incubator help

[trapper]

i bought a homemade cabinet style incubator from a friend. the concept is excellent if you are a veteren, however i am a novice that is hooked. looking for a book,site, etc to help figure out how everthing needs to be set up to be efficient. my main concern is my racks keep rotating too far. i lost a dozen eggs on the floor when my son and opened the door to fill the water tray. don't want that to happen anymore. any help would be appreciated!!!

 

[rooster-red]

Since it is homade can you post some detailed pics?
It might be a design flaw, but we can't tell without pics.