This is the one I made out of PVC pipe.
The sled is made of 1 in. PVC pipe.
The main body consists of 8 in. lengths. (10 pieces, legs and centers)
The center upright is 5 in. tall with two 3 in. lengths connecting it to the center supports.
The front up-slope is 6 in. lengths and the top bar has another two 8 in. lengths.
As you can see in the picture, all the connecting pieces are either 1 in. T or 45 degree angled connectors and the front is a 4-way connector for the chain.
12-8 in. lengths
2-3 in. lengths
2-6 in. lengths
1-5 in. lengths
2-end caps for the rear pieces
PVC glue (this stuff dries REALLY fast so only do one piece at a time)
The chain on mine is ten feet but that is totally personal preference.
$20 dollars in materials
I use it on grass, like I said the glue is really strong and it has held up so far.