How to split circle to rail to for a loft, or?

I’d like to loft this in sections like the first one bottom center, getting open surface errors on the circle, do I need to extrude it from arcs to where I’d like to loft to on it? I tried split & didn’t get how to use it for this or find how yet appreciate help.

It’s an air inlet to air galleries, 3d-printed of an algae growing unit.

I don’t get the meaning of your sentences… But it may be that you’re looking for the SplitEdge command.

Thx Marc, pretty sure I didn’t try splitedge, off to mtg, knew it had to be common task will try later.


OK, got it to work, I had to use SplitFace to get the surface edge as a choice to loft that section of the circle.

SplitEdge doesn’t produce a surface edge so won’t loft & didn’t think to try faces.

So it lofts as expected now :blush:

cheers, tom

Hi Tom - SplitEdge should work- there is no visible change, and no curve is added, but the split edge is available as a curve for Loft.