I am trying to do my first home project. Basically it is going to dispense (upon button press) an exact serving of whatever food you want. I have most of the programming and wiring done. The next thing I have to do is figure out how to turn the knob on the dispenser using a motor. I have this motor (http://i.imgur.com/Kk0OLRQ.jpg) . I am willing to get another motor if I need to. Here are pictures of the apparatus, and the knob I need to turn.
http://i.imgur.com/BXOFSKh.jpg [3]
http://i.imgur.com/1ToVv3H.jpg [4]
http://i.imgur.com/7cydjXK.jpg [5]
I have a kitchen scale under the dispenser, and I want it to stop dispensing when the scale reads 28g (for example).
The knob is glued onto the axle, which sticks into the paddles on the inside. For now, I am thinking that I should remove the knob, and attach the motor to the axle, and basically just bypassing a knob. I would need a different motor, but I am not sure exactly which one to use. I am thinking about a servo motor.
Any advice is greatly appreciated.