power requirements for large scale servo

[justin060473]

i have a custom built 1/8th electric monster truck which could do with better steering. a 12kg/cm servo in at the moment is almost good enough but not quite. i use this servo in the E-maxx and Hyper 7 buggy and it is great on them. i plan to cut the aluminium chassis on the bigger truck to fit a servo such that is used in 1/5th scale FG marder type trucks, as these have around 20-25kg/cm torque. here comes the crunch question; how much current do these big servos take? is a 3A cont. 5A max UBEC going to suffice or will it have to be a good quality 5 cell RX pack????????

[The Dane]

Physics:

Potential energy E=MxGxH
M=mass in kg
G=gravity (9.82m/s2)
H= height in meters

To lift 24kg 1 cm in 1 second You need 24kg x 9.82m/s2 x 0.01meters = 2.36 joules

Watts = joules/second

So we used 2.36 Watts to lift the 24kg

Effenciency of a servo? 50%

To make it simple, lets just say 5Watts was used to translate that to electricity is simple.
P=UxI
5W=5Vx1A

So the current in that second was 1A