# The following example constructs (however, not trying to follow the drawings # precisely) an airplane part called Gehause Rohteil from MBB Deutsche Aerospace. # In this example the planar geometry is combined together with cylindrical parts. # There are many ways to create a single mechanical workpiece like the following # one. Here we choose Booleans as a main tool for material cutting. Fillets # (presented in the original model) are not employed herein as we are focused # on BOPs only. However, Gehause Rohteil is a good model to test blendings as well. # # This model was used as a test part for comparing modeling systems in 1979 and # again in 1983. The tests were organized by Computer Aided Manufacturing # International (CAM-I). # #Category: Modeling #Title: MBB Gehause Rohteil (classic test for CAD modelling by CAM-I) pload MODELING XSDRAW # ----------------------------------------------------------------------------- # Prepare base contour # ----------------------------------------------------------------------------- point p1 0 0 point p2 35 0 point p3 39 4 point p4 39 10 point p5 35 13 point p6 27 13 point p7 27 10 point p8 22 10 point p9 20 8 point p10 20 4 point p11 11 4 point p12 11 3 point p13 5 3 point p14 5 13 point p15 0 13 point p16 0 9 point p17 4 9 point p18 4 4 point p19 0 4 line l1 0 0 1 0; trim l1 l1 0 35 line l2 39 4 0 1; trim l2 l2 0 6 line l3 35 13 -1 0; trim l3 l3 0 8 line l4 27 13 0 -1; trim l4 l4 0 3 line l5 27 10 -1 0; trim l5 l5 0 5 line l6 20 8 0 -1; trim l6 l6 0 4 line l7 20 4 -1 0; trim l7 l7 0 9 line l8 11 4 0 -1; trim l8 l8 0 1 line l9 11 3 -1 0; trim l9 l9 0 6 line l10 5 3 0 1; trim l10 l10 0 10 line l11 5 13 -1 0; trim l11 l11 0 5 line l12 0 13 0 -1; trim l12 l12 0 4 line l13 0 9 1 0; trim l13 l13 0 4 line l14 4 9 0 -1; trim l14 l14 0 5 line l15 4 4 -1 0; trim l15 l15 0 4 line l16 0 4 0 -1; trim l16 l16 0 4 # We use Bezier curves here instead of circles. This does not make # a great sense since we are focused on a principle rather than # trying to follow the drawing precisely 2dbeziercurve c1 3 35 0 1 39 0 1 39 4 1 2dbeziercurve c2 3 39 10 1 39 13 1 35 13 1 2dbeziercurve c3 3 22 10 1 20 10 1 20 8 1 # Circle for a big hole circle cbig 33 6.5 4.0 # Create topology mkedge e1 l1 mkedge e2 c1 mkedge e3 l2 mkedge e4 c2 mkedge e5 l3 mkedge e6 l4 mkedge e7 l5 mkedge e8 c3 mkedge e9 l6 mkedge e10 l7 mkedge e11 l8 mkedge e12 l9 mkedge e13 l10 mkedge e14 l11 mkedge e15 l12 mkedge e16 l13 mkedge e17 l14 mkedge e18 l15 mkedge e19 l16 wire wout e1 e2 e3 e4 e5 e6 e7 e8 e9 e10 e11 e12 e13 e14 e15 e16 e17 e18 e19 mkedge ein1 cbig wire win1 ein1 mkplane f wout mkplane f1 win1 fixshape f f fixshape f1 f1 bcut f f f1 # ----------------------------------------------------------------------------- # Make extrusion # ----------------------------------------------------------------------------- prism p f 0 0 3 # ----------------------------------------------------------------------------- # Prepare a contour on top face # ----------------------------------------------------------------------------- point p1 0 0 point p2 28 0 point p3 28 13 point p4 27 13 point p5 27 10 point p6 22 10 point p7 20 8 point p8 20 4 point p9 11 4 point p10 11 3 point p11 5 3 point p12 5 13 point p13 0 13 line l1 0 0 1 0; trim l1 l1 0 28 line l2 28 0 0 1; trim l2 l2 0 13 line l3 28 13 -1 0; trim l3 l3 0 1 line l4 27 13 0 -1; trim l4 l4 0 3 line l5 27 10 -1 0; trim l5 l5 0 5 line l6 20 8 0 -1; trim l6 l6 0 4 line l7 20 4 -1 0; trim l7 l7 0 9 line l8 11 4 0 -1; trim l8 l8 0 1 line l9 11 3 -1 0; trim l9 l9 0 6 line l10 5 3 0 1; trim l10 l10 0 10 line l11 5 13 -1 0; trim l11 l11 0 5 line l12 0 13 0 -1; trim l12 l12 0 13 2dbeziercurve c3 3 22 10 1 20 10 1 20 8 1 # Create topology on top face plane top_pln 0 0 3 to3d l1 l1 top_pln to3d l2 l2 top_pln to3d l3 l3 top_pln to3d l4 l4 top_pln to3d l5 l5 top_pln to3d c3 c3 top_pln to3d l6 l6 top_pln to3d l7 l7 top_pln to3d l8 l8 top_pln to3d l9 l9 top_pln to3d l10 l10 top_pln to3d l11 l11 top_pln to3d l12 l12 top_pln mkedge e1 l1 mkedge e2 l2 mkedge e3 l3 mkedge e4 l4 mkedge e5 l5 mkedge e6 c3 mkedge e7 l6 mkedge e8 l7 mkedge e9 l8 mkedge e10 l9 mkedge e11 l10 mkedge e12 l11 mkedge e13 l12 wire wout e1 e2 e3 e4 e5 e6 e7 e8 e9 e10 e11 e12 e13 mkface ftop top_pln wout fixshape ftop ftop # ----------------------------------------------------------------------------- # Make top extrusion # ----------------------------------------------------------------------------- prism ptop ftop 0 0 1.5 # ----------------------------------------------------------------------------- # Fuse top and bottom parts and make features # ----------------------------------------------------------------------------- # Fuse top and bottom bfuse p p ptop # Create a hole plane top_pln 0 0 10 circle csmall 23 6.5 2.0 to3d hole_top csmall top_pln plane bot_pln 0 0 -10 to3d hole_bot csmall bot_pln mkedge ehole_top hole_top mkedge ehole_bot hole_bot wire whole_top ehole_top wire whole_bot ehole_bot thrusections tool 1 1 whole_top whole_bot bcut p p tool # Add extrusion around the hole plane top_pln 0 0 4.5 circle csmall_outer 23 6.5 3.0 circle csmall_inner 23 6.5 2.0 to3d hole_top_outer csmall_outer top_pln to3d hole_top_inner csmall_inner top_pln mkedge e_hole_top_outer hole_top_outer mkedge e_hole_top_inner hole_top_inner wire w_hole_top_outer e_hole_top_outer wire w_hole_top_inner e_hole_top_inner mkface ftube_outer top_pln w_hole_top_outer mkface ftube_inner top_pln w_hole_top_inner fixshape ftube_outer ftube_outer fixshape ftube_inner ftube_inner prism ptube_outer ftube_outer 0 0 3 prism ptube_inner ftube_inner 0 0 3 bcut ptube ptube_outer ptube_inner bfuse p p ptube # Build elevation "teeths" near the big hole box t1 26 0 0 3 2.5 7 box t2 26 13 0 3 -3 7 bfuse p p t1 bfuse p p t2 # Build elevation "teeths" near the tail box t1 0 0 0 5 3 8 box t2 0 13 0 5 -3 8 bfuse p p t1 bfuse p p t2 # Remove some material from tail "teeths" box blend_box 0 -5 0 5 25 5 trotate blend_box blend_box 0 0 0 0 1 0 -10 ttranslate blend_box blend_box 2.5 0 2.25 bcut p p blend_box # Remove some material from "teeths" near big hole box blend_box 0 -5 0 5 25 5 trotate blend_box blend_box 0 0 0 0 1 0 -9 ttranslate blend_box blend_box 14.5 0 1.5 bcut p p blend_box # Hole at the tail ellipse tail_hole1 0 0 0.75 0.5 plane base_pln 2 6.5 0 to3d tail_hole_3d1 tail_hole1 base_pln mkedge e_tail_hole1 tail_hole_3d1 wire w_tail_hole1 e_tail_hole1 plane base_pln 2 6.5 20 to3d tail_hole_3d2 tail_hole1 base_pln mkedge e_tail_hole2 tail_hole_3d2 wire w_tail_hole2 e_tail_hole2 thrusections tail_tube 1 1 w_tail_hole1 w_tail_hole2 bcut p p tail_tube # Chamfer at tail box blend_box 0 3 0 5 7 5 trotate blend_box blend_box 0 0 0 0 1 0 -5 ttranslate blend_box blend_box 2 0 1.5 bcut p p blend_box # ----------------------------------------------------------------------------- # Extract final solid and simplify it # ----------------------------------------------------------------------------- explode p So unifysamedom result p_1 # Show result pload VISUALIZATION vinit Driver1/Viewer1/View1 vsetcolorbg 200 200 255 vdisplay -dispMode 1 result vfit vaspects result -setFaceBoundaryDraw 1