Servo OptionsTippecanoe Boats
The HS645 Ultra-Torque servo increases the torque compared to the HS422 servo. However, the HS645 is an analog servo and it can be upgraded further to a digital servo, either the D645MW or HS7955.
The digital ultra torque servos are the same outside dimensions as the standard analog servos, but the digital servos carry a big punch. In conditions where it might be difficult to pull the sails in with the analog HS645 ultra torque servo and might even require a momentary partial luff, the D645MW servo yanks the sails right in tight. The HS645 analog servo is rated at 133 oz. inches of torque at 6 volts, the D645MW digital servo is rated at 168 oz. inches of torque at 6 volts, and the HS7955 digital servo is rated at a huge 333 oz. inches of torque! This 7955 top of the line servo has twice as much power as you will ever need and it is definitely over the top. There isn't even a flicker of hesitation no matter what the wind is doing at the moment. One drawback is that the standard sail arms aren't necessarily strong enough for all of this extra torque with the 7955 servo, so an upgraded stainless steel and aluminum sail arm must be installed as well.
One important aspect of these digital servos is that they can be programmed for up to 120 degrees of swing instead of the standard 90 degrees of arc. Any digital servo you get from Tippecanoe Boats will be already programmed for the maximum swing. Along with the double throw sheeting system included in this kit, the extra swing on the servo gets your sails out almost perpendicular to the center line and pulls the main sail in to a centered position and the jib in to create a perfect slot.