Rudder limit

M

Mad Sweeney

.
May 24, 2019
5
Hunter 35.5 Ludington, MI
Hi All,
Just bought a beautiful 1991 Legend 35 and installed an Ev 100 Raymarine Autopilot and, in the course of commissioning the device, it wants to know the “rudder limit.” Perhaps this is common knowledge amongst wheel steered sailboat owners that no one mentions it, because I cannot find that figure online anywhere, and Marlow Hunter has not responded. Any help will be greatly appreciated. Thanks-
 
rgranger

rgranger

.
Jan 19, 2010
12,417
Hobie 16 & Rhodes 22 Skeeter Charleston
This thread talks about it

http://www.ericsonyachts.org/infoex...udder-Limit-and-Hard-Over-Time-settings-E32-3

It seems that it is not a function of your boat but rather a preference of the captain. For example, you do not want your rudder all the way over on a tack so you set the limit. In the above thread the user said he left his auto-pilot at the factory preset values. That would be a good place to start IMHI and then if you don't like how the boat responds to those settings you can adjust the settings in your auto-pilot.
 
BigEasy

BigEasy

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Jun 21, 2004
2,534
Beneteau 343 Slidell, LA
On my ST4000+ auto pilot, the recommended setting was 20 using “Catalina Cocktail” auto pilot settings.
 
jviss

jviss

.
Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
I've spent a lot of time studying this for below deck installations, but not so much for wheel pilots. But, one guiding principle is that you should restrict the AP to less than the rudder stop range, so you don't drive against the rudders stops. That's the starting point.

I don't know the rudder limit on your boat. I measured it on the Catalina 36 I had at the time. (I had actually made my own rudder stops, as the factory one was too much.)

By the way, in that link to the Ericson forum, there's some sketchy info; folks don't seem to understand that the recommended placement of the sensor is at the center of motion of the boat, e.g., at the waterline and centerline; and then mount it in the lazarette and comment that the AP is "busy."
 
Red_Dog

Red_Dog

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Nov 4, 2018
155
Hunter 28.5 Catawba Island, OH
Before installing my wheel pilot, I turned the to the stops. I then wrapped a piece of red (port stop) and green tape (starboard stop). Counting revolutions between stops, I found neutral rudder.
The wheel pilot setup didn't ask for a stop distance.
However, I'm happy to know all three positions. Mine turned out to be, with a 24" wheel, 1-1/4 turns stop to stop (or lock to lock, if you wish to think of it in those terms).
I'm not sure about auto-pilots, but, I think jviss might be on to something with the location of the sensor, and restricting your AP to less than the actual stop.
 
M

Mad Sweeney

.
May 24, 2019
5
Hunter 35.5 Ludington, MI
Hi — thanks for your input. I think this is what to do, combining your various advice: Since the wheel pilot will have stops on the chains, I can locate the stops per Red Dog, then, beginning with a relatively low number as the input of the angle limit, determine how far the AP turns wheel at incrementally larger limit inputs. That way, I won’t have the Ap working against the rudder stops. I suppose, if I were better at measuring, I could even determine how many degrees of rudder turn is produced by x amount of pilot wheel turn. Thanks for helping me think through this. My previous boat, btw, had a tiller. Cheers.
 
Red_Dog

Red_Dog

.
Nov 4, 2018
155
Hunter 28.5 Catawba Island, OH
"My previous boat, btw, had a tiller"
That's part of the problem with some of these mid-size Hunter boats - pedestals rather than tillers. My 28.5 cockpit is very crowded because of the pedestal. This year I put a 24" wheel on it, and it's still a bugger to get around. BTW, I'm six foot, weighing 145-150, so I'm not a big guy.

"Since the wheel pilot will have stops on the chains, I can locate the stops per Red Dog . . ."
Are you using auto pilot and wheel pilot interchangeably? My understanding is they are two related, but different animals.

I have an old Simrad WP30 wheel pilot. I started with the gain and sea state setting set at 5 (0-9 scale). Over the last couple of months both have increased. The gain is now set at 7 and the sea state at 8. It's very happy with those settings. The wheel pilot has never gone to the stops. I counted turns stop to stop so I know where they are on the wheel.
 
dziedzicmj

dziedzicmj

.
Aug 13, 2012
533
Catalina 270 Ottawa
Mad Sweeney said:
Hi All,
Just bought a beautiful 1991 Legend 35 and installed an Ev 100 Raymarine Autopilot and, in the course of commissioning the device, it wants to know the “rudder limit.” Perhaps this is common knowledge amongst wheel steered sailboat owners that no one mentions it, because I cannot find that figure online anywhere, and Marlow Hunter has not responded. Any help will be greatly appreciated. Thanks-
Click to expand
This might be way too late, but just in case you are still looking for answers...

The EV-100 has changed the settings, so the ST4000 or even earlier versions of EV-100 solutions don't necessarily apply.

The first question is if you have the rudder reference installed. I assume you don't (it is not part of the EV-100 package).
If you don't have it, you have to use the "Hard-over time" setting to let the system know how fast and how far the wheel can turn. An interesting thing is that the higher that setting, the faster the wheel turn. The default setting of 6 s is, in my opinion, too low. You are probably closer to 20 s, or even higher. My measured number is 24 s (but a completely different boat).
 
JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,468
Hunter 430 Waveland, MS
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