Auto Pilot drive unit

[michaelgorie]

1980 Grand Banks 42 Classic - The electronics were old when we purchased the boat two years ago. We installed new Furuno MFD's, Radar, and Autopilot. TZT3 12" upper helm and the TZT3 9" along with the autopilot control unit at the lower helm. The boat has cable steering, and we used the old Wood Freeman autopilot mechanical control box connected to the steering at the upper helm. Not a fan of the Wood Freeman unit and would like to upgrade it. What are the options to connect the Autopilot to the cable steering or rudders? Thank you. Mike

 

[Johnny Electron]

Normally a hydraulic linear actuator (LA), like the link below shows, would be used.
https://www.furunousa.com/en/products/pumpla11-12
The chain drive would just move like a ghost is steering the ship as the LA pushes the rudder back and forth.
I have also seen people with chain drives use systems like the Whitlock drive that has both chain and hydraulic side and it is shifted back and forth via the clutch output of the 700 series pilot. We don't recommend electric actuators as the Navpilot doesn't offer dynamic braking for them.

 

[madmike]

I'm using an electric actuator (Raymarine Type 2 Short) with my Navpilot 711c. Before I purchased it, I didn't see any mention of the non-recommendation for electric actuators. So far the combination seems to be working OK and we've been happy with it. What effect will the lack of dynamic braking create? What should we watch out for?

 

[Johnny Electron]

It can cause oversteering/S'ing. A lot also depends on the hull and side of the rudder. I am glad to hear it is working for your hull. Not everyone finds that the case.