Step 1: The Tools
1x drawer slide
2-3x belts or Velcro straps
Dremel metal cutter
Step 2: Some Assembly Required
Cut the drawer slide to where it fits comfortably on your forearm. Make sure to make a tab to stop the slide from falling out the back end.
Use the hammer to gently tap the sides of the drawer slide tight to the inner drawer slide( this locks the "blade" in place). Make sure it's not too tight.
Test it out to make sure it slide the way you want.
Lastly, either glue with a VERY strong epoxy or use a strap made of duck tape to make your arm straps. Now you can decorate it any way you want.
Step 3: A Final Note
This project may cost between 30 and 70 dollars. But you can make matching sets by doubling the recipe, if you get what I mean. This is my first instructable so don't be too harsh, but constructive criticism is very welcome.