Wheel Pilot not responsive enough , requires modification

Oct 20, 2017
18
Hunter Legend 37.5 langkawi
Dear All,

My boat is a Hunter Legend 37.5 and i have installed a wheel pilot from Raymarine.
Its nearly the maximum displacement allowed for the wheel pilot and at wind speeds up to 20knots and swells, or going downwind , the autopilot struggles.
as i eventually intend to start cruising, i have a few questions.
1. Is other boat owners have this problem. i have asked Raymarine and they advised me to change as its too close to its max allowable displacement , and they have made adjustments
2. if i will like to modify the autopilot to one which can drive from the quadrant itself, has anyone done this before and does anyone have any pictures to share for these kinds of modifications.
i am from Malaysia and the sailing community here is not so active and there are less boats here.

Any assistance and advise is most welcome.

ALso another question to Legend owners - does the boat have a lot of weather helm - has anyone experienced this before and what steps did you all take.
I have a 140 genoa too installed on furler and its fully rolled out.

rgds

Fabian
 
Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
I think the problem with both the autopilot struggling, and definitely the weather helm, could be solved by working to balance the boat by reefing the main and genoa. If the boat is overpowered, it will heel excessively, be slower, and have weather helm, especially sailing upwind, but possibly when surfing downwind and sailing a reach as well. While I do not own your specific boat, I know that a properly powered boat for the given wind will have a light helm that can be steered with little force, often with one’s fingertips. Your boat’s owner’s manual may have instructions about how much to reef in particular wind speeds. Mine does. However, you will have to experiment.
If your steering requires a lot of force at all times in motion or not, it seems you have a mechanical problem that can be traced through points of friction, like cables, shafts, and such.

I am sure Hunter owners will have more to say.

Thanks,
Andrew
 
May 1, 2011
4,187
Pearson 37 Lusby MD
Its nearly the maximum displacement allowed for the wheel pilot and at wind speeds up to 20knots and swells, or going downwind , the autopilot struggles.
I had the same problem on my boat, and it got far worse when I replaced the ST4000 with the SPX-5 unit - Raymarine put some more "protection" in for the small motor. It didn't matter what I did to balance the sail plan, the wheel pilot just couldn't handle it. I changed to a below deck unit (type 1 linear drive) and all my problems were solved.
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
Agree with the above, also you may benefit from an upgrade to a more sophisticated course computer (such as one that contains a gyro). It’s challenging for APs to keep up with rolling down swells, even more so with weather helm as an added factor. Reef the main (or even strike it if the wind is strong) when sailing downwind to see if sailing with proportionally more headsail helps.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
you may benefit from an upgrade to a more sophisticated course computer (such as one that contains a gyro).
While the OP doesn't state the exact model or vintage of RM AP, all of the current ones have multiple sensors that include a gyro:
"3-axis digital accelerometer | 3-axis digital compass | 3-axis gyro digital angular rate sensor"

The problem with boats this size is that the EV100 wheel pilot is just not up to the task. Unfortunately, upgrading will require a new ACU as well as linear drive and tiller arm.
 
Jan 11, 2014
11,320
Sabre 362 113 Fair Haven, NY
As others have stated, the Wheel Pilot is too small for the job. It will work in calm water and light air, but will struggle when the wind pipes up.

For long distance cruising a below deck AP is the way to go. Raymarine makes them and B&G. I'm partial to B&G. They are however, expensive and need adequate electrical power to work.

Another option is to use wind vane self-steering. These work well when sailing based on the wind direction. Many long distance cruisers use them.

This video just came out and is nice over view of APs.

 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
When you upgrade to a below-deck system, you may want to keep your wheel pilot installed, as backup.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
We have a Raymarine EV100 on our Seaward 25. Downwind with waves it does have issues, and many times we turn it off and hand steer. Usually it's a case of over compensating or under compensating, and there aren't enough setting adjustments to fine tune the EV100 (older units had more operator adjustment settings). Not sure if adding a rudder sensor would help, but so far, haven't done that. Other points of sail seem to be fine...usually. On your boat, which is even heavier, I doubt you'll be totally satisfied with it. Do make sure your settings (especially hardover time) are set correctly.

On our Catalina 350 we have a Raymarine below deck system. It's a totally different animal. Keeps us on track no matter what the conditions are. We sailed on a fair amount of rough water on Lake Erie and Lake Huron this summer and it never skipped a beat.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
When you upgrade to a below-deck system, you may want to keep your wheel pilot installed, as backup.
You won't easily do this if you upgrade the ACU and drive and keep the EV1. But. it's an interesting idea, to have a backup AP.
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
You won't easily do this if you upgrade the ACU and drive and keep the EV1. But. it's an interesting idea, to have a backup AP.
But it can be done if the two systems are independent. Not difficult unless you want them both to interface to the CP and/or the same i70 AP control head. It might be possible to make those connections if they're readily accessible.
 
Jan 11, 2014
11,320
Sabre 362 113 Fair Haven, NY
But it can be done if the two systems are independent. Not difficult unless you want them both to interface to the CP and/or the same i70 AP control head. It might be possible to make those connections if they're readily accessible.
Provide separate power sources to the 2 AP systems. Only provide power to the AP that is in use. All that is needed is 2 circuit breakers. NMEA 2000 will continue to work even if one system is off line.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I think it's a bit extreme. Wouldn't it be better to carry some spares for the below decks AP system? I have a spare linear drive on board, that I can swap in about 5 minutes. I think that's probably the weakest link.
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
I think it's a bit extreme. Wouldn't it be better to carry some spares for the below decks AP system? I have a spare linear drive on board, that I can swap in about 5 minutes. I think that's probably the weakest link.
I think the weakest link varies in each system. The rudder position sensor and heading sensor also tend to be sensitive (from an electrical standpoint). Anything with low power diodes is subject to failure from the EMF of nearby lighting strike, even if not directly hit.
 
Feb 11, 2017
122
former Tartan 30 New London, CT area
Seems there are two things going on here, upwind balance and autopilot.
First, learn to balance the boat for upwind sailing. Boat should have a little (2-3 deg of rudder) weather helm. You should calibrate your wheel so you know how much the rudder is turning for 1 spoke on the wheel. If you're going over 3 deg, it's time to change the rig - perhaps reef the main? Perhaps rake the mast forward a bit? Once this is done, the autopilot should have an easy time on the wind. The other time an autopilot is valuable is under power - driving with the engine going is BORING!
Off the wind/down wind is a test of the autopilot, but then this is when steering is fun!
My only experience with a below deck autopilot on a boat your size is with a 39' custom back in '02 or '03 - drive head (as I recall) was electro-hydraulic from B&G. One recommendation is to make the drive head easily detachable from it's tiller - even when turned off, it puts quite a bit of drag into the wheel steering.
Get the friction out of the system! I've seen 40+ foot boats with tillers - the owners hated the friction associated with most wheel systems. When you turn your wheel and let it go, what happens? Will the rudder turn the wheel back?
Final thought is to be careful of sales hype from the manufacturer. The 3 axis/measure everything sensor is a cheap part - they glue one to the circuit board and hit you with the sales pitch. They don't mention the fact that it's only wired up for one axis in heading, and there's no logic to handle the gyro info. No autopilot will be as good as a decent hand on the wheel who can see the waves coming! In my racing days there was one couple that I loved to have as crew because she was so good a driving the boat. He and I would trim things and she would tell us how we were doing.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
But. it's an interesting idea, to have a backup AP
This would likely require a separate controller and possibly a separate control head as well, unless one were to go through the whole regime of calibration if they were swapped over, and moving of wires. Easier to say than ultimately to do.
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
Easier to say than ultimately to do.
IMHO it can be done. He's already got the backup equipment. Moving a wire or two (if they are already run and everything is physically in place) can be done easily at sea in 10 minutes or less (if planned for) and re-calibration is a lot easier than hand steering hours at a time.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
It's a kooky idea, and swiching over would be more involved than "moving a wire or two." Control head, ACU, course computer, rudder reference, drive unit....
 
Jan 11, 2014
11,320
Sabre 362 113 Fair Haven, NY
It's a kooky idea, and swiching over would be more involved than "moving a wire or two." Control head, ACU, course computer, rudder reference, drive unit....
He has a wheel pilot installed. The computer unit for the wheel pilot is likely too small to handle the loads of a below decks AP. Thus, he would need to install and drive unit, computer, rudder sensor, and arm for the steering. It could use the same compass which is on the N2K network.

The below decks AP is then a completely different and independent system. Installed correctly, there would be one breaker for the wheel pilot and one for the below decks AP. All that is necessary is to turn off one AP and turn on the other.
 
Jul 23, 2009
857
Beneteau 31 Oceanis Grand Lake, Oklahoma
When I upgraded from a ST4000+ to a ST6000+ I expected the new unit would hold a course better with the gyro. It did not. After reading the manual I figured out that the gyro is only used for the self learning during the initial setup and calibration. The manual didn't come right out and say this. The gyro was optional on this unit and reading the manual for with and without the gyro it seemed clear the the gyro was a waste of time and money. I had to manual adjust all the settings anyway. I have no experience with the newest units.