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-   -   ST60 Wind Transducer does not show correct true wind (https://www.sailnet.com/forums/general-discussion-sailing-related/264690-st60-wind-transducer-does-not-show-correct-true-wind.html)

TakeFive 09-13-2016 01:52 PM

ST60 Wind Transducer does not show correct true wind
 
I've registered for the Raymarine support forum, but their site admins are taking their dear old time approving my membership. In the meantime, I am hoping that one of you might have a hint or two to help me address my problem:

My configuration:

I have ST60 Wind, Speed, and Depth transducers, ST4000+ wheel pilot, and a Garmin 2010 chartplotter. These instruments came with my new (to me) boat. I did not install them.

My speed transducer's paddlewheel is sitting in the bilge. I have the blank in the through-hull, and have the speed control head set to display SOG.

My background:
I have had Raymarine ST60 instruments on a past boat, and have quite a bit of interfacing experience with SeaTalk and NMEA 0183 protocols.

What works:
My wind transducer shows apparent wind fine. It may need a little tweaking of the calibration, but it's not terrible, and I have more important things to fix first.

What's broken:
The wind transducer is not showing the correct true wind. It shows exactly the same speed for true wind that it does for apparent wind, regardless of speed or direction of the boat. True direction is also almost the same too (within a few degrees). I can be motoring 5 kts straight into a 5 kt wind, and both true and apparent wind will show up as 10 kts. I can be sailing on a broad reach, and true/apparent wind speed are the same, and direction almost exactly the same. The direction agrees with visual observation of my masthead Windex.

The first hypothesis might be that the instrument is not getting any speed data, or is getting a value of zero (since true=apparent when speed=0). But the speed control head shows SOG just fine. Although I have not opened up the NavPod to view the wiring, I assume that the chartplotter's output wires are connected to the NMEA input terminal on the Autopilot, and the Autopilot is passing that data through to the SeaTalk netowork. That's the only way I can see that the speed control head would be able to display SOG.

So this leaves the question: Why isn't the wind transducer making the appropriate vector calculations to display the correct true speed and direction?

I've looked through the manual and cannot find any settings to change speed input (for instance, from SOW to SOG). So I'm stumped.

SVAuspicious 09-13-2016 03:00 PM

Re: ST60 Wind Transducer does not show correct true wind
 
I love the easy ones.

Raymarine only uses STW (from the paddlewheel) to calculate true wind. With the paddlewheel in the bilge the algorithm gets 0 so true = apparent. Clean your paddlewheel and stick it in the hole.

oldlaxer1 09-13-2016 04:25 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by SVAuspicious (Post 3658506)
I love the easy ones.

Raymarine only uses STW (from the paddlewheel) to calculate true wind. With the paddlewheel in the bilge the algorithm gets 0 so true = apparent. Clean your paddlewheel and stick it in the hole.

So if the paddlewheel is gummed up and reading low, True will indicate less on a downwind leg?

TakeFive 09-13-2016 04:31 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by SVAuspicious (Post 3658506)
I love the easy ones.

Raymarine only uses STW (from the paddlewheel) to calculate true wind. With the paddlewheel in the bilge the algorithm gets 0 so true = apparent. Clean your paddlewheel and stick it in the hole.

That's what I suspected. First thing I looked for was a menu in Dealer Setup that would allow selecting SOG for this, but didn't find it in the manual. As I'm sure you know, SOG is a much more reliable and accurate basis than SOW for the required vector calculations. I guess the only logical explanation for doing it that way is that GPS speed was much less common back when the ST60 series was developed.

Unfortunately my paddlewheel is in a very inconvenient location. The air conditioner tray was installed right over top the through hull, which makes it all but impossible to reach. If I could contort my arm and wrist to get to it, I am really concerned that I might get the blank plug out, and not be able to get the angle right to get the paddlewheel (or the blank) back in. Meanwhile, the water continues to pour into the bilge.

Also, my paddlewheel is not free-wheeling. It has severe resistance, so it needs servicing. I can't figure out a way to disconnect the cable to get it to a work bench where I might be able to do some decent cleaning on it. (Any hints on how to do this?)

It is good to have an explanation for this, so I can stop wondering what's wrong. (Thanks!) I will just use apparent wind for now.

I have a few options to circumvent this problem. I have a Raymarine-NMEA converter from my old boat that could take the apparent wind from SeaTalk and feed it by Wifi to my tablet software that can convert to true wind using SOG from the GPS. I doubt that the converter will fit into my NavPod, so running the wires to a remote location will be a tedious job. That will go on my ever-growing list of winter projects. Maybe someday I will get to it.

BarryL 09-13-2016 06:31 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Hey,

Some info for you:
If the paddlewheel isn't turning freely you have two choices; Remove the paddle wheel (use a paper clip or something like that drive the wheel out. Then use emery paper to clean the pin. Or, buy a new paddle wheel. The kit comes with wheel, pin, and gaskets. Unfortunately, that won't help you to install the paddlewheel. If you do decide to install the wheel, make sure you paint it with antifouling paint. There is special paint for transducers, but they don't seem to work well. You can dive the boat to clean the wheel too.

Your garmin plotter SHOULD be able to display true and apparent wind. My 740S does and it uses SOG instead of STW. I have an 'environment' page with wind information. This assumes that your plotter is getting wind data! If not, you can convert the old seatalk to NMEA 2000 and then you are set!

Good luck,
Barry

Maine Sail 09-13-2016 06:52 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by TakeFive (Post 3658442)
ST60 Wind Transducer does not show correct true wind


Snip....

My speed transducer's paddlewheel is sitting in the bilge.


Can do true without the speed log....

TakeFive 09-13-2016 08:16 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by Maine Sail (Post 3659010)
Can do true without the speed log....

Haven't the newer ones been updated to accept SOG from a GPS?

senormechanico 09-17-2016 08:05 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Move the air conditioner??

albrazzi 09-17-2016 10:14 PM

Re: ST60 Wind Transducer does not show correct true wind
 
If you put it in make it easy to get to, you WILL need to clean regularly.

capta 09-17-2016 10:35 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by Maine Sail (Post 3659010)
Can do true without the speed log....

All righty then. I have a ST-60 speed log that always reads slow by several knots, so please explain.
Is my Garmin 3010 too old to connect to the ST-60 system????

TakeFive 09-19-2016 10:56 AM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by senormechanico (Post 3663993)
Move the air conditioner??

Not a chance.

The A/C was installed less than 3 years ago by PO. Airflow is great (excellent ducting), through-hull locations are great, everything works perfectly, and I used it all summer. Why would I rip it all out and move it and all the ducting somewhere else?

Paddlewheel speed is obsolete technology, needs constant maintenance, and often gives questionable readings even when it's maintained. My only reason for wanting it is the wind transducer wants it for true wind speed and direction while underway - and those values are as unreliable as the STW readings.

If there is no way for the wind instrument to accept SOG instead of STW (and that's not proven yet, since someone said there may be a setting), then I will send apparent wind (and all other SeaTalk information) to my tablet chartplotter by WiFi and have software calculate true wind. I already have all the electronics to do this (brought them over from my prior boat), I just need time in the offseason to do it.

It would have been nice if I could figure a way to have my wind control head accept SOG instead of STW, but if I can't then I'll do it a different way.

SVAuspicious 09-19-2016 11:14 AM

Re: ST60 Wind Transducer does not show correct true wind
 
I may have a chance to confirm using SOG v. STW on a Garmin chartplotter today.

Seeing reliable STW and SOG gives you good data on currents.

TakeFive 09-19-2016 11:37 AM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by SVAuspicious (Post 3665961)
I may have a chance to confirm using SOG v. STW on a Garmin chartplotter today.

Seeing reliable STW and SOG gives you good data on currents.

Hi Dave, I do realize that comparing STW and SOG can get useful information if STW is reliable. But having moved from the 2-3 kt currents of the Delaware River to the Chesapeake, the currents are too low for me to care much at this point. (I know that will eventually change.)

As for the Garmin chartplotter, my very old 2010 model does not display wind data, so even if I could convert wind data from SeaTalk to NMEA0183 on a wire, it would not help me. However, your information could be helpful if I want to consider a future upgrade to a newer Garmin model.

For now, my Garmin chartplotter is my foul weather backup. In dry conditions, my primary chartplotter is OpenCPN on a windows tablet, nicely mounted at the top of my binnacle. And once I have my SeaTalk-Wifi converter installed, it will give a very nice comprehensive display of all my current nav data. But ultimately a purpose-built chartplotter display is the more bulletproof solution.

Maine Sail 09-19-2016 12:20 PM

Re: ST60 Wind Transducer does not show correct true wind
 
If you want more accurate true wind data for your "boat" then add an ultrasonic speed log.

Using SOG gets you ground-wind data not true wind data for your boat, which is moving through water. I don't know of any ST-60 or ST-60+ wind instruments that can read SOG sentences unless a software update happened that I missed. ST-60's use STW (speed log (if well calibrated), COG (usually the flux gate (if well calibrated) and Apparent wind to attempt to calculate true.

If you really want "true wind" on a boat.... Good luck...:wink It's a rough guide at best...

xort 09-19-2016 12:33 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Ultrasonic speed log?
I'm having a similar set of issues. ST60+, ST6000+ and a 3210.
Even with a new paddlewheel I was getting poor true wind readings

TakeFive 09-19-2016 01:33 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by Maine Sail (Post 3666170)
If you want more accurate true wind data for your "boat" then add an ultrasonic speed log.

Using SOG gets you ground-wind data not true wind data for your boat, which is moving through water. I don't know of any ST-60 or ST-60+ wind instruments that can read SOG sentences unless a software update happened that I missed. ST-60's use STW (speed log (if well calibrated), COG (usually the flux gate (if well calibrated) and Apparent wind to attempt to calculate true.

If you really want "true wind" on a boat.... Good luck...:wink It's a rough guide at best...

To me, it's not worth investing any significant money. It is worth some effort to adjust my current hardware to extract the most information possible.

There are other things that are much more important right now (such as reliable shifting of my transmission), so this one's down the list for the offseason...if then.

Maine Sail 09-19-2016 02:11 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by xort (Post 3666194)
Ultrasonic speed log?
I'm having a similar set of issues. ST60+, ST6000+ and a 3210.
Even with a new paddlewheel I was getting poor true wind readings

Yes Airmar makes an Ultrasonic speed log called the CS4500 and it is available for all brands. This is not a new prodcut just one that you don't hear much about because they are pricey, about $700.00 - 750.00 just for a plastic transducer (P17). While not inexpensive they work really well, are more accurate & remain more accurate than a paddle wheel. They require virtually no maintenance.

They also offer a converter box to get it over to NMEA 0183 or NMEA 2K but the Raymarine ITC-5 can also convert the analog signal as well as wind, depth/temp, rudder and flux gate to NMEA 2K.

xort 09-19-2016 02:29 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Thanks...but no thanks!
I just recently blew my wad on some electrical. ;-)
Tapped out!

overbored 09-19-2016 03:00 PM

Re: ST60 Wind Transducer does not show correct true wind
 
Quote:

Originally Posted by Maine Sail (Post 3666426)
Yes Airmar makes an Ultrasonic speed log called the CS4500 and it is available for all brands. This is not a new prodcut just one that you don't hear much about because they are pricey, about $700.00 - 750.00 just for a plastic transducer (P17). While not inexpensive they work really well, are more accurate & remain more accurate than a paddle wheel. They require virtually no maintenance.

They also offer a converter box to get it over to NMEA 0183 or NMEA 2K but the Raymarine ITC-5 can also convert the analog signal as well as wind, depth/temp, rudder and flux gate to NMEA 2K.

Just add this set up last month and was $635 with plastic housing about $100 more for bronze housing, it works great and I had one one my old boat and it worked for 6 years while I had it and is still working today.


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