The feed hopper is looking great! Nice work.
I also used a tamiya vibration motor on my feed chute. Controlled by a radio channel so I have complete control of what speed to use. There's another very cheap way to have very good speed control. I like it so much, I bought a few and use for testing stuff and in projects.
http://www.ebay.ca/itm/New-DC-6V-90V...gAAOSwWTRWwppP