Hi gparadox! Welcome to the forums!
Here's what I posted on some other threads- hope it helps
1. pick two numbers that are next to each other, any where on the outer wheel
for example- 5 and 9
2. add them together = 14
3. find that number on the next wheel and rotate it around so the lines around the 14 match up with the lines around the 5 and 9
4. if that number (14) is not on the wheel, forget the 5. add the 9 with the number next to it, then rotate the wheel so they match up.
5. check that all the other pairs of numbers add up to the number from the 2nd wheel that's by them
6. do not move the second wheel
7. now repeat the process, choosing 2 numbers from the second wheel and rotate the third wheel until the sums are equal.
Continue until you reach the center. If you are sure the sums are correct- make sure all the lines between the numbers are lined up.
I hope this helps