[Joe Ross]

In the past, a servo has been considered a motor and so a continuous turn modification would be illegal per <R38>. Since a servo is simply a motor with feedback, it should be. However, since past rules and interpretations do not apply to this year's rules, I searched the rules again for direction and found the following alternate interpretation.

<R91> says that all motors must be driven by a speed controller or a spike. Therefore, a servo isn't a motor, because it doesn't have to be driven by a speed controller or spike.

I've asked about <R91> on the FIRST Q/A. Personally, I wouldn't make the modification until the question is answered.

Edit: See Ken's post below for the official answer.