I'm partial to a servo that doesn't exist anymore for t/b and steering for that matter, hitec 985MG. They sell a similar one now that's digital, the
HS-7985MG. Same specs as the old one, but I'm guessing it's holding power is better since it's digital, they have a much higher clock rate than analog, so they fight harder to stay where you point them.
For a decent budget servo, the
savox 0231MG isn't bad, or spend about the same as the hitec and get a high torque savox like the
SW120-SG. That has near the same speed as the hitec, but 100oz more torque. You need to get a
glitch buster cap to go with either savox as they are power hogs. The cap plugs into an open port on the receiver, or into a Y cable on the receiver to supply instant current to help avoid a brown out when the servo first moves. I'd suggest you only run any of the 3 servos with a proper hump pack or lipo receiver pack. Standard AA's just can't deliver the current needed.
I'm only suggesting waterproof/water resistant servos. I don't buy anything else anymore. Not worth the hassle with how I wash my rigs or where I drive them. Waterproof is a must.
