Copyright  Goodheart-Willcox  Co.,  Inc.  Chapter  8  Creating  and  Working  with  Solid  Model  Features  193  In  Figure  8-17A,  the  bottom  shelf  has  been  created  as  an  extruded  solid  from  an  ellipse.  The  shelf  is  .375″  thick  and  is  centered  on  the  UCS  origin.  The  underside  of  the  shelf  rests  on  the  XY  plane.  A  second  ellipse  is  drawn  on  the  XY  plane  and  rests  on  the  underside  of  the  shelf.  This  ellipse  serves  as  the  path  for  the  3D  path  array.  A  construc-  tion  cylinder  has  also  been  created  with  its  base  resting  on  the  XY  plane.  The  construc-  tion  cylinder  is  2″  in  diameter  and  2″  in  height,  the  dimensions  of  the  table  feet.  The  construction  cylinder  is  the  item  to  be  arrayed.  During  the  operation,  the  base  point  of  the  array  is  specifi  ed  as  the  top  center  point  of  the  construction  cylinder.  This  aligns  the  top  of  the  cylinder  with  the  start  of  the  path.  Since  the  path  is  an  ellipse,  AutoCAD  defi  nes  the  start  of  the  path  as  one  of  the  quadrant  points  on  the  major  axis.  When  the  base  point  is  selected,  the  cylinder  is  then  aligned  with  the  quadrant  point.  This  is  a  suffi  cient  start  point  for  the  array.  After  selecting  the  ARRAYPATH  command,  the  construction  cylinder  is  selected  as  the  item  to  array  and  the  construction  ellipse  is  selected  as  the  path.  The  command  sequence  continues  as  follows.  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  AS↵  Create  associative  array  [Yes/No]  Yes:  N↵  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  M↵  Enter  path  method  [Divide/Measure]  Measure:  D↵  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  I↵  Enter  number  of  items  along  path  or  [Expression]  current:  4↵  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  B↵  Specify  base  point  or  [Key  point]  end  of  path  curve:  (Use  the  Center  object  snap  to  pick  the  center  of  the  top  of  the  construction  cylinder)  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  L↵  Enter  the  number  of  levels  or  [Expression]  1:  2↵  Specify  the  distance  between  levels  or  [Total/Expression]  current:  2-3/8"↵  Select  grip  to  edit  array  or  [ASsociative/Method/Base  point/Tangent  direction/Items/  Rows/Levels/Align  items/Z  direction/eXit]  eXit:  ↵  The  resulting  array  is  shown  in  Figure  8-17B.  The  four  cylinders  on  each  level  of  the  array  are  evenly  divided  along  the  elliptical  path.  Because  a  non-associative  array  was  created,  the  cylinders  can  be  selected  and  edited  as  independent  objects.  Notice  that  the  four  cylinders  in  the  second  level  of  the  array  rest  on  the  top  of  the  shelf  at  the  correct  position  along  the  Z  axis.  In  Figure  8-17C,  the  four  cylinders  in  the  second  level  of  the  array  have  been  changed  to  1″  in  diameter  and  14″  in  height  using  the  Properties  palette.  The  edited  cylinders  form  the  table  supports.  A  shaded  version  of  the  completed  table  is  shown  in  Figure  8-17D  after  copying  the  shelf  along  the  Z  axis  to  create  the  top.  NOTE  NOTE  Grips  are  available  for  editing  an  associative  array  after  the  array  is  created.  Hover  over  a  grip  or  pick  on  a  grip  to  edit  the  array.  If  you  pick  a  grip  and  more  than  one  option  is  available,  use  the  [Ctrl]  key  to  cycle  through  the  options.