wind direction indicator for auto pilot

[reastmure]

I've been trying to find a mast top mounted wind direction indicator so I can enable the auto angle feature on my raymarine wheel pilot. Has anyone done this and what products are out there that would work for this? (without spending thousands of dollars hopefully)

[Dennis]

See if this may be of help. The unit will be available later this year. Here is a link to the website: http://www.flyorsail.com/

Dennis

[reastmure]

See if this may be of help. The unit will be available later this year. Here is a link to the website: http://www.flyorsail.com/

Dennis

Hey thanks Denis! Very cool looking set up. Just have to get the courage up to fork over the $900. to get one.

[mastreb]

$900 is what most anemometers cost, and this is the only unit in the world that cancels out the rotating mast effect. Your other option is to mount it on a pole on the bow (which is what I do) but it doesn't look great.

Matt

[kurz]

or this?
http://www.sailtimerwind.com/

if the price stays looks interesting. No hassle with installing cables and mast rotating sompensating things. For the autopilot you will need an interface to catch the signal I guess...

[beene]

I just installed this last summer for my Raymarine Autopilot

http://www.westmarine.com/webapp/wcs/st ... sNum=50173

Works great
Seen here in my videos

http://youtu.be/8aJQdl6Pu3M
http://youtu.be/JzpxJy-EpgU

[BOAT]

I am not seeing where either of these solves the problem of the rotating mast.

Beene, your instrument sounds very interesting - i will look at your movies now - I thought you sailed a MAC x and it was your friend Highlander that had the M ??? Are you using a rotating mast??

[beene]

I am not seeing where either of these solves the problem of the rotating mast.

Beene, your instrument sounds very interesting - i will look at your movies now - I thought you sailed a MAC x and it was your friend Highlander that had the M ??? Are you using a rotating mast??

bought my M new in 2006

The instrument I use would not matter where you put it, rotating mast or not, it shows apparent wind angle and speed ref to autopilot computer information provided from the network.

It is ref your boat heading, not which way the mast is pointed.

G

[BOAT]

Let me digest this - you have a wind indicator that works with the rotating mast and it's LESS than 500 bucks . .?

So all the people here that have been trying to solve this problem for years had a better answer right there all along? The cheapest we could find was 900 bucks.

If I am going to get a Ray Marine Autopilot anyways then why not also use a Ray Marine wind indicator that works no matter what way it's pointing??!!??

Beene, your a genius!

So what does the wind part look like? Is it a birdie with cups and stuff or is it an electronic thingy?? I suppose it only works when you are moving forward (and who care because an autopilot only works when you are moving forward too!)

More details please! I think you have answered my wind instrument troubles Beene! (I owe you a Scotch or Wine - your choice)

[mastreb]

The Raymarine i40 rotavecta does require linearization calibration to determine its heading and will report inaccurate wind direction with a rotating mast. The linearization calibration process is described in the i40 installation guide, and it very specifically is determining the mounting point heading line.

You WILL be able to weathervane with it using an autopilot because you can weathervane with a completely uncalibrated wind instrument or one that is not linearized--It doesn't matter if the wind direction is "correct" when you weathervane, it only matters how it changes relative to your tack, and the MacGregor mast tends not to move around much on a tack.

But the instrument will not report correct wind angles compared to heading on a rotating mast.

[kadet]

I am not seeing where either of these solves the problem of the rotating mast.

Beene, your instrument sounds very interesting - i will look at your movies now - I thought you sailed a MAC x and it was your friend Highlander that had the M ??? Are you using a rotating mast??

bought my M new in 2006

The instrument I use would not matter where you put it, rotating mast or not, it shows apparent wind angle and speed ref to autopilot computer information provided from the network.

It is ref your boat heading, not which way the mast is pointed.

G

Sorry Beene that is not really the case as part of the calibration process for the i40 wind is to turn your boat in a slow circle with no wind this is so the vector and computer can define it's orientation to the boat, that preset orientation is a constant whereas the rotating mast is variable and will not remain the same as the preset constant used in calculating wind angle. This is the same for all wind instruments they need to know their orientation to the boat to accurately calculate the angle (apparent) they then need a boat speed input to calculate true. If the orientation is variable they need a third input mast angle to accurately calculate the actual angle.

The rotovecta has one cup with a tab this cup is driven faster downwind and slower upwind than the other two, so the rotation speed is not constant. The position as you said depends on apparent wind direction so it can be analysed to derive wind direction once the orientation to the boat is know. This orientation is not taken from the heading but from the preset done during calibration. This just replaces the vain used in other instatements.

As to how much effect this error has on a mast that is already pitching healing and otherwise not remaining constant is another matter.

I looked at many solution when I was fitting my wind instrument including the rotavecta. I went with something else but I mounted mine on a short pole at the rear of the boat (trailer a lot so did not want a mast mount) another no no as the wind instrument is supposed to get disturbed air from the main sail and give inaccurate readings. Never had a problem in 5 years sailing on all points.

If yours as mine works who cares.

[BOAT]

Hi Kadet ,

Beene's friend Highlander also uses his wind instrument on the rear of the boat - and I sort of wanted to do the same but my friend mastreb does not think it will make the autopilot work real well with the wind instrument on the back. Mastreb is about 200 points IQ higher than me so I'm really really wary to ignore his advice.

Are you using an autopilot in sail and wind mode with your setup?

I must rely on you guys because I'm sort of old school and nor really up on the latest "electronic" sailing equipment.

I sure would be interested in hearing from someone that is using the "Sail to Fly" instrument.

[mastreb]

Kadet I've gone to a bow pulpit mounted windvane on an 8' shakespeare pole + 2' SS extension on a rail mount. I mount it on one of the forward pulpit stanchions and then tie it to the rail, which is pretty sturdy.

I did this because I clearly was getting very incorrect readings on a beam reach when the mainsail dumped air into the instrument. If you try to weathervane an autopilot on these incorrect readings it will turn your boat suddenly when the wind shifts.

On a bow mount, it's forward of the genny about 3' and out of its aerodynamic influence, so its only incorrect when running directly downwind wing-on-wing. On that point of sail I don't need to know where the wind is, so it's okay, and when running you don't really need much wind information.

[kadet]

My pole forms part of my davit mount and extends about 1 metre about the s mast crunch on the starboard side and at a rearward angle which ends up back about midway along the motors cowling. As I said I was worried about interference from the main and was willing to move it if it proved a problem to date this has not accrued. I use my autopilot in all modes, from track, steering a fixed heading to steering a wind angle. The only time I ever had a problem was while under power, steering a fixed heading when the thing went crazy ivan and steered all over the place. Course computer had locked up due to a faulty power connection . Never had a problem since then on any point of sail. I have no doubt the disturbed air is causing some interference but not enough to affect it's performance with the angle of the pole and the cut of the sail the vane is a good 2.5 metres from the leach of the main at its closest point, in strong winds with a reef even further. I just don't think our little mains produce enough disturbed air to reach back that far with enough force to cause a problem. If you have muscle head or a roachy main then that could be a different story.

[mastreb]

Mine was mounted to the mast arch about 10' up, which I'd thought would be high enough to be out of the wind, but for my purposes (developing accurate polars) there was too much wind disturbance on a starboard beam reach. At all other points it was accurate.

Mine is not permanently mounted because I've not "committed" to any location yet. Still working on the simplest way to de-rotate a mast-top mount.