Good/Best Tiller Autopilot

[seandepagnier]

It is possible in theory to design a wind vane that steers to true wind, or an adjustable combination of true and apparent. It needs a mechanism to put force on the vane based on the water speed.

I haven't figured out a good way to do this, just noting that it is possible.

It is also possible to use a spinning gyroscope (using relatively small electric motor, or even possibly wind power) connected to the linkage to straighten course reducing or even preventing the typical S over steering downwind every windvane makes. It would be really interesting to use an air propeller here since the result could remain completely mechanical.

[wingssail]

Originally Posted by Jim Cate

Fred, do you have any issues with the Monitor when sailing deep angles in surfing conditions? The apparent wind goes forward pretty quickly when our boat takes off on a wave, and I've worried about control with an apparent wind-driven steering mechanism.
Jim

I ran some numbers.

Example:
Wind from 60 True at TWS 23 kts
Sailing due west HDG 270, TWA 150, AWA 137, AWS 16.8
Optimum boat speed 7.65kts

Big wave comes, boat surfs up to 9.65kts
Now AWA = 132, AWS 15.4
Wind vane will try to drive you down 5 degrees but some of this will be lost by boat yawing as the wave lifts the stern.

Big wave comes, a different boat surfs up to 12 kts
Now AWA = 125, AWS 13.2
Wind vane will try to drive you down 13 degrees but some of this will be lost by boat yawing as the wave lifts the stern.

Big wave comes, a much different boat surfs up to 15 kts
Now AWA = 115, AWS 12.7 Wind vane will try to drive you down 23 degrees Yahoo!

If you are sailing deeper, AWA will change less.
If you are sailing higher, AWA will change more.

[Snowpetrel]

Originally Posted by wingssail

I ran some numbers.

Example:
Wind from 60 True at TWS 23 kts
Sailing due west HDG 270, TWA 150, AWA 137, AWS 16.8
Optimum boat speed 7.65kts

Big wave comes, boat surfs up to 9.65kts
Now AWA = 132, AWS 15.4
Wind vane will try to drive you down 5 degrees but some of this will be lost by boat yawing as the wave lifts the stern.

Big wave comes, a different boat surfs up to 12 kts
Now AWA = 125, AWS 13.2
Wind vane will try to drive you down 13 degrees but some of this will be lost by boat yawing as the wave lifts the stern.

Big wave comes, a much different boat surfs up to 15 kts
Now AWA = 115, AWS 12.7 Wind vane will try to drive you down 23 degrees Yahoo!

If you are sailing deeper, AWA will change less.
If you are sailing higher, AWA will change more.

Thanks for the numbers, really brings home the issues with surfing and windvanes. Glad to hear my very similar design should behave under windvane and not surf erratically.

Originally Posted by boat_alexandra

It is possible in theory to design a wind vane that steers to true wind, or an adjustable combination of true and apparent. It needs a mechanism to put force on the vane based on the water speed.

I haven't figured out a good way to do this, just noting that it is possible.

It is also possible to use a spinning gyroscope (using relatively small electric motor, or even possibly wind power) connected to the linkage to straighten course reducing or even preventing the typical S over steering downwind every windvane makes. It would be really interesting to use an air propeller here since the result could remain completely mechanical.

The Early days of the OSTAR singlehanded race across the atlantic produced some wild experimental wind vanes. As I recall at one stage Pen Duick II had a wind driven gyroscopic stabilizer, but the precession on different tacks was an issue. Look at pg 88 here about the Gumnop mechanism for more details

https://www.ayrs.org/repository/AYRS013.pdf

[thomm225]

So I finally reassembled my Simrad TP10 Autopilot that I thought I blew up by cross wiring.

I took it down to the boat today and hooked it up directly to the battery and it worked.

I tried this before but with no luck.

Now I have two working autopilots which is really good news. Now all I need is a new plug for the Simrad

[wsmurdoch]

My Simrad autopilots use Bulgin Standard Buccaneer connectors.

https://www.mouser.com/datasheet/2/5...ndard-3651.pdf

I have bought replacements from Mouser.

Bill

[thomm225]

Originally Posted by wsmurdoch

My Simrad autopilots use Bulgin Standard Buccaneer connectors.

https://www.mouser.com/datasheet/2/5...ndard-3651.pdf

I have bought replacements from Mouser.

Bill

Thanks, they look like good connectors, but I have already installed the Raymarine ST 2000 I bought as a replacement with the plug that came with it.

I guess I'll have to buy a matching connector to the Raymarine type or solder on a longer wire with alligator clips as a backup

[seandepagnier]

Originally Posted by Snowpetrel

Thanks for the numbers, really brings home the issues with surfing and windvanes. Glad to hear my very similar design should behave under windvane and not surf erratically. The Early days of the OSTAR singlehanded race across the atlantic produced some wild experimental wind vanes. As I recall at one stage Pen Duick II had a wind driven gyroscopic stabilizer, but the precession on different tacks was an issue. Look at pg 88 here about the Gumnop mechanism for more details

I thought about this. A gyroscope could allow a windvane to react faster. Would it be possible to drive the gyro from a small electric motor? I know this is "cheating" but wind vane would still work without power in the normal way.

A wind driven gyro is the ultimate of course, but difficult to do well. The blades need to be large to work in light wind, and the boat motion throws it from gyroscopic effects. I'm not sure if the gyro flywheel and wind blades should be in the same axis.

https://www.ayrs.org/repository/AYRS013.pdfAttachment 179482Attachment 179483

Originally Posted by thomm225

So I finally reassembled my Simrad TP10 Autopilot that I thought I blew up by cross wiring.

I took it down to the boat today and hooked it up directly to the battery and it worked.

Maybe it "works" but the simrad tillerpilots aren't a very efficient linear actuator (20-35% efficient) and also work much better using an autopilot with actual gyro sensors. A gimbaled fluxgate like that doesn't work very well once it is swinging around.

The power consumption is less than half, and much less in very light air. The course steered straighter reduces chafe on sails as well as giving a faster overall speed. This is using simrad tp22 as a driver and pypilot.

[thomm225]

Originally Posted by boat_alexandra

Maybe it "works" but the simrad tillerpilots aren't a very efficient linear actuator (20-35% efficient) and also work much better using an autopilot with actual gyro sensors. The power consumption is less than half, and much less in very light air. This is using simrad tp22 as a driver and pypilot.

If I start sailing longer distances, I'll have to check into a more efficient tiller pilot maybe, but for now with most of my weekend/vacation sailing trips being in the range of 60-150 miles, I'll continue with the Raymarine and use the Simrad as backup...........unless I find time to experiment with the pypilot setup

[CarinaPDX]

@thomm225: I have a set of the Raymarine connectors if you want them. Personally I don't like them - The Bulgin Buccaneer connectors are superior IMHO. PM to arrange.



Greg

[andyful20]

Originally Posted by hpeer

I’ve had lousy luck with RM 2000 AP. The rubber bits inside disintegrate and fall into the “cup” holding the gyro and jam it. One failed within 24 hours of return from factory repair. I have 3 of these buggers and just bought a Peligic. I’ve nust received the Peligic and not used it yet but by weight and visual observation it’s Tonka vs. Caterpillar. No, not fair, actually Tonka is made of metal.

Failure history
1 Rubber thrust bearing (?) disintegrated after about 150 hours of use. Jammed gyro.
2 Brand new replacement with bad gyro out of box
3 second brand new replacement with bad gyro out of box
4 Repaired unit failed at about 80 hours when rubber 0 rings around stabilizer rods broke apart and jammed gyro.
5 Repaired unit failed after under 24 hours use. Not certain of failure mode, intermittent, but O rings and other parts were deteriorating and I found a small bit of rubber under the gyro.

The units we driving either a servo pendulum vane (nearly 0 force required) or driving the tiller on an aux rudder wind vane system with normal loads.

I have been able to disassemble, clean, and swap parts to make them work. If you don’t get them together just right they are subject to water intrusion. I’ve left off such failures.

HI--ARe you refering to Pelagic Pilot or the others in reference to damage?thanks-

[hpeer]

It’s the RayMarine APs I’ve had trouble with.

I’ve now bought a Pelagic and installed it but have not used it yet, in a week or two. Just superficially the Pelagic looks and feels head and shoulders better than the RM. The only apprehension I have is how the compass will work on this steel boat. Pelagic does allow me to mount the compass in a better position and use a wireless remote. So I’m optomistic.

[ABJ87]

Originally Posted by Standbly

My boat is not within specs limits of an off-the-shelf Ray or Simrad tillerpilot. So I configured something myself. It's basically an ST4000+ boosted with an H-bridge amplifier and a type-1 linear motor from Ray. I sealed the type-1 to be watertight and it's above deck. It does the trick.


I'm dependent on it, I do not have a windvane and I've crossed the Atlantic with this setup.



(yeah I know, a windvane is safer, better, etc but my boat has the wrong ass for a windvane and the final decision was to go with an electric system and a backup electric system)

What are you using for a H bridge amp? I have a similar Franken-pilot, ST4000+ driving a gutted ST2000 tiller pilot.

It works well but the ST4000's tend to fry MOSFETS if pushed too hard, so i would like to have an external device do the motor driving.

[gulfislandfred]

Years ago, I saw an ST 1000 rigged on the trim tab of a windvane type self steering. The ST1000 hooked to the linkage that would have connected the small sail at the top of the vane. Very small force on the trim tab would move the rudder.

[boatnerd]

We use an older modified Hydrovane connected to an ancient Tillermaster from the 70s. They work surprisingly well together and use very little amp hours. Tillermasters are ingeniously simple and use high quality components. Not very powerful but very reliable and easy to fix. Secondhand they're usually really cheap if your lucky enough to find one. I rarely use our ST4000 wheelpilot anymore and store it below out of the salt n sun. Even though it doesnt have the latest circuitry it's amazing how well some of the old stuff works.

[DavidWW1]

First, thank you, contributors, for all the advice and information here.

I have a Raymarine ST2000+ that's about four years old, and it seems to work as it should, but... the first year after a couple of hours of motoring our C&C27 at moderate speed in flat water, it developed a crack on one side of the upper casing. I fixed this with epoxy and that seemed fine (but I didn't use it for two years). Last season, I used it for three or four hours, flat water, with no wind so motoring, and I later noticed it had developed more cracks in the middle of the casing, upper and lower. Interestingly, it looks as though these cracks were formed by twisting, rather than impact or simple pressure.

Raymarine claim they no longer have replacements for the casing, so I took it to a plastics supplier. A rep there told me that a) that this plastic gets really brittle with age and b) it's really hard to bond to, so forget about repairing it with epoxy or polysulphides (someone in a marine store suggested G-flex, 5200 or Gorilla Glue, but this fellow claimed that these will give a temporary bond that won't last).

So, the short term option is that I ask if anyone here has a unit whose internals have perished, but whose casing is intact. If so, please message me (see the FAQ if you've not done this before - I mention this option because I haven't) with your terms. Parcel post would be to Toronto.

Thanks for reading this far.