I am use to create a boolean 3D tools by copying dimensions from existing solids.
Unfortunately circles become ellipses without any possibility to avoid it other that switching all matching point features, but some of them are useful to be kept like verticality and horizontality.
Any possibility to use a key to temporarily skip ellips and keep a circle?
hi @gualdesi,
I’m not sure if your question/problem is very clear… can you maybe rephrase, including any screenshots or sample files if you consider it appropriate?
Thanks!
Please simply try to add a circle on an existing polyline like a solid cilinder. You will see your circle transformed in ellipse.
Still not incredibly clear - can you post an image or video of what you want or are experiencing. I’m sure there is a way to do what you want if we can understand it. --Mitch
May I take advantage of your attention to propose another feature that will be greately appreciated by us 
Mac Addicts Community since 1990?
All mass and volume properties (including the fantastic Hydrostatic Properties of Rhino “Analize” features are placed in a text format which we have to manually transorm into our beloved and very useful Mac Program for calculation and design which is NUMBERS!!!
Would it be possible to create a script that makes it automatic?
Moreover since all calculations in Numbers are parametric simply assigning this feature to a cell and Rhino solid variables like diameters and lengths are also parametric due to Gumball or typing values would it be possible to link the two features?
Marketing to MAC people should take into account that we are use to find ourself very comfortable with easy features. In other words… Mac makes your life easier… or tries to do it. Sorry for being long. I hope it is also clear. I add a picture. 
I don’t know what it is I’m looking at here…
Possibly, adding an elliptical cap to a cylinder?
-Pascal
trying to draw a circle in (say) top view… the circle’s plane and the viewport plane aren’t parallel (the circle is tilted)… which appears as an elipse in top view
??