... lines are construction lines. 2983_041946_070000001.gif Now we drag the seat on to the base and snap it to the intersection of the center-line and the rail. 2983_041946_070000002.gif The seat is actually a block that can be used repeatedly in any model. If a block is edited any changes will be immediately replicated in all instances of the block. (And blocks can be nested. For example, a chair screw can be a block and if I edit it all the screws in a turnout model will immediately reflect the changes.) 2983_041946_070000003.gif We've now rotated the seat (4 degrees this time.) Obviously it's much too long. That's where those extra construction lines that are inset from the sides of the base come in. We slice the seat along those lines and delete the overhanging bits to produce this. 2983_041946_070000004.gif Another view. 2983_041947_480000001.gif Now drag the jaws block into position. 2983_041947_480000002.gif And in plan after rotation. 2983_041947_480000003.gif It needs to be trimmed too. A slice might be OK but there should be a bit of a drafting angle, so rather than ...