autopilot

[gilles]

My freind launched this summer his Brewer 43 cutter after 3 years on this project.This sailboat has a hydraulic steering, he want to add a autopilot and was asking my opinion about installing a Raytheon 4000+ or a Simrad WP30 instead of a much more expensive hydraulic pilot.The boat weight is 24,000 pounds, but the actual hydraulic stering is very easy to turn even in hard weather, my own Hunter 28.5 (wheel and cable steering) need more strength than the hydraulic on his 43 ft sailboat.We were trying to figure: why, if the autopilot can steer my hunter, why would'nt be able to steer the big boat in installing the Simrad or the Raytheon directly on the steering wheel. The small pilot will turn the steering, the wheel will actionate the pump, the oil pressure the cylinder and the cylinder the rudder ? That is the few thousand $$ question????So I would like to know if one of you had ever experienced something similar, if so, what were the results? If you never had this type of dilema but you have experience in the domain we will be pleased to receive your opinion.Thanks a lot.

 

[Derek Rowell]

ST4000 on 22,000 lb boat...

I have a RayMarine ST4000+ MkII on my 22000lb Pearson 422. I rationalized it similarly to you, namely that the boat was very light steering without much weather helm, and that I wanted to use it mainly under power on those long hot trips up the bay in light air. It has worked great under those conditions. However it seems to "lose it" when the wind pipes up to 20+ knots. I don't know why. The steering is not overworked, it just doesn't hold the heading. I am still looking into it, playing with the rudder gain etc, and now questionning whether the compass gimball is being thrown out when the motion increases. I'm really not sure whether the larger autopilots have smarter software that adjusts to the sea-state better or not. My friend has an identical boat with a ST6000 and it tracks beautifully in a seaway. One thing to be aware of: the ST4000 is very lightly constructed with lots of plastic parts. The motor is quite small as well. All in all, I've been happy with the ST4000+ for the most part. I would rethink it again if I was in the market, but certainly the cost and installation ease were major factors when I bought it.

 

[Jose Venegas]

Advantage of auto-pilot below deck

Aside from being stiffer and allowing for a tighter control, the advantage of an autopilot drive below deck is that it provides backup means of steering in case the cable mechanism breaks down.I have been very please with my boat's B&G Network Autopilot with a hydraulic drive.The only problem I had was caused by a water leak into the pilot’s display unit during a downpour crossing of the golf stream last July. This killed the autopilot and all the Network instruments until the unit was disconnected. Happily the display unit was covered by a warrantee.When do we meet for lunch Derek?