up position
The pop up unit on my Mac is also held up by two post that are set into angled supports located on top of the dog house or deck top in front of the pop top. I replaced the originals with a couple of pieces of conduit, with one end on each flattened and a hole drilled into the flat end. This allowed for the bolts set into the pop top to pass through the holes, and wing nuts attached so as to lock the whole thing into place. When lowered, the same bolts lock to the deck top and secure the pop top in the down position with the same wing nuts!