Hi Jenny,
This tip was given by Geo in an earlier thread, hope it helps you:
If you take the blank weights as 1-lb
#1 as 2-lb
#2 as 3-lb
#3 as 4-lb
and #5 as 5-lb ,you have 40-lbs in weights.
40 lbs divided by 5 pendulums=8 lbs.
Put 8 lbs on each one.

If you still have problems I have a saved game after this puzzle.