OK. As you create the 1st set of spikes, dupe them, and rotate the dupes 36deg. Select all and group again. Rotate these 72 deg. Ungroup, and select the last pair. Dupe these and rotate another 36deg and your there! I have to admit to being a dummy with modeling, so I haven't figured out the array function either! (Maybe it's easier, but this way I know!) :>