OK, this Instructable is based on a friend's design. He told me that you could easily make a throwing star in about ten minutes by cutting up an old circ saw blade, so we decided to try it at the shop. It is indeed most awesome. *** If you really like this build and think it could help you survive a zombie apocalypse, please vote for it in the Apocalypse Preparedness Contest in the upper right corner!!! *** But, before I can tell you anything else, you have to agree to these rules or else please stop reading.
1) You can never throw these things at any living creature or let any of your friends do it. They are for fun only and should be considered comparable to throwing darts or knives (which you should also never throw at living things).
2) It is illegal to have these things in some countries. Please do NOT make them if it is not legal where you are.
3) I cannot be responsible for anything you do that is irresponsible and/or results in you injuring yourself or others (refer to rules #1 and #2). I know they are fun but please use your head and remember that they can be as dangerous as throwing knives or darts, so just don't throw them at people. Or animals.
OK! If you are still reading then you are a good and upstanding citizen who obeys the law and promises not to be a dummy. If you plan on breaking any of the rules then I recommend that you instead make a giant plushy play set.
So, I know there are professional ninjas out there who will say things like "duh, they're not called ninja stars" and then go on to correct me, but please be advised that I have read the wiki page and now know nearly as much as you do and yet I'm still calling them ninja stars. But I digress. Let's continue.
Step 1: Make Yourself a Star
So, here's how I did it.
I took an old saw blade and screwed it down to a plank of wood, using a washer in the center.
I then printed out a ninja star outline (I think this was the image I used) and spray glued it to the blade. I slowly and carefully drilled out 1/2" holes where the rounded areas are and then used a thin cutting disc on an angle grinder to cut out the sharp ends.
From here it was off to the bench-top grinder. I sharpened the edges slightly by carefully holding the star on a ~30 degree angle and lightly bringing it to the grinding wheel. You should always wear safety gloves and glasses and exercise extreme caution with all of these tools.
Finally I cleaned up the edges with a wire cup in the grinder. This part can go terribly wrong if the grinder catches in the star - only use this tool if you are already familiar with it
Step 2: Bet Your Mates for Money
Only do this if betting is legal where you are. Here my good friend Steve and I pinned large bills to a target (plywood) and took turns throwing from a distance of about thirty feet. If you nail a bill you may keep it. That is the rule of this game. So you see, rules can be good for you and throwing darts can be a lot of fun if done responsibly.
PS, none of these rules apply to the undead. Use any means at your disposal to rid yourself of a zombie scourge.
Let me know if you have any comments or questions!