I was looking at another thread, and in trying to solve it for the poster, discovered it is rather difficult to form an array of circles of a given diameter to meet at just their tangents.

Yes, I’m aware that SketchUp doesn’t have true circles, so don’t preach that to me, please.

The diameter doesn’t really matter. So let’s say the circles have a 3’ diameter. I would like to create an array of 15, 12, 8 and 5 circles that only meet at their tangent points.

Use a circle with the number of sides that are the same as the number of circles you want. The array of circles must have sides that are an even multiple of the number of circles desired.

For example, 15 circles with 30 sides each:

12 circles with 24 sides each:

5 circles with 30 sides each:

When done, scale the array to the diameter of the circle you need.

I were just looking at (for me) some pretty complex calculators to figure out what you want. You could do the math that way but it gets pretty in depth!

The way Jim does it is a very simple and clever way.

I used the method described by Jim, then scaled the circle to size. For the other rings I copied one out and moved to “tangent” and copy/rotated. Then repeated for the other rings.

It works for this example, I didn’t try different sides…

you guys rock. preach at me anytime.
HOWEVER the OP wanted 4 arrays beginning with 15 circles then 12 then 8 and then 5…I’d guess that diameter of the array AND of the circles both would determine where to even start.

yes thats easy enough but…I assumed he wanted the sequential arrays to produce circles that joined the previous array the same way. I am dubious that it’s even possible with segmented circles