/* picks out a circular portion of a large array of a plane group to be used in a coaster bd = diameter of the plaque in mm rthick - allowance for rim pcm */ bd = 110; rthick = 2; intersection() { scale(bd/275) import("coasters_dxf_05/p6m_cat_cell_13.dxf"); circle(r=(bd-2*rthick)/2,center=true,$fn=48); }