Heres a good thread on a homemade hide thats a bit more on the heavy side..
http://ball-pythons.net/forums/showthread.php?t=77863

But truthfully unless you have an extremely heavy hide, the snake WILL move it to it's liking... Unless you want to glue the hide to the enclosure? But i don't see how sanitary that would be when it comes to cleaning... But if your temperatures are correct (Correct hot spot temperature, and ambient temperature), your snake will have no chance of getting too cold & dying if they move their hide..

~Brandon