In this instructable, I will guide you through my process of making some batarangs. I intended this as more of a guide than a step by step instruction. There are parts that I intentionally left out some details because the parts or method my different for everyone. There also may be some parts I unintentionally left out. Please let me know if so.

WARNING: This instructable uses power tools (namely a power drill and dremel with cutting wheels). Improper use of these tools can cause injury. Please be careful and use the proper safety precautions. Also, the resulting batarangs are sharp. If they aren't sharp, they have a jagged edge and that's even more dangerous than a sharp edge imo. Please refrain from throwing these things at anything other than a cardboard box because they will stick in and they will hurt. I ACCEPT NO RESPONSIBILITY FOR YOU HURTING YOURSELF, ANYONE ELSE, ANY PETS/ANIMALS, ANYONE'S TOOLS, OR ANY OTHER MATERIAL POSSESSION. Please be safe. Also, try to avoid throwing these at trees. They might get pissed and start throwing them back. /enddisclaimer

Ok this is my first instructable so please leave comments on anything that might make this more clear or otherwise a better instructable.

I based this design off of spookylean's instructable located here. The major difference is mine require less work and are probably more durable based on the different material used so if you screw up a batarang you are less invested time and money wise.

Step 1: Tools and Materials

As far as tools go, I only used a few. Tools I need:
     A power drill with a few various sized drill bits
     A dremel with some cutting wheel attachments (went through a lot of them) and maybe a grinding wheel attachment if you want to smooth down the finished product

Other materials I used:
     Dead CD drive (for use as scrap metal. May be substituted for anything else that can provide scrap metal) (free, already had)
     Two machine screws (one for each batarang), two hex nuts, and a lock nut (total cost was about $.50 with tax. I don't know exact cost as I bought other things and they are the only things I had to buy for this project)
     Screwdrivers to take apart cd drive and later assemble batarangs
     Prototype batarang made from a dvd (the hinge is a staple if anyone is wondering) (late night project)
     A permanant marker to trace the template onto the cd drive or a pencil. The marker is easier to see though
     old phone book so I wouldn't drill holes in my desk/floor
     Cardboard box to act as a target for finished batarangs

Note on screws, drill bits, and nuts: The size of them all depend what you have available. If you only have one size drill bit, you should probably buy screws that would fit the hole produced by that drill bit and of course nuts that would fit said screw(s). Also you can use whatever nuts you prefer. I used different kinds as an experiment. So far my results are inconclusive.

Step 2: Prepare Scrap Metal

You may use anything that you can scrap some metal off of, but I happened to have a dead cd drive laying around so I used that. You are going to want to take it apart so you can handle the top a bit easier. This particular model had five screws and rubber springs holding it together. All you want is the large, flat, metal piece on top with the label (which you may want to remove now).

Step 3: Trace Pattern on to Scrap Metal

At this point you should decide if you want to make a fold-able one or just a straight one. Well I provided the template for both. On the straight one you can ignore the circle and dot in the middle. On the fold-able one, you will want to trace and cut it out of metal twice (or you'll end up with only one half of the device).

Print out the template (or just wing it) so you can trace it out on the metal. I went from template to dvd to metal but you can skip the dvd part if think you will be satisfied with the size/shape. I was able to make three different batarangs from the amount of metal I had, one straight, two fold-able. You only need one screw and nut for each fold-able.

The second image is the same as the first only with transparency (which this site doesn't appear to handle too well). Just hover over the big image and click the little italic i in the top left corner of the image to see the original.

Step 4: Start Cutting!

Sorry, I have no pictures of this part. (I couldn't think of a safe way to take a picture of me while cutting. The phone I used for pictures didn't have a timer nor could it be mounted to a tripod.)

DO: Wear gloves, safety glasses (or sunglasses), and a mask.
REASONS: The gloves protect your hands from the cutting disks that turn into shrapnel and from the heat. Cutting the metal causes a lot of friction and therefor heat. You can very easily burn yourself while just holding on to the piece of metal that is being cut. The disintegrating wheels and metal make a lot of dust. You don't want to breathe this. And the glasses. Oh my gods the glasses. These are the most important. Most of the cutting wheel shrapnel heads towards your face. If you use a dremel and cutting wheel attachments, you MUST have glasses. I had so many pieces of shrapnel bounce off of the glasses that would have otherwise hit my eyes. Please try to be smart and not end up in the emergency room. I will have no sympathy for those who do (hopefully no one).

DON'T: Cut near anything flammable. The fiberglass cutting wheels put out a lot of sparks. Try to not aim those at yourself either.

This is also the time to debur and smooth any rough edges. You may also sharpen some edges if you please. If you are throwing them all they need are the points to stick into something but I'm sure a slightly pointed edge may help.

I spent about 3~4 hours cutting and grinding to get the next part.

Step 5: Adding Your Hinge

If you made a fold-able type then you are probably going to want to make a hinge. If not then you may just skip this step entirely. I spent a few hours thinking about how to accurately measure the center of the circle part with the tools I had on hand since I used the template more as a guideline than an actual cutting line and since i grinded off my original marks before I drilled any holes. I started using a flat edge and tracing lines and didn't get anywhere fast. Then it occurred to me that a cd hole was about the same size as the original circle. I could use that and very easily eyeball a center spot. I did that and marked the result with a pencil.

Once you have the center hole marked for the hinge, go ahead and place the 'wings' on top of a phone book (no pictures of this part either for the same reason as earlier) and start SLOW until the bit stops dancing around and settles in the right spot. As far as the right size bit (I used 1/8) I just found the largest bit that still fit in the nut. As soon as your hole is drilled, pick up the piece and rotate it around the spinning bit to get rid of all of the metal burs left over and make the hole large enough for the machine screw to fit. As soon as that part is done just put your screw through and tighten the lock nut or hex nut duo until you can spin the batarang around with enough resistance so that it will hold it's shape.

If your screws are long, you may want to break the dremel out again and cut off the extra screw (make sure the nut is on because you may mess up the threads on the screw and it could be difficult to get the nut back on)

Step 6: All Done!

All finished! At this point you can add any finish you want (well you'll probably have to take apart your fold-able batarang). You can paint them or just grind them and leave them like that.

They are best suited for props and throwing short distances into cardboard. DO NOT THROW THESE BATARANGS (OR ANYTHING ELSE) AT SOMETHING YOU DON'T WANT TO BREAK OR SOMEONE OR ANY PET/ANIMAL.

Enjoy your new home made batarangs and geek points among your friends!