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It took me about six days to design it, to haul the materials from the hardware store and to build it. They weren't complete days because my lunch breaks were longer than the usual 30 minutes. But driving the poles into the ground was hard work. About 20 were 1.5m tall not including the 50 cm long anchor. Five were 2m tall. I had to stack up a couple of car tires to be able to reach the top with the sledge hammer and to deliver enough force to the top of the pole with the hammer. It took about 45 minutes to finish sinking the anchors of the door frame into the ground. I had to be careful because the two sides of the frame weren't perfectly aligned and the thing started gradually to fall apart. The door frame had to be assembled before driving the anchors into the ground because controlling the direction in which they sink in would've been impossible otherwise. I'm there was only about 3 cm to go before it was complete. It's good enough.

I had no help from anyone. I'm glad I managed to finish it.