The parts are quite simple. For one obstacle you need.
(3) five-foot lengths of 1/2" PVC pipe
(6) S-hooks (smallest size available)
(6) Curtain Rings
(3) 5' x 7' tarps
The tarps I bought from eBay at $33 shipped for a case of 24.
The S-hooks I bought at Home Depot. They come in a package of 4 for $1.23, but in hindsight I probably could have used just curtain rings.
The curtain rings I bought at Target, they come in a package of 12 for $1
The pipe I bought from Mcmaster, but Home Depot has them at the same price ($2 ea)
That makes the total cost of each obstacle $12.45
1. To set one up you simply use a fence post driver or sledgehammer to sink the pipe 4 or 5 inches into the ground.
2. Then repeat with the two other lengths of pipe spaced 7' apart in an equilateral triangle, or in a row to make a fence.
3. Use S-hooks to hold the tap in the top of the pipe.
4. And two curtain rings total to hold the middle and bottom of both tarp that meet up with that pipe.
In the event that someone physically plows into an obstacle the s-hooks pop out of the top of the pipe and the tarp falls to the ground. The obstacles I've set up in my back yard withstood 20 mph winds but I have no estimate as to how high of a wind they can hold up to. You don't have to worry about them falling over under a light breeze or mild gusts.
To make taller obstacles all you have to do is use a cross coupler join two 5-foot lengths of pipe together after driving the lower pipes 6 or 7 inches into the ground. The lower tarp joints to the open end of the cross coupler using s-hooks and the upper tarp does the same in the upper pipe.
Making other shapes is entirely up to the person setting up the obstacles. I simply went with the shapes that provided the highest stability against the wind and provided cover from multiple directions. The triangle also meant that if someone was hiding behind it the sunlight hitting from behind them wouldn't create a visible silhouette.
If you want to discourage people from climbing inside of these you can simply use string to tie the center loops of the tarps together.
Edited by CaptainSlug, 17 June 2007 - 09:17 AM.