Non-blocking build.
Press 6 ( big box hotkey ) or get a click the big box in the summoning panel, now press the space bar to make it a ghost item.
Now get a little board, press space, now press b, and put it in the ghost box.
Now get a big board, rotate it (press x) until it's in the right position, then press c 2 times.
If this build is unstable, get a little board, rotate it with x until it's in the correct position, then press space bar, and then press b and summon it in the middle of the big board.
Normal & safest build
Just put a little board with b and space bar, big board with rotation and c 2 times.
-Thecoolpool, administrator.