I used the Sonic Tronic hinges that Les made mention of. Getting them in the right location is a challenge.
If your not concerned about scale operation, you could hinge the door at the bottom so it flops down. If it's hiding switches, etc., it really won't matter that much.
Paul

Link to Sonic Tronic [link=http://sonictronics.com/xcart/home.php?cat=321]http://sonictronics.com/xcart/home.php?cat=321[/link]