One more thing on fiberglass spinners...I consider them to be safer than aluminum ones. If the spinner comes off on climb out, the prop is much less likely to suffer damage if it hits a composite spinner than if it hits an aluminum one. And as http://home.hiwaay.net/~langford/spinner/ mentions, the store bought aluminum spinner was badly out of balance, whereas my homemade one is as close to perfectly balanced as I can ascertain.
Mark Langford N56ML "at" hiwaay.net website at http://www.N56ML.com