I have a global avance im starting to build tonight. I saw that there is no conversion to make the main gear NON retractable. So my question is, what are my limitations for servos. can i use a standard or does it have to be, high torque, ball bearing, metal gear and slower than a standard?? I do believe it needs to be low profile, but if you have good knowledge of the other specifics please reply asap!! thanks.