Autohelm ST50 Wind Instrument ??

[PlumBob]

I've got an old Autohelm ST50 wind instrument, that used a Raymarine transducer (wind speed and direction transducers). The transducer finally gave up - the anemometer would no longer turn freely. My rigger had a new transducer that he put on (right before he moved to Key West) - but now the display is approximately 90 degrees off - when the wind is 000, the display needle shows 270.



The Autohelm manual describes how to realign the instrument, but these factory instructions aren't recognized by the display head.



Any experience or advice? (Other than, of course, buy a new wind instrument, which is where I may have to go.)


Thanks in Advance


PlumBob

[Ssas5342]

Originally Posted by PlumBob

I've got an old Autohelm ST50 wind instrument, that used a Raymarine transducer (wind speed and direction transducers). The transducer finally gave up - the anemometer would no longer turn freely. My rigger had a new transducer that he put on (right before he moved to Key West) - but now the display is approximately 90 degrees off - when the wind is 000, the display needle shows 270.



The Autohelm manual describes how to realign the instrument, but these factory instructions aren't recognized by the display head.



Any experience or advice? (Other than, of course, buy a new wind instrument, which is where I may have to go.)


Thanks in Advance


PlumBob

Originally Posted by PlumBob

I've got an old Autohelm ST50 wind instrument, that used a Raymarine transducer (wind speed and direction transducers). The transducer finally gave up - the anemometer would no longer turn freely. My rigger had a new transducer that he put on (right before he moved to Key West) - but now the display is approximately 90 degrees off - when the wind is 000, the display needle shows 270.



The Autohelm manual describes how to realign the instrument, but these factory instructions aren't recognized by the display head.



Any experience or advice? (Other than, of course, buy a new wind instrument, which is where I may have to go.)


Thanks in Advance


PlumBob

Hold down the Cal button for two seconds then use the arrows to adjust the wind direction. When it’s in the correct position, hold the cal button for two seconds to store the change.

[PlumBob]

Ssas5342, thanks for the reply. You've quoted the operation manual exactly, and this is the method I've tried several times.. The issue is that when I enter the correction, using the left/right arrows, the needle does not move, as the manual seems to indicate that it should, although the correction, in increments of 10 degrees, shows in the display. AND, when I press the Cal button for 2 seconds to store the change the change is not saved.



Any other ideas out there?


Thanks, PB

[jamhass]

Try the procedure for the ST-60? Maybe you got an in-between unit??
https://usermanual.wiki/Raymarine/Ra...555851736/html

[PlumBob]

Jamhass, thanks. I had already downloaded the Raymarine i60 manual. Thanks for the ST60 link.

My display head has only 2 buttons, each little rocker switches I think, whereas the newer displays have 4 buttons. Nevertheless, I'll certainly try this procedure..... However......


Rereading everything makes me realize that I did not do one of the "linerazation" steps - I haven't turned the boat through 2 complete circles to let the instrument figure out where north is. Duhhhh. I'll do that this week, and let you guys know.

Thanks to both of you.

[j.g.evans]

The old wind transducer is repairable. New SS ball bearings are available from McMaster Carr. There are only a few electrical parts with the Hall sensors being the critical ones. They are available too. They are on a ceramic cards that are easily broken. Be careful in taking the transducer apart.

I have been told that the ST 50 wind speed can't be calibrated and that the new Raymarine transducer will give an incorrect reading. (The ST60 Wind will work with the old transducer by calibrating the speed.)

[tilostahl]

Hi PlumBob,

If you get it to work, please report back. I've tried to recalibrate mine half a dozen times without any success, including doing the prescribed turns.

Tilo

[jamhass]

Here are a couple of very brute force ideas as a last resort if all else fails.

1. Mount the transducer sideways.
2. If you remove the feather, you will see the shaft has a keying flat on one side. Carefully file a new flat at the correct angle and fill the old one. Risky, But as a last resort?

[Riddle]

If you can get the unit of the mast, then try removing the vane. It’s a very tiny hex screw and a 3mm shaft. Pull off the vane off and rotate it 90 deg.

[jamhass]

Originally Posted by Riddle

If you can get the unit of the mast, then try removing the vane. It’s a very tiny hex screw and a 3mm shaft. Pull off the vane off and rotate it 90 deg.

The ST-60 vane shaft has an indexing flat. Can't "just" rotate the feather without modifying the shaft or the seat in the feather base.

[thunderhoof]

If the masthead unit is supplying data, but the heading function is sticky, the unit may be repairable by replacing the bearings. I believe that the masthead units are similar from many suppliers in that there are two ball bearing that allow the head to rotate.

Remove the screws that hold the wind vane/anemometer to the mounting rod and slide the sections apart. You should see the bearings. If they are discolored or rough to turn that is your problem.
My Nexus/Garmin unit was assembled in a diabolical manner that allowed the upper bearing (the OK one) to be removed but required the circuit board holding the Hall sensors to be removed to take off the lower one. This required unsoldering the board, a delicate task if you want to avoid damage to the board. At this point I would find a qualified electronics technician if possible. Otherwise, try the following:
The board on my unit slides out (after removing two screws) so about 2 inches of wire is accessible. I was able to cut each of the four wires, strip and tin each one, slip on heat-shrink insulation and do simple straight wire overlap solder joints after I replaced the XXX failed bearing.
The bearings are available from McMaster-Carr or Boca Bearing.
The reason my lower bearing failed was water leakage through the joint between the parts. The paper gasket there was insufficient so I put a light bead of silicone sealant around the outside of the joint.
Reassemble carefully making sure the Hall sensor is in the same orientation as before the repair.

...all in all a true PITA but $300 cheaper than a new masthead unit.

[SaltyMetals]

After 15 yrs my windvane was sticking, not picking up the wind direction and the speed reading seemed irregular. I disconnected the old unit and brought it down to strip it and get at the bearings. You can find some directions on YouTube for this. You can purchase a new bearing set but i just cleaned mine with generous amounts of WD40 and plenty of patience. I even found human hair in both the direction indicator and the anenometer so the prev owner must have had a young lady go up the mast to sort something out. (Always choose the lightest, right....)

So i got it all working smoothly, some new oil in the bearings, some vaseline in the joint to help keep the water out and remounted it and i think i remember a little drain hole underneath so if any water does get inside it has a way out. Make sure this hole is not blocked. When plugging back in at the top of the mast use some sort of electrical sealer on the terminals and some vaseline on the seal. The first thing to do is the linerization procedure. After that you might need to fine tune the direction indicator using the CAL setting. It is all in the book. I would clean up the old unit, oil it and put it away safely since i am sure it would happily give another 10-15 yrs of service.
Andrew
"Genial Bee"

[PlumBob]

Wow, Thanks everyone, for the insightful comments. Today is Friday 4/10, and we're taking the boat out tomorrow to do the obligatory "two slow complete circles" and just to get out of the house for a few hours. I definitely will report back.

The sensor, short-arm transducer, what-ever-else you might call it is/was New. And I've disposed of the old one (sadly) which is not my usual habit of saving nearly everything LOL. This is the only instrument that I didn't replace in 2014, when we moved the boat from Montana to Florida (she spent most of her life on Puget Sound.) Just last night, I found documentation that I have that shows that the Autohelm ST50 is the original wind instrument from 1994. I really would like to squeeze another few years out of it, if I can - as opposed to shelling out $500 for a new Raymarine display - and I don't know at this time if the old cabling between the transducer and display is compatible with a new display. Nor if I could plug in new cabling to the existing transducer mount at the masthead.

Ahhhh, well..... I'll talk to you all tomorrow evening. Hopefully I'll have good news.


PB

[PlumBob]

OK, so here's the deal.

No joy! We did 5 complete circles to port, and 4 to starboard. The instrument did Not align itself. It is semi-consistently 90 degrees off - the instrument pointing 270, when the wind is at 360.

The "semi-consistently" comes from the fact that during the circle, the pointer does in fact come to point in the same direction as the wind, but as soon as it gets there, the pointer backs up 90 degrees.

I did try (once) to put in a manual adjustment, as per the procedure - it appeared that the needle was moving in the correct direction, but as soon as I took the instrument out of the adjustment/calibration mode, it went right back to being 90 degrees out.

Thanks to all of you for your thoughts and comments. I'll get back if I ever get this thing to work - but I'm not hopeful.

Thanks Again

PB

[dougweibel]

I don't have Raymarine anymore so my memory may be faulty but my recollection is that there are two signal wires and the voltages operate in quadrature phase. It would seem to me that if you are 90 degrees off the signals may be reversed. I don't see how that could have resulted from replacing the transducer at mast top but it may be worth a try to swap the signal wires and see what happens.