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Chip Hindes wrote:Mike, I'd be interested to hear of your results. I had exactly the same idea, but I know you can't just string these things together like Xmas tree lites and expect them to work.

Actually, mine IS strung like Xmas tree lights (well, kinda).

The main location for my GPS is at the pedestal, and the NMEA wire goes from here to the port companionway electrical panel area. I also have another mounting location for the same GPS (above the aft galley seat) so that I can move it into the cabin at night for an anchor alarm. The NMEA from here also leads to the panel area. Behind the panel, there is a junction of NMEA wires... the two "talkers" (though only one "talks" at a time, of course) from each of the GPS locations join with wires leading to the inputs of the VHF, wind instrument, and autopilot.

Believe it or not, it all works!

I figure a switch before the ST4000's NMEA in, with one side coming from the GPS, and the other from the wind instrument, won't stop this setup from working, though I will wire it up and test it it before drilling a hole to mount the switch.

--Mike

Mod is posted.

Jumpering the "Data in -" to chassis ground works as Moe stated.

I believe I stated before the ST4000 has no belt. That wasn't exactly correct. I does have a belt, but it's internal to the wheel ring.

This thing works great on the trailer, but response to the helm is a tad slow

I can't wait to try it with the boat actually in the water.

This thing works great on the trailer, but response to the helm is a tad slow

The response is adjustable in the control unit. If you set it too fast it wags the boat. If you set it too slow it also wags.

Doesn't seem to help.

I think perhaps you two are talking about different things. Chip is probably saying that it looks like the wheel is not turning very fast... Scott is referring to the rudder gain setting.

I don't think rudder gain has anything to do with how fast the wheel turns... I think it controls how "aggressive" the attempt to make the turn will be. The wheel won't turn any faster if rudder gain is cranked up, it will just turn further.

--Mike

The wheel won't turn any faster if rudder gain is cranked up, it will just turn further.

Not further, Sooner. It will react more quickly.

Also if in fact speed of turning is the concern, as the unit reacts, the further off track you are the quicker the wheel turns. Small course correction = slow/ small wheel turn, large course correction/ tack = fast large wheel turn.

P.S. The auto tack feature is on of the coolest things about this unit, very handy for single handing. It can be set to use compass settings or if you have a wind unit it will tack 90 deg by wind angle. It will also hold course by wind angle and respond to shifts.

Very cool.

On edit: I feel like mine reacts about the same speed and intensity as me steering. Im carefull not to brake my boat with the rudders and to much input. ie: turn a little, let the boat react, turn a little more.?

You guys are too much. Didn't you catch the smiley face? What I essentially said was, the boat doesn't turn (at all) when it's on the trailer.

Haha, gud wun!! It prob doesnt turn on the trailer cause you still got winter air in yer tires.

Aw Shucks Chip - you ruined a perfectly good segue into a blue hull coupling into the trailer autopilot........

Sorry to resurrect such an old thread. I've been searching archives for info on completing my ST5000+ Tillerpilot, and wanted to add "search links" to ease future searches for the ST4000+ (Plus) Wheelpilot.

Regarding the rudder postion sensor ... Chip, the RPS could be mounted dead center of the draglink bar, also accomplishing your "rudder averaging" objective? I'm thinking that a plate or bracket could mount it over the motor well.

Meantime, Raymarine suggests the fluxgate compass should be mounted close as possible to the pitch & roll centers (see below). I know there are two decent options for mounting in the 26X:

• 1. Just under cockpit, right behind the companionway ladder (IIRC, this is Chip's choice);
  2. Just starboard of the aft CB trunk, the inside aft face of the dinette seat.

Duane's choice was under the aft dinette seat (#2) but I use same exterior face for a fire extinguisher. The companionway seems closer to the roll center, but I'm not sure where the pitch center is?? Any debate of the respective merits of each option?

Search notes for Mod Pages & other threads:
Chip's ST4000+ Mod Page
Mike Caswell's ST4000 Mod Page
Warning re ST4000 on 26M
Auto tack???
Raymarine Autopilot Woes
Raymarine Autopilots

[quote=""Raymarine"]The correct positioning of the fluxgate compass is crucial if ultimate performance is to be achieved. To minimize gimbal disturbance, the fluxgate should ideally be positioned as near as possible to the pitch and roll center of the vessel.

Make sure the fluxgate compass is located on a suitable vertical surface. The fluxgate should be positioned at least 2ft. 6in. (0.8m) away from the vessel's steering compass in order to avoid deviation of both compasses. To avoid compass deviation and reduction in sensitivity of the sensor, the fluxgate must also be positioned at least 3ft. away from iron objects, ( engine, keel, loudspeakers), as well as other electrical devices such as batteries, AC sources, chargers, speakers, audio equipment etc..

If any doubt exists over magnetic suitability of the chosen site, the position may be surveyed using a hand bearing compass. The hand bearing compass should be fixed in the chosen position and the vessel swung through 360 degrees. Relative differences in reading between the hand bearing compass and the vessel's main steering compass should, ideally, not exceed 10 degrees on any heading.

Temporarily mount the compass sensor in the desired location, if the deviation correction during your seatrials exceeds 15 degrees, then you need to find a better location for the compass sensor.[/quote]

Memo: the following Q&A in Raymarine's Tech data seems very, very curious ...
They advised mounting the fluxgate SIX FEET above deck, for a steel hulled vessel ~~!!!

Question: I am interested in installing the ST4000 GP Plus auto-tiller to my steel boat (the boat weighs 14,000 lbs.) If I mount the fluxgate compass low in the bilge, fully surrounded by the steel hull, will it operate correctly, assuming the normal calibration routine?

Answer: Thank you for your inquiry. The induced magnetism of the steel hull will cause excessive compass deviation and it is most unlikely the compass will function correctly when within the steel hull. We have found that on steel commercial vessels and steel hulled yachts which are continuously at sea, then the compass will work. This phenonomenon is due to the fact that when a vessel spends extended time at sea, the induced magnetism in the hull is eliminated.

Our advice would be to install the compass about 2m above the main deck on a non-ferrous mast or structure - note too high above the deck and the compass will be affected by pitch and roll, too low and it will still be swamped by the magnetic field of the boat.

Regarding the rudder postion sensor ... Chip, the RPS could be mounted dead center of the draglink bar, also accomplishing your "rudder averaging" objective? I'm thinking that a plate or bracket could mount it over the motor well.

Yes. Mounting it dead center on the link bar does accomplish the averaging I was looking for.

However, any looseness or lost motion between the bar and rudder brackets will actually remain "lost", partially defeating the purpose of the rudder reference unit.

I know there are two decent options for mounting in the 26X:
1. Just under cockpit, right behind the companionway ladder (IIRC, this is Chip's choice);

Nope. My choice was 2. Initially I had a speaker for the stereo mounted too close, and it screwed up the correction factor big time (over 50 degrees, when the max is fifteen). I moved the speaker, and everything is fine.

I have a fire extinguisher mounted quite close to mine, and it does not affect the compass. There are no ferrous parts in my extinguisher; it is 100% aluminum and non-magnetic stainless. Try this: with the boat on the trailer or in some way held stationary, "mount" the compass with duct tape in its chosen location. Check the compass reading on the control head. Then remove the extinguisher and bracket and move it around the compass while observing the readings. If it doesn't change or only moves a couple degrees, don't worry about it; you'll calibrate it out when you "swing" the compass. Otherwise, find another location for the extinguisher or the compass.

The pitch center ought to be pretty close to, maybe a little aft, of halfway down the waterline length.

The best Pitch & Roll center on the M is right down at the foot of the companionway ladder at the cabin floor. (this is very much between 1/3 & 1/2 way along the waterline, I measured it all out and IIRC it is about 9' forward of the transom) To put it there you need a thermostat cage (the kind they use to keep unwanted fingers off the thermostat) to protect it from clumsy feet. The newer M's have a battery behind that surface which may interfere (could relocate the battery) but it is very thick there to support the ladder. I do not have a battery there, mine is way down at the stern transom under the steering linkage so no problem. Actually, I mounted mine on the opposite side of that surface facing the stern so that no clumsy feet could step on it. During sea trials I swung it and corrected for 180 degrees. As for the thingy the warning thread mentioned that is not long enough, I just took a 4" PVC cap and cut & carved it to fit under the pedestal then mounted the thingy on that so that it could reach the wheel and stick into the hole to stop the spinning. Just love that nautical word "Thingy"