Building the hopper...
The hopper is another disposable ball point pen with the ballpoint pen and ink well assembly taken out. I used the cap to prevent ammo from bouncing out.
Building and attaching bump switch timer to the barrel...
1. Take a large paperclip and bend the small "U" away from the large "U" into what looks like a number 8.
2. Bend the paperclip into an "L" shape as pictured.
3. Tape the small "U" to the top of our barrel with your favorite tape of choice. Masking tape works well for this.
Building the hopper holder...
2. Than using needle nose pliers bend into a u shape. Leave plenty of length on the uprights of your "U". They will stick in to the corrugated cardboard and allow us to position the hopper right where it needs to be. The extra length also allows it to be positioned far enough away so that the barrel will not swing into our hopper holder.
3. Take another large paperclip and straighten.
4. Using the needle nose pliers wrap one end around the corner of the "U" we just made. Wrap enough time so that the two paperclips will not shift relative to each other.
5. Bend the paperclip we just wrapped around our "U" into an "L" shape.
6. Take another large paperclip and straighten.
7. Wrap around the "L" we just made to extend the length of the "L" and give you enough to wrap around the hopper enough times to secure it tightly.