I took the Ky Journeyman’s about 8 years ago and I couldn’t believe how many failed the pratical.
There are 3 different tests, both on the written, and the pratical. So don’t expect if you failed one side of the test, that the same copper jig will be there when you return.
On the jig, they sometimes give you the overall dimension, sometimes from end to center. What you need to do is take your time, and assemble the jig partially with your known dimensions.
If they give you a dimension from the center of one 45 to say one end or the other, you will need to know the length of the pipe that goes down to the next fitting.
It is always easier to show than explain, but the trial and error idea was the best way.
The jigs are slightly loose where you have to put the piping into.
“Your best interest is secured by making the right decisions the first time.”