to make it hollow.
        
        
          I use Shapeways
        
        
          “Frosted Ultra
        
        
          Detail” resin that
        
        
          requires a minimum
        
        
          wall thickness of
        
        
          0.5 mm, about 2”
        
        
          in HO scale. In this
        
        
          case it’s easy. The
        
        
          edges of the top
        
        
          recessed rectangle
        
        
          are 2” inboard from
        
        
          the side recesses.
        
        
          The overall height
        
        
          of the crate is 36”
        
        
          so the top and bot-
        
        
          tom recesses are 32” apart. So just push the top recess down
        
        
          another 30”.
        
        
          Let’s put a couple of 2x4s on the bottom to stabilize the sides
        
        
          and so a fork lift can get its forks under it. Construct a 2x48x4
        
        
          box away from the crate. Select the entire 2x4 by making a
        
        
          rectangle around it and with the Move tool, pick a corner and
        
        
          move it so “On Edge” appears. There are a number of position-
        
        
          ing aids available. They automatically appear when the align-
        
        
          ment is close. I tried to capture them, but they do not appear
        
        
          in the screen shots. The select tool is a bit different; once the
        
        
          part is in the right location hold down the shift key to lock it in
        
        
          place until you pick another tool. Otherwise the part just keeps
        
        
          following the Move tool. Use the Select tool to select the 2x4
        
        
          and copy it using “<ctrl> c”. Move it around until “On Edge”
        
        
          appears (make sure it’s the right edge) and release it. You want
        
        
          something that looks like [11].
        
        
          10
        
        
          10. A hollow crate.