Autopilot choices on an E38

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rwthomas1

Sustaining Partner
Hello All,
It has come to my attention due to progressively longer sailing trips that a good autopilot is a must have piece of gear. I will not install a wheelpilot. The steering system in my boat is being torn down this winter. It makes a nice groaning noise when turning to port going down wind. Rudder will be removed, bearings checked/replaced, etc. The E38 presents several problems to autopilot installation:

The first issue is that it appears that the Yacht Specialties steering system allows more than 35* rudder deflection in each direction. This is a problem with Raymarine linear drives and requires a type 2 long drive and the requisite expensive upgraded hardware to deal with the extra rudder travel.

My YS setup is damaged. There is no rudder stop! There is a large aluminum bracket that mounts beneath the steering pedestal, under the cockpit floor that holds the sheaves, etc. for the steering system. There was a stop at some point but the stop was broken off by some PO. The quadrant will actually continue travel until it contacts the inner deck drain hoses.... Obviously not a good thing.

Lastly, there is not enough rudder stock exposed on my boat to allow a separate tiller arm to be clamped onto the rudder stock for attachment to the autopilot ram. I have seen one other E38 with a separate tiller arm however the owner claimed that this was a factory installed setup and this makes me think that the factory just made the rudder post tube just a bit shorter when it was built.

So here are my options as I see them:

With no way to attach a tiller arm I will have to do a modified quadrant ala CaptRon. He used a plate of aluminum with a starboard spacer to create an attachment point for the linear drive. Shouldn't be a huge problem to get this made.

To deal with the lack of rudder stop I can remove the damaged aluminum bracket and either bolt or weld on a new stop. The good thing about this is the size of the rudder stop can be adjusted to limit the rudder travel. I have read that travel beyond 35* is non-productive so the stop could be built accordingly. This should also allow the use of the less expensive Raymarine linear drive. I couldn't find any info on required rudder travel for any of the other autopilots, Comnav/Nexus, B&G, Simrad, etc. so I have to assume they will expect 35* deflection maximum as well. Figuring the rudder travel, etc. should be easy with the parts on a work bench.....

I originally had a Comnav/Nexus autopilot as the top choice. The prices recently however have increased astronomically. The Nexus is now $1000 more than when I first priced it. Others have increased as well. Raymarine, even though I am not the fondest of their gear, has remained the most affordable. I have also been walking the docks and talking to belowdecks Raymarine owners and then have all been pretty satisfied with their units. I don't think I can swing the autopilot this winter unless I go with Raymarine.

So what I am asking is for any input regarding the actual physical installation of the ram/linear drive on the steering system of an E38 or similar. The steering system needs attention and I would much rather do the autopilot while its all apart and not have to dig into it again next year. Thanks, RT
 
S

stbdtack

Member III
i have a Raymarine S1G with a type 1 linear drive. bolted a 1/4 inch SS plate to the underside of the quadrant. mounted the drive pin in the plate on a welded boss.

laminated marine ply to make a mount for the motor end, epoxy and screws to the underside of the cockpit floor and epoxy and cabosil to bond the other end to the hull. hardest part was getting the geometry right since the drive is angled aft a bit. my end stops work fine.

i would highly recommend the gyro version. it steers better than me or any of my crew can, and never needs rest:)
 
S

stbdtack

Member III
I have the YS steering that was original on the boat. the stroke length wasnt an issue. since i was placing the drive pin on the plate to be bolted to the quadrant, i could choose a spot that gave me full travel to the stops. also i had to move it off the centerline since the drive was angled slightly aft.

i used a CAD program to get the geometry correct then plotted it full size for a template. the type 1 drive is plenty powerful enough to steer the boat, even does a great job downwind. its really amazing to have the boat broach in 30kt SF bay wind and have the auto pilot recover perfectly.(without complaining:))
 
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stbdtack

Member III
BTW captron's install in the projects section is pretty close to what i did. the mount for the drive's motor end is different on my setup.
 
R

rwthomas1

Sustaining Partner
Thats very interesting. So what you are saying is you effectively decreased the distance/radius between the linear drive attachment pin and the rudder stock centerline on the quadrant. This dimension was altered (shortened) until the travel was reduced at the attachment pin to the requirement stated by Raymarine.

If this is the way it was done then that is certainly the easiest solution. I had considered this same solution but the installation manual from Raymarine was very specific that the linear drive attachment point MUST be 10", or whatever from the center of the rudder stock and then the travel MUST NOT exceed XX distance OR ELSE..... I was concerned the linear drive would not have enough power without the recommended lever distance on the rudder stock. It sounds like this is not an issue with your installation. This is the news I was looking for as it will greatly simplify the installation.

Obviously you are happy with the Raymarine. They have plenty of dealer support around here and that is a factor for me, figuring parts, service, etc. in the future. I have strongly considered Comnav/Nexus and B&G/Simrad however there are only a few dealers here. The Newport show is just around the corner so I will likely try to make a deal there.

Thanks, RT
 
S

stbdtack

Member III
i think mine ended up about 9" out. i can measure it when im on the boat again.

i was concerned about the lever arm distance too but it works really well. i think whats more important is how well the rudder is balanced(area fwd of the pivot vs area aft) i know my morgan with a barn door rudder would be much more difficult to move without a large lever arm. prob why its hydraulic.

being off the centerline of the quadrant was just a function of keeping the drive tangent to the radius arc when in the mid position and my drive unit angles back so i could get a good mounting point and clear the bulkhead.

i like raymarine well enough, their service is pretty good and seatalk is convenient to have all the instruments integrated. i dont know if they are the best but i've had good luck with them.

BTW, www.ultimatepassage.com really good prices and helpful staff on the phone:)
 
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