Years ago I wanted to make this project, and I decided to finally order the stuff off amazon in order to make it. I have most everything except the extra wire (which I will get) but when I look at the servos that I have I realize that they won't work with my 9 volt battery connector.
The battery connectors I have only have the positive and negative cables going out. The ones for the servos have negative, positive, and a ground cable. Is there any way around this? Would simply cutting the servo connector off removing the ground allow it to work? Because I did stick the 9 volt battery cables into the connector I heard a faint buzz for a split second but the motor did not start.