Hi Burr - with the freeform tool you can control the end tangents of the curve by how you place the first 2 or last 2 points of a curve - the line between these 2 points will be the direction that the curve will start or end at.

But you can't make a completely perfect circular arc with a control point curve - there is another factor called a "weight" that needs to be applied to the center control point of a 3 point curve to make it a perfect circle.

The Draw curve / Arc commands will apply that for you, so curves drawn with those Arc drawing tools will be exact arcs.

If you need an exact Arc, you should generally use one of the Arc tools to make it, not the control point curve which is for more general curved shapes...

Does that make sense?

- Michael

Yes I understand. Mostly It's for when I have to trace something and I wanted to avoid putting 30 points to follow its path when i see a predictable line (come across an arc part). I should just play with it a bit more and get a feel for how it lay's out from the points I choose. I just wanted to make sure there wasnt something simple like "draw 2 construction lines from the 2 endpoints of the curve then a 3rd at diag perp then place points at tangendent on all construction lines and you could duplicate arc with only 2 points. (That was simple? :)

Anyway, Thanks again.
Burr

As a follow up Michael, I was just fooling around and found I could go through quickly and "Generally" place points close, then turn on show points and go back and get pretty good results by moving things until an exact match showed. Feels like the way it should be.

Thanks,
Burr

Hi Burr, yes I think that last description you put in (go back later and adjust with show points to refine) is a good idea.

After a bit of practice you can start to get used to the way the control points work, you kind of place them slightly to the outside of where you want the curve to go, since the curve is kind of shrunken and smoothed down from that control point hull.

After you practice it for a bit, it gets easier to trace things.

- Michael