It took us maybe 4 days. Thats mainly cause were lazy and useless though, we made loads of mistakes and a lot of our tools broke too. You could get it done in a day with some help and if you're organized.
So do I, lol. The landing is only a couple of meters in front of a wall. You've gotta turn as soon as you land, I'm going to hit it at some point and it'll probably look hilarious.
I'd like to say fairly straight forward, but it wasn't lol. It's a 5' and a bit x 8' take off with an 8' radius with a 6' x 6' x 10' landing. The take off was easy to build but the landing was harder work. Considering I have the practical skills of a retard it turned out ok I think.
Well I heard that an 8' radius would be suitable. I drew it on paper to see how it looked before I built it. Then I just used an 8' piece of wood with a nail in to draw a smooth transition.
You could get it done in a day with some help and if you're organized.