Rotating arms on a ship

Hello again! This is another question from the noobmeister. I need to have the arms of my ship rotate around the hull which would in theory simulate gravity (if it was a real ship). Here it is:
I have tried a few tuts but without the desired results. Can anyone point me in the right direction, or maybe some step-by-step action?

make an empty for each of the arm objects at the point around which they need to rotate
select the parts that need to rotate around that empty, and then select the empty and press ctrl-P
then, make sure you are at Frame 1 and press ‘i’ and then select ‘loc rot’
next, go to frame 100 (for example, take a lower number to make it go faster and a higher one to make it go slower) and press ‘n’. you will see a window which shows its positions. then type 360 at rot x, y or z whichever is needed, press enter and then press ‘i’ again with again ‘loc rot’.
next, press RMB a the edge of the window and select split screen. at the left-bottom corner of that window there is a slide menu. from it, select ‘IPO Curve Editor’. you will see the movement of the empty as a curve. select that curve, press TAB and then press ‘v’ to make the line straight. in the IPO window there is a menu called Curve. from it select ‘Extend Mode’ and then ‘Constant’ to make it spin indefinitely. size it along the x-axis to adjust the speed.
repeat this proces for the other set of arms

tried to be as precise as possible
hope it helped


Much thanks!