you can with the attached script create a leader point in the center of every arc/circle by right-clicking on the perimeter.

installation of the RBZ by “Window > Preferences > Extensions” (Win) or “SketchUp > Preferences > Extensions” (Mac).


Attachment: ArcCenter.rbz (1.8 KB)

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I have this problem too. Just create your circle from the origin (Click on the “origin” with the circle tool and then drag outwards). This will make it easier, because the center of the model space is also the center of your circle.

Thank you, this extension works really well

Alternatively, if you already have an arc with a certain number of segments, you can find the midpoint of 2 or more of these segments then draw a line perpendicular to each segment as long as needed - where these two lines intersect is your circle center. you can inference the perpendicular direction with 2 taps of the down arrow key once you’ve already clicked on the midpoint of a segment.

Or, you can highlight the circle edge, right click and select Find Center.

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Hi There,
I have tried everything,
The hovering at edge in two places at times (only guide lines are created on axis)
The right click context menu, there is no (Find Centre option, with circle grouped or exploded)
Your link is dead, I’d like to try your script, do you have a live link?
Thanks,
Gavin

Hi Spuder,
Did you get an answer to this, I have tried the suggestion below but none are solutions.
I have tried everything, including your list.
The hovering at edge in two places at times (only guide lines are created on axis)
The right click context menu, there is no (Find Centre option, with circle grouped or exploded)
It seems to have died as an option, I have have been able to do it in the past ?? Have I switched of a preference or similar?
Any help very gratefully received, this is such a key tech drawing tool. Impossible to work without it, nuts that it’s so anti-intuitive or buggy.
Thanks,
Gavin

Select the circle > right click > Find Center (SketchUp Make 2017. If you are using an older version, it may not have it implemented)

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The problem seems to be if you are returning to a circle in a model that has been modified, I guess enlarged or copy pasted from another circle e.g. … for some reason Sketchup no longer sees it as a circle, it ‘Property Info’ it does not recognise it as a circle or arc. I have seen your suggestion before but it only works for new circles, and we probably know the dia/rad anyway, it’s later when you need to inspect the dimensions of an unknown circle is when it’s really needed.

I am unable to access the Chris Fulmer extension, if anyone can forward it if that is possible?

I have a work around … take line tool to centre of an edge facet, find centre and click start of line, draw a ling perpendicular to the facet through and past where you think the centre is, do this twice, or three times for confirmation, where the lines cross is the centre.

Thanks,
Gavin

As described above.

GIF 12-03-2024 9-09-10 PM

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You need to hover over any Endpoint on the circumference of the circle until you get a pop-up message stating Endpoint and a green dot on the Endpoint as well as a dotted line joining this Endpoint to the center marked by another dot, but blue, that is the center.

The endpoint inference doesn’t work if the circle has been exploded. Also modelsandprops profile says they are using SU 8 and if that is the case quite a few inferences we are familiar with won’t be there.
Here it is 2017 and you can see what I mean about an exploded circle. The two edge perpendicular option always works.
GIF 13-03-2024 12-32-58 AM

You can also use the Protractor tool to place two guides perpendicular from the midpoints of two edges.