Autopilot direct drive unit type I

The Jefa direct drive type 1 is an extremely strong and compact autopilot drive and much more efficient than existing hydraulic and electro-mechanical autopilot drive units. 

It's much stronger than a human being (the max. output torque of 150 KgM is equivalent to 150 Kg force on the end of a 1 meter steering tiller) and is build for 24 hours per day continuous operation with a total weight of only 12 Kgs. The combination of the flat wound (pancake) electric motor with the ultra efficient planetary and spur gearbox results in an extremely efficient drive unit to keep the battery charging time to the minimum. The drive can be used on small boats from 30 to 45 foot l.o.a. (or up to 150 Kgm rudder torque) equipped with a mechanical steering system that can be back driven.
The direct drive drives the rudder via a draglink and the existing tiller arm or quadrant or via an independent tiller arm. (see illustration)

The Jefa 150 KgM direct drive type I is very compact with a length of 345 mm, a width of 164 mm and a height of 185 mm. As space is always a problem on sailing yachts, the direct drive unit can be mounted as close as 250 mm from the rudderstock even upside down.

This performance table shows the relation between the consumed power and the output power. The red line shows the output torque against the needed amperage at midships rudder and the blue line shows the output torque against the needed amperage at full rudder. The green line shows the hard over time (time to travel 72° of rudder travel) of the drive relative to the output torque. Also visible is the strength of the drive unit related to man power. The unit is much stronger than a human being and can last much longer but one should note that when the unit is operated in the red zone, something is wrong with the trim of the boats and the sails should be adjusted to achieve lower rudder torques. The above table shows that the Jefa direct drive type I will steer the yacht even in the worst possible conditions. As the drive will mostly operate in the left green zone and will not continuously rotate, the average power consumption on 12 volts is 2 amps.