you want to be using relative location not world (it makes things much easier). show us your script so we can see what you did so i can better help you fix it.
as for the other part of your comment it seems like you mean theres a set pattern to the spikes in which case you need to script when they move. theres many ways to do this but im sure someone else out there would have a better idea than I (the solutions i think up for it arent very elegant)