"luc" wrote in message
ups.com...
who cares what the rudder does, as long as the boat is going in the
right direction?

How true. However sometimes the boat is not going in the right
direction! Now, a decent autopilot has to "think" how quickly the "wrong"
direction came about, how long does the Captain want to wait until we are
back on course, how many over (or under) steering swings he is comfortable
with, and how often these course errors are taking place.
How much should the autopilot move the rudder to achieve what makes the
Captain happy? How does the autopilot know when the rudder's pump or grinder
has moved the rudder to the correct position? Computer determined timed
motor runs are often used, but are not nearly as accurate and positive as
simply telling the "Iron Mike" where the darned rudder is at all times!

Old Chief Lynn

In article . com,
"luc" wrote:

who cares what the rudder does, as long as the boat is going in the
right direction?

Obviously you have never piloted or docked a large vessel.......

"luc" wrote in news:1142295506.893349.49870
@i39g2000cwa.googlegroups.com:

who cares what the rudder does, as long as the boat is going in the
right direction?



You'd have to watch our B&G Network Pilot steer a perfect course on
Lionheart with its rudder position sensor to see the difference. She also
has gyro input for rate-of-turn from a Raymarine Smart Heading Sensor.
Watching the wheel go through a turn at the moment of a waypoint turn is
like watching a ghost at the helm.

"Larry" wrote in message
...
"luc" wrote in news:1142295506.893349.49870
@i39g2000cwa.googlegroups.com:

You'd have to watch our B&G Network Pilot steer a perfect course on
Lionheart with its rudder position sensor to see the difference. She also
has gyro input for rate-of-turn from a Raymarine Smart Heading Sensor.
Watching the wheel go through a turn at the moment of a waypoint turn is
like watching a ghost at the helm.

Larry,

How did you connect the Smart Heading Sensor to the B&G Network Pilot? I've
got both of these (I'm using the Raymarine "gyro" to stabilize the radar
display and MARPA functions), but looking at the B&G manuals I can't figure
out how to attach the gyro input. The NMEA data decoded by the Pilot
doesn't include the ROT sentences

Contact me off-group if you prefer:
(remove the x's)

Thanks,
Paul

"Larry" wrote in message
...
"Paul" wrote in
:

Larry,

How did you connect the Smart Heading Sensor to the B&G Network Pilot?
I've got both of these (I'm using the Raymarine "gyro" to stabilize
the radar display and MARPA functions), but looking at the B&G manuals
I can't figure out how to attach the gyro input. The NMEA data
decoded by the Pilot doesn't include the ROT sentences

The SHS is Seatalk and connected to the RL70CRC display, which does the
translation to NMEA 0183 which it dutifully outputs to our Noland
Multiplexer with all the other Seatalk data that's turned on in the menu
of the RL70CRC's firmware. One of the loads on the output of the
multiplexer is the Network Pilot's NMEA input hooked to the master data
output bus.

In researching your question, as it has been a long time ago since I
installed this system, I looked into the Network Pilot Installation
Manual on:
http://www.bandg.com/pdfs/networkpil...tionmanual.pdf

It says on page 1-9 that Pilot uses:
"The Network PILOT uses the follow data from NMEA:
Cross Track Error (XTE), Speed Over Ground (SOG), Bearing: current
position to destination waypoint, Bearing: origin waypoint to destination
waypoint, Distance: current position to waypoint
Waypoint number
The following NMEA sentences are decoded, Note $ID is any NMEA
talker:
$IDAPA XTE, bearing origin to destination waypoint
$IDAPB XTE, bearing origin to destination waypoint,
bearing to waypoint
$IDRMB XTE, bearing and distance to waypoint
$IDXTE XTE
$IDVTG Speed over Ground
$IDBWR Bearing and Distance to waypoint rhumb,
waypoint number
$IDBWC Bearing and Distance to waypoint great circle,
waypoint number"

http://www.raymarine.com/raymarine/S.../Autopilots/81
198_1www.pdf
Over on the Smart Heading Sensor manual, page 32 in the specs, it says
the SHS puts out v2.3's $APHDM statement the v1.5 Network Pilot does not
read....hmm....

Now, I'm wondering if what Network Pilot is getting is a translated $ID
statement from The Cap'n, which digests the data from the multiplexer
before spitting out NMEA data to the bus. The possibility exists that
RL70CRC's chart plotter is also digesting SHS's $APHDM into other
statements before putting them on the NMEA bus, too. Both $ID and $AP
statements are continuously buzzing by on the main bus, and it does seem
to make the turns much smoother from the Pilot when SHS is online through
the RL70CRC plotter's firmware when a turn is forced upon it.

Or, SHS's data may never get to Pilot and Pilot is simply running on its
stored rate-of-turn data it keeps updating every time it turns the boat,
internally, which is also in the Pilot manual....??

By the way, which actuator and rudder position sensor are you using?
I've had some trouble keeping the hose clamped linear position sensor
tight to the linear actuator on Lionheart's installation. The clamps
seem to work loose over time as the linear sensor's mechanics don't seem
to be in perfect alignment, no matter what we do, as the plunger goes in
and out. When the hose clamps let it slip, of course, Pilot goes crazy
with the bad rudder position data.

Are you using the remote control on Pilot, too, and what do you think of
its operation?

A boat can never have too many electronic boxes or data statements...(c;


Larry,

Thanks for digging into this. I've already got a B&G fluxgate compass
hooked to the Pilot, and while I am pleased with the performance I'm curious
to see if the data from the gyro might tighten up the pilot response.
Running downwind with the swells, in near-surfing conditions gives the pilot
a real workout. (not that my heavy-displacement saiboat can actually
surf...)

I am using the RAM-2 drive, and the linear rudder-position sensor. I don't
recall any hose clamps on the position sensor, but I'll admit that I don't
remember exactly how it is connected to the RAM or rudder arm. In any case,
I haven't had any trouble with it slipping. I've not got the remote
control, but am tempted -- unless I decide to upgrade everything first.

I've got Raymarine chartplotters at the helm and navstation, a Raymarine
Smart Heading Sensor, and a Raymarine 4KW radome on the mast. Then there's
the B&G Network stuff: Pilot, Speed, Wind, Depth. I am sending the NMEA
data from the B&G to the Raymarine through the Raymarine seatalk converter
box, but haven't yet started sending data from the chartplotter to the
pilot. Some days I want to hook it all together, other days I want to keep
things separate do they can't drag each other down. Unfortunately, the
Raymarine can't decode the B&G wind data (wrong flavor NMEA).

I am also sending all NMEA data to a Shipmodul bluetooth NMEA mux,
bluetoothing to a PocketPC, where some programs I've written do automatic
logging, alarms, AIS, etc. I am using the PocketPC rather than the laptop
to keep the power consumption down. The laptop gets fired up for route
planning, radiofax, and SailMail radio email (and for watching DVDs).

I agree, marine electronics is fun. Sometimes to maintain the appropriate
perspective I have to remind myself that the boat sails just fine without
any of it!

-Paul
S/V VALIS - PSC44 #16 - Sausalito, California

"Paul" wrote in
:

Larry,

Thanks for digging into this. I've already got a B&G fluxgate compass
hooked to the Pilot, and while I am pleased with the performance I'm
curious to see if the data from the gyro might tighten up the pilot
response. Running downwind with the swells, in near-surfing conditions
gives the pilot a real workout. (not that my heavy-displacement
saiboat can actually surf...)

Us, too. The B&G compass works better than the Raymarine SHS compass.
It's just more stable. They are mounted about 5' from each other as near
centerline as I can get.

I don't think any of them work in the swells very well. They don't seem
to have an autopilot that has enough AI to anticipate the swells. The
gyro only is concerned with heading and there is no output that deals
with heel angle changes, altitude variations of the hull going up and
down, roll or pitch. The fluxgate's much faster input, directly
connected, gives it yaw input, but I think even that is way too slow for
the fast yaws in the swells and wind driven waves. Maybe someday one
will come out with a real gyro in 3 axis, but it's not here, yet.


I am using the RAM-2 drive, and the linear rudder-position sensor. I
don't recall any hose clamps on the position sensor, but I'll admit
that I don't remember exactly how it is connected to the RAM or rudder
arm. In any case, I haven't had any trouble with it slipping. I've
not got the remote control, but am tempted -- unless I decide to
upgrade everything first.

Look at how the linear position sensor is attached to the ramdrive.
There are some metal spacers then they run these big hoseclamps around
the two at these spacers. Eventually it works loose. The mounting
arrangement simply sucks. B&G doesn't make the sensor. It's a 3rd party
manufactured, outsourced box. Of course, when it finally slips, not only
does it slide linearly, but the body of the sensor rotates, which screws
up its resistance because you rotate it to calibrate it in the first
place. Poorly designed mount that needs replacement.


I've got Raymarine chartplotters at the helm and navstation, a
Raymarine Smart Heading Sensor, and a Raymarine 4KW radome on the
mast. Then there's the B&G Network stuff: Pilot, Speed, Wind, Depth.
I am sending the NMEA data from the B&G to the Raymarine through the
Raymarine seatalk converter box, but haven't yet started sending data
from the chartplotter to the pilot. Some days I want to hook it all
together, other days I want to keep things separate do they can't drag
each other down. Unfortunately, the Raymarine can't decode the B&G
wind data (wrong flavor NMEA).

Our Seatalk is the Raystar 120 WAAS/GPS, SHS, RL70CRC display/plotter and
CRAPPY 2KW radome that rots to hell every year and a half because it
breathes in moisture every night like a half-full gas tank and it rains
on the potmetal chassis just corroding the hell out of all the
unprotected electronics. Even the maggie rots with rust in there. We're
on our 3rd 2KW radome. Ever had your radome off since installation?
It's not us. Other Raymarine radomes in our marina are all in the same
situation...rotten inside. Electronically, two things happen. Rotation
fails or receiver sensitivity seems to go to hell, range drops, from the
rotting waveguide in the transmitter, rusting maggie power dropping and
the little flat PC board antenna corrodes up in the internal rainstorm.


I am also sending all NMEA data to a Shipmodul bluetooth NMEA mux,
bluetoothing to a PocketPC, where some programs I've written do
automatic logging, alarms, AIS, etc. I am using the PocketPC rather
than the laptop to keep the power consumption down. The laptop gets
fired up for route planning, radiofax, and SailMail radio email (and
for watching DVDs).

Cap'n Geoffrey bought the Noland multiplexer in a deal with Sailnet
before I took the project over. I didn't know Meindert or Shipmodul at
the time or I would have returned it and got his just because he has
fantastic support, even on this newsgroup. The laptop is a Dell
Latitude, a new one at the nav and the old one just running as a repeater
if the captain is in the aft cabin....or to show off, of course, for
guests...(c;

Lionheart has two banks of L-16H beasts. Lots of reserve power to run
laptops. Sailing instruments are all B&G Network, as is the Pilot. Of
course, B&G had to change that to increase "box sales" to get rid of the
standardized NMEA statements running in the Network wires. I'm glad we
don't have new B&G networks to deal with. Too bad, however, the old B&G
Network instruments are all version 1.5 NMEA 0183, not V2 or 3.

I'm a ham, W4CSC. A friend in Charleston runs HF phone patches for us
and checks emails. He's a great spam filter...(c;

The notebooks are also MP3 and DivX players. I have millions of files
from downloading alt.binaries for many years. Lionheart watched Master
and Commander 6 days before it came out in theatres..(c;


I agree, marine electronics is fun. Sometimes to maintain the
appropriate perspective I have to remind myself that the boat sails
just fine without any of it!

I'm just poor and lucky. Cap'n Geoffrey loves the toys. Sometimes I
just show up and he's already gotten a new box and says, "Can we (meaning
me usually) hook up this to the network?" Of course we can... He refers
to me as Lionheart's "Chief Engineer" to the guests. He used to try to
pay me, but my constant refusals finally paid off. I told him my pay was
simply to sail with him, more paycheck than I'd ever want. It's been a
great arrangement for both of us.

can't help but comment on the fun of the electronics while noting that
the boat sails fine without it. True enough, it's just for kicks.
Sometimes I have to remind myself of that, it's sailing I am interested
in, the other is just a sideline.

yeah, you are right about not piloting or docking a large vessel...
but you use an autopilot to dock your boat? Sometimes I wonder why
people even bother owning boats, if they need to have everything done
for them.

I use my autopilot only at sea, for long passages, when I can't steer
indefinately by hand. Docking I do by eye and hand.

luc wrote:
yeah, you are right about not piloting or docking a large vessel...
but you use an autopilot to dock your boat? Sometimes I wonder why
people even bother owning boats, if they need to have everything done
for them.

I use my autopilot only at sea, for long passages, when I can't steer
indefinately by hand. Docking I do by eye and hand.

I think he was talking about the rudder angle indicator. Sometimes when
docking you just want to center it or set a certain angle and wait
awhile for the boat to respond and the indicator makes it a lot easier
to tell what is going on.

It can also be handy for balancing the boat under sail too because you
can watch the the effects of trim changes on the rudder angle.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

On 16 Mar 2006 12:36:58 -0800, "luc" wrote:

can't help but comment on the fun of the electronics while noting that
the boat sails fine without it. True enough, it's just for kicks.
Sometimes I have to remind myself of that, it's sailing I am interested
in, the other is just a sideline.

You're not really boating unless you have all the requisite toys. And
at least some of them have to work. :-)