I like your ammeter bit Alex!
@Bean13, if stepping up the power supply doesn't cure it, you can use a proto bit to give the servo a second power supply to provide power directly to the servo.
Here is how to hook it up:
In the above picture, the number bit on the left represents your dimmer, the number bit on the right represents the servo, and the second power supply is the black (ground) and red (+5 volts) wires attached to the proto bit from the top of the picture. These wires come from a wire bit that was cut in half , attached to (in this case) a usb power bit. The 5 volt supply MUST be regulated 5 volts (or your bits may become damaged.)
Another option is to swap out the actual servo motor on the bit for a more powerful motor. It unplugs from the JST connector. The connector on the wire is the same as the one on HiTek and Parallax motors (RadioShack, Fry's, etc.) except it's turned around. The openings face outward on the replacement motor. Don't worry, if you put it in wrong, it just won't work, so turn it around.