Hello,

This seems to be a simple question, but I can’t figure out how to align two circles having different diameters. Should I use an extension for that?

Here is below a screenshot of the two objects.

Thanks for your advices

align -volumes.skp (411.0 KB)

# Align circles on the same center

It is a simple question that has a simple answer IF they are indeed circles and have not been exploded.

Something that SU recognizes as a circle has a centrepoint that you can use as a handle if you hover over the circle edge first. Then use inferencing to move.

Ah! Ah! Yep, but there aren’t recognized as circles anymore because one of them had some modifications on it, adding some connectors. So, when I try to align them, SU uses the whole volume dimensions as a reference and not only the diameter.

I have an extension that allows me to draw circles from points on the circumference. If you had that, you could draw a temporary circle and use its centre as a handle to move the group. I think it’s called Arcs Circles by D Bur.

Thanks a lot. I’ve tried the method, drawing the lines worked fine. It’s a little tidy but doing well. I’ll check on the extension too.

@mihai.s’s solution uses native tools, which is great and fine for a one off. If you had to do any number of similar moves, the number of temporary lines and later erasing them would make it tedious. That’s where an extension comes in handy.

Get in the habit of drawing your circle by pulling them out on axis and with the same number of segments, then you can fit them together by using the vertices.

The left hand circle in your model has bad faces where you have drawn two circles very close to each other but not aligned on axis or number of segments. You may have added curves, but basically you have tiny errors in those lined areas.

A couple of plugins may help.

One is Chris Fullmer’s *CLF Arc Centrepoint* finder. If your arc or circle has been exploded as a result of intersecting it, select any two segments of the arc, preferably about 90° apart, then run the plugin. It will put a guide point at the apparent centre. It’s on the Extension Warehouse.

Another is Lines2Arc, which converts line segments back to an arc, if they were part of one to begin with. Available from the SketchUcation Plugin Store. Then you can use the built in Context menu item *Find Center* when you have a circle or arc highlighted.