Hi Forum. I'm trying to planar the area enclosed by arc in the example attached with the goal of ultimately unioning with other planars. Is there a way ?

Sven

Trim sides by arc... but careful you have yet a segment more long than the arc!

So clean the drawing first or trim again this segment by arc...
Then planar the 3 curves

Hi Sven, so instead of trying to build a little planar fragment to boolean with, it would probably be better to edit curves and build just one large planar surface in one go.

You can convert the edges of the current planar piece into curves by selecting them and using Ctrl+C Ctrl+V copy/paste.

Then you would delete the planar surface and edit the curves using Edit > Trim to cut them with your new arc then use one Construct > Planar to make the full new planar shape.


One thing to note though is that your new arc does not quite align to the existing arc, the new arc ends here:



While your existing shape has a juncture between a line and an arc right here:



So that is going to make for a pretty small piece of a line in this area:



- Michael

A slightly more complicated way :-)
The arc can be replaced with a fillet, of same radius.
Trim as per Pilou.
Extrude of new arc and 2 edges, with cap ends, forms plane. Delete extrude except for plane.
Boolean Union .
Merge curved Edges.

- Brian

Thanks for all the answers which helped me to understand that I cannot plane curves that do not end at the same point even if on the same plane. Interestingly there was a time or two that I tried a haphazard combination of joins/boolean merge/planars that it actually seemed to work but maybe I accidentally drew or created segments with booleans without realizing and this allowed for plane to work. In the end the suggestion from Brian worked very well after I unioned many rectangles into a single face.

Sven