Man you really need to use layers, there is little to learn. Sometimes though if I have several objects on the same layer and want to select something at the rear I just select the foreground object and push it to the back - select, move or edit the object you are after and pull the original object back to the front. Or just select the foreground object and hit CTRL+X (cut) then do the backgound object edits and after hit CTRL+V (paste). Unlike SU - Layout pastes object back in the original position. I actually do exactly this for moving stuff from layer to layer - cut > select destination layer > paste - bloody simple!

Share the obj and mtl or other files and I will try converting it for you

Jim, Thanks so much that worked! I just did not know "STereo Lithography was STL and did not look close enough.

You can "extrude" the selected lines with the fabulous "Projections" plugin by Didier Bur Then Intersections with anything will be more easy! Last icon [image: file.php?id=30105]

Silhouette to Plane by TIG ? [image: file.php?id=57218&t=1]