I'm a complete newbie trying to build a simple robot that dispenses candy (M&M, skittles, etc). However, since I'm not familiar with the field, I'm having a hard time googling because I don't know the correct terms to search for. I'm looking for a piece to build a robotic 'trap door' of sorts that will open for a specified amount of time to release candy. What parts can I use and what is are called? I've tried robotic lever, robotic door, etc with no luck.
Your mechanism will depend on the type of dispenser you want. Like if its gravity feed or not. I will assume it is, so I make this sketch to give you some idea:
The hole size will depend on how many candy you want to dispense at each stroke. (Of course its related to the candy size). The electro-mechanical actuator can be a crankshaft one, a solenoid, a linear motor, and goes on.
You can use a vibrator attached to the cup if the candy tends to get stuck.
There are two good search terms that come to mind. The first one is a "candy machine mechansim", or "dispenser mechanism" (e.g. http://www.woodworkingformeremortals.com/2012/10/make-candy-dispenser.html). There are several models of off-the-shelf pet food dispensers and cereal dispensers that use this method.
The second term would be a screw conveyor (a.k.a. "auger dispenser"/"food auger"/"grain auger"), which describes a more continuous-flow version of what you are describing.
This type of dispenser controls the volume that is delivered by rotating the auger by a fixed amount, not by dumping a fixed-size container.