How Long Must The Ide Cable? Options

[Oldxboxusa]

I have very stupid problems with my Selfmade IDE cable. A friend will make me new cables because at the old one connector is damaged. I have some problems with it:
i think he has try this http://www.xbox-scene.com/articles/multi-drive.php tutorial to made the cable, but which measurement method is in that tutorial?
i have problems with the conversion. How long must the Cable in centimeter? from the start to the end. And between the Connectors?
The Problem is that only the third connector makes trouble with the data transmission (i have tested it in my Computer with a Power Switch for the HDD'S).

Can anyone give me the correct lenght for the Cable?