Some here : http://206.145.80.239/zbc/showpost.php?p=308049&postcount=46
http://206.145.80.239/zbc/showpost.php?p=326686&postcount=238


and my little last :)

3 curves for a sweep :)
Remark that rail 2 & 3 don't need to be connected to curve 1 !