Using 7/16th inch brass, I cored out one of those Giant Erasers from the Dollar Store. Snicker's used a 5/16th inch hole punch for his eraser (we used different erasers).
Each core is as thick as the eraser which is 1.75cm (0.69"). Each core can be sliced into 4 equal pieces. Each at approximately, 0.44cm (0.17"). Each eraser can produce 96 of these dart heads.
I counter sunk and hot glued the dart heads into the foam.
*Optional - I use straw inserts in my darts to help with rigidity. I believe they improve accuracy and range.
Although they do require a bit of elbow grease, they only work out to be about $0.011 per dart head. The total average weight of each of these darts is between 1.1g and 1.2g.
And of course, to answer the question most of you will have; yes, they are hopperable.
Using 7/16th inch brass to create the cores and counter sinking the dart heads into the foam really help with this. They perform brilliantly.
I don't have a drill press but I'm working on mechanizing the coring process.
*Edit - Upon request, a little more detail for the process.
I tend to use the straw insert in Stock Nerf and Buzz Bee foam but the same can be applied to solid rod foam as well. No dremel or drill is required. Just some hand eye co-ordination and a bit of practice.
I use a length of straw just shy of the full length of the foam blank(s).
By centering the straw at one end of the blank I simply twist the straw into the foam. Firm pressure as you twist will eventually bite into the foam. Once it has started to core, it will penetrate much easier as long as you keep twisting. It literally takes seconds once you've got the knack.
Above, you can see where I've marked it off to cut.
Pulling the straw out a bit, I cut.
Next I added a small ring of hot glue at the end of the straw.
Next I quickly pushed the straw in. Note that I left the foam inside the straw.
Creating the 'pocket' for the eraser is pretty easy. Using the tip of my hotglue gun, I simply melted away the necessary foam, like so. It's easier to roll the blank around the tip of the hot glue gun than it is to maneuver the hot glue gun around the foam.
The process is the same for my stock foam blanks.
Next I add a little hotglue to create a thin film to close up the hollow in the straw.
If you don't want to use the straw insert just skip to this step:
Let the whole thing cool down as you move on.
As you can see below, the eraser pads you've created sit nicely inside the pocket.
Burn a tiny hole into one side of the eraser pad before adding a generous dab of hot glue. This allows the hot glue and the eraser material to have a better bond. While it's still hot, insert the dart head into the pocket of the foam blank. While the glue is still hot, you'll have a few seconds to squish it around to set in the correct position. If you've added just the right amount of hot glue, it will seep up the sides of the dart head where you can further adhere the foam along the sides of the eraser. The deeper the pocket , the better for hopper feeding.
As you can see above, although I know both will feed in my hopper set up, the one on the right is more ideal.
Since the eraser is the weight and the padding weight distribution is properly set forward.
**Edit - short video of them being fired out of a hopper from a lightly modded TS.
Edited by makeitgo, 08 October 2012 - 09:42 PM.