Autopilots, favorites, dynamics, boat type ?

[brianb]

What is your AP experience ?

What do you use ?

How does it handle downwind with the kite ?

Wind speed limits at what angles of sail ?

Boat type ? Full keel ? Fin Keel ? Sport Boat ?

What AP would you use if you could make a new choice ?

thanks,

brian

[tiger beetle]

Hi Brian -

Beetle has 3 self steering systems - monitor wind vane and two independent below-deck electric autopilots.

The wind vane is great for upwind and reaching, not so good for running deep under spinnaker, especially if the boat surfs. Each surf event results in the wind shifting forward and the vane sees this as a wind shift and puts the bow down, resulting in some wild deep sailing going into a round down. So I don't use the vane much for sailing under spinnaker.

The pilot I like the most is the Alpha Spectra running their linear electric ball screw ram (I have the 'ultraquiet' drive which uses plastic balls and very quiet, as compared to the same ram using steel balls - more rattly and noisy). The pilot has 3 controls: compass gain, yaw gain, and I added the 3-axis 'rate gyro' which helps the compass greatly when running quartering and following swells.

The backup pilot is a Comnav NX2 using the 1500 commercial head and a hydraulic ram. This pilot is noisy, makes a noise like a big snoring bear in the transom (GRRRRRR. GRRRRR), is strong, and I don't like it very much because it seems fairly stupid and noisy - but, it works through anything.

A feature I do not have, which I really want in the next pilot, is the ability for the pilot to steer to dampened true wind angle. I'm planning to re-instrument the boat in the future and am likely to purchase NKE and their gyro-pilot - this is the unit the Vendee boats are using. Looks to be good stuff. I'd like to add that Mark's Alchera (J-120) has a B&G Hydra pilot that has done several Hawaii races and Mark does well with the pilot. The Hydra pilot in his setup will steer to dampened wind angle, which is very helpful when the wind is 10-16 knots and shiftng 30 degrees every 20 minutes in mid-ocean. I was up and down poking at my pilot to keep adjusting course, his did that automatically.

The max winds the pilots have steered in are 50 knots on the beam, 18 foot breaking seas on the Newport 33 - the Alpha Spectra worked fine. That same pilot was transferred to the N/M 45 and it has seen 45 knots for several days winds on the beam, 16 foot seas (not breaking). The ComNav steered well inbthe same conditions. I have broken several above-deck Autohelm pilots on various boats, my favorites are an Autohelm 4000 wheel pilot that ground itself into dust over several days after the gearing between the motor and the drive unit failed to correctly separate, and an Autohelm 3000 in which the little internal fluxgate compass broke free of its mounting and was rolling around inside the case - made the boat go all over the place!

As regards experience under pilot, I've done 3 singlehanded transpac with the alpha, two with the comnav also on board, and have had failures in all races. Carry a spare ram (mininum) for each pilot, plus a boxful of fuses and any other breakable parts. Also lots of local ocean miles - 25,000 in big beetle (N/M 45) and about 15,000 in little beetle (Newport 33).

Both boats are moderate displacement fin keel masthead rigged boats.

Hope that gives some food for thought.

- rob

[John Hayward]

Hi Rob,

How do you generate enough power to run the electric autopilot all the way to HI?

50 Kt winds and breaking seas in a Ranger 33? That must have been an E ticket ride. Bare poles or trysail at that point?

John

[tiger beetle]

How do you generate enough power to run the electric autopilot all the way to HI?

The basic charging circuit is the Perkins 4-108 diesel engine driving a 105 amp hot-rated alternator, controlled via an Ample Power 3 step regulator. To observe the charging there's an Ample Power Energy Monitor II. I typically plan to run the engine twice a day, one hour each morning and evening, during the radio check-in on SSB. Has worked out quite well.

For back-up/alternate charging I have an Airx wind generator and 120 watt Kyocera polycrystalline solar panel set up on a stern-mounted 'H' frame. The wind generator works great in the string winds while reaching off the coast and basically powered the entire boat for the first 3 days of 2006; once the wind shifts aft and lightens (the trades) the wind generator doesn't do any work. However, the solar panel does kick out 4-5 amps most of the time it's sunny, and supplies more than enough power to operate the small refrigeration compressor and the laptop computer.

Between the wind generator and solar panel, I only had to run the engine 1/2 as much as I had to in prior races. Which was nice.

50 Kt winds and breaking seas in a Ranger 33? That must have been an E ticket ride. Bare poles or trysail at that point?

Actually it was quite ugly, and it was a Newport 33 (not a Ranger). I was coming in from offshore half way through my TransPac qualifier in November, and it had been very windy offshore for several days, 25-35 knots, big seas, lots of white caps, everything was going well if a little uncomfortable. Unfortunately, the NOAA forecast failed to pick up the '55 knot uppper level disturbance' (as NOAA termed it in their later broadcast later that night) - the forecasts continued to call for gale conditions, but nothing worse than that.

I was 30 miles west of the Farallons, sailing east, and it started to howl and the seas stood up and started to break - it was wild. It was o'dark 30, perhaps 11pm through to 4am that it was that windy, bright crispy clear sky, tons of stars, the moon was out a bit, and you could see everything quite clearly. I had up 3 reefs in the main and the 85% jib and we were zippiting along. I decided at that point to head for Drakes Bay and hide out there in the lee of the Pt. Reyes. The seas were huge, and I would stand in the cockpit whilst hanging onto the primary winches and look around - dotted around were giant cresting, tubing waves, just like on the beach, with enormous tumbling walls of white water spreading off to either side of a breaker - perhaps a half mile of open space between breakers.

So I kept on sailing, the autopilot was driving, I mostly just hung on and watched - didn't feel like there was a heck of a lot I could do other than carry on and consider steering around a breaker, only they rear up so quickly and equally suddenly disappear that there didn't seem to be a lot of percentage in trying to avoid one - either the wave will hit you or it won't. So I mostly stared at the ocean, these were conditions I hadn't seen before and it was a really impressive sight. A number of times a wall of tumbling white water six feet high slide down from a wave crest would wash entirely over the boat - the water was very aerated and not that heavy, so I'd be waist deep in swirling water in the cockpit, and looking forward all you'd see of the boat was the mast poking up out of the foam, no boat to be seen anywhere, then the hull would rise up and the white water would slide off.

After a couple hours of this (I was down below by now), a wave must have crashed onto the boat as there was an almightly BOOM! and the whole boat twisted. At that moment two of the engine mounts broke free, the prop shaft was broken at the transmission coupling, and the nav station window (safety glass) cracked. A whole lot of other stuff went wrong too, but those were the major ones and a whole bunch of water squirted in through the wash boards and flooded out the galley. I poked my head out the companionway to see if the mast was still up, and it was - so I looked around for ships, then went back down below to try and figure out where I was and see if I was still going in the right direction. Took at least one more big hit from a breaker that did more damage and cracked the window further but the glass didn't actually fail completely - that would have been a real bummer as I would have had to get on deck and hammer a piece of plywood into place (which I had on board, but I hadn't realized how difficult it would be to attach the plywood to the cabinside in those conditions).

It was a lot nicer when I got in behind Pt. Reyes - the seas dropped off considerably. The wind also dropped down to the initial conditions as the disturbance had moved on. At that point I was really tired, I had lost my charging system (the motor), and I was completely soaked and so was the boat, and I was only half way through my qualifer - I was no longer interested in going back out another 200 miles through the gale to finish the run. Instead I went to Sausalito, anchored out, and got a great night's sleep. Took me three months to fix the boat and get little Beetle up sailing again.

- rob

[haulback]

Boat is an Spencer 35, tiller steered, full keel/cutaway forefoot, narrow with longish overhangs (25 ft @ W/L) 12,000 pound design displacement (14,000 on scales - with fuel, water, ground tackle etc. No food, spares or provisions)

Primary self-steering is a Fleming 501 servo-pendulum windvane that has given good service since installation. My AP selection initially was for something to steer only when the windvane is less than optimal, ie: motoring and low apparent wind speeds. I chose a Raymarine ST4000+ tiller pilot, and it sort of did the job, but unless conditions were ideal it spent a lot of time on either side of desired heading and precious little on course. That being said, it has given good service over last 5 years, considering the boat is right at the top end of it's performance range.

I decided after this last trip to try to do something about my AP situation. After looking at various options (due to lack of room, and inaccessibility it is not practical to mount a belowdecks ram anyplace where I can get at it easily to disconnect it when not in use) I decided on a raymarine SI GP tillerpilot. This unit comes with a built in rate/gryo in the course computer, and being rated for boats to 16,500 lbs, seemed like it just may do the job. Local sea-trails with it proved successful in winds up to 20 knots but it's hard to simulate running downwind in an ocean swell when sailing in Georgia Strait. The rate/gyro signal getting to the ram seemed to be fine, I was impressed that it kept the boat almost dead-on track. But must admit I question the longevity of the SI GP ram having to drive the boat under continuous use for days on end during the SHTP.

Then got to wondering how I could use the course computer to power a bigger drive (this end of it looking like the 'weak link') . I just happened to have a used but operational Raymarine Type 1 linear drive electric autopilot laying around, and sat in the cockpit for a couple days with it in my hands considering various options.

S1 drive is 185 lb max thrust - Type 1 800 lbs... both want 12 volt input, both motors work by reverse polarity

To make what is looking like the beginning of a very long story somewhat shorter - I've arranged it so the the Type 1 drive can be bolted on deck, and I welded up a removable short tiller arm bracket that fits on the existing tiller-head fitting. This worked well enough during initial sea trial to go to the next step.....which is...

The S1 GP course computer is fused at 10 amps for it's drive unit, but the Type 1 drive wants 25 amp fusing because of it's bigger motor and greater thrust. Figured there must be some way to use the 10 amp Course computer signal to excite a separate 25 amp output to the Type 1 drive, supplying max power as req'd. Talked one of the radio/electric guys at work and he is putting together a box full of relays, contacts and god-knows-what-else, that will do this.

I won't get to do a full sea trial on it of a couple of months yet, but I see no reason why it should not do the job.

Reality of it is. that the big drive is for single purpose use only, that being for going straight DDW under twins in the SHTP. Certainly for normal sailing what I had previously has served me well.

Anyone use out there using a SI GP tillerpilot with a rudder reference unit hooked up to it??? Does it make a whole lot of difference????? I have one and wondering if I should incorporate it into set-up......

Jim/Haulback

[SSSForumAdmin]

Rob, that's a grim story...your Little Beetle story about taking the hits that cracked the windows.

Anyway, on Ankle Biter (SC27) I use an autohelm 2000 and a Navik Windvane. Note that I"ve only owned the boat for 6 months, tho, so I'm no expert \, yet. I've not tried the windvane with a spinnaker, yet. The 2000 will handle the boat with a spinnaker in under 15 knots, above that, all bets are off. However, it will drive the boat quite happily under the kiteship kite, at least for about half an hour, in 15 knots of wind, but that's all I've tested it in.

I'm a serious windvane fan. They don't burn electrons and they steer the boats...this Navik steers the Santa Cruz 27, my Santana 3030, and my old Ranger 29, just great in all conditions including wing and wing, downwind. ditto, if the spinnaker is up under 12 knots.

If I could have ANYTHING, and forget the money, I'd probably get an NKE control head, an apparent wind angle indicator and set it up to drive an autohelm 8000 tiller unit....or something like that.

[AlanH]

Rob, that's a grim story...your Little Beetle story about taking the hits that cracked the windows.

Anyway, on Ankle Biter (SC27) I use an autohelm 2000 and a Navik Windvane. Note that I"ve only owned the boat for 6 months, tho, so I'm no expert \, yet. I've not tried the windvane with a spinnaker, yet. The 2000 will handle the boat with a spinnaker in under 15 knots, above that, all bets are off. However, it will drive the boat quite happily under the kiteship kite, at least for about half an hour, in 15 knots of wind, but that's all I've tested it in.

I'm a serious windvane fan. They don't burn electrons and they steer the boats...this Navik steers the Santa Cruz 27, my Santana 3030, and my old Ranger 29, just great in all conditions including wing and wing, downwind. ditto, if the spinnaker is up under 12 knots.

If I could have ANYTHING, and forget the money, I'd probably get an NKE control head, an apparent wind angle indicator and set it up to drive an autohelm 8000 tiller unit....or something like that.

This post is by me, obviously since I'm the forum Administrator...

[brianb]

Hi All,

Thanks for the feedback. I have just about purchased an NKE twice in the last year but wanted to rule out the Raymarine S1G. My research indicates there are only two competitive helms out there, NKE and BandG, these guys together own the ocean when it come to racing Open 60's to Mini Transats.

Am leaning toward a homebuilt hydraulic drive and either the NKE or Raymarine. The later to just save dollars. The drive units are priced out of this world. It appears to me I can save about $1500 by selecting a Hydraulic cylinder and pump as opposed to the canned solution that is shipped with everyone's electronics.

Good to hear about what everyone is using.
Brian Olson 34

[John Hayward]

Hi Rob,

Thanks for the charging info and the story of the qualifying run. Ugly indeed!!!

I figure I am going in the hole about an hour a day or a little more without the solar panels. My qualifying run (down to Santa Cruz Island) took 4 1/2 days and I ran the engine once for about 2 hours (in neutral). I have 6 110amp Hr batteries. I didn't use the electric autopilot at all the entire time, just the monitor. I was close hauled until just North of Pt. Conception and then the wind shifted and and I ran around Conception. I had about 30 Kts coming around Conception and some of it was DDW and the Monitor did just fine with the small paddle. In lighter conditions going DDW it does fine, but I have to use the larger paddle. I never got to use the solar panels, hardly saw the sun until I was at Santa Cruz Island. I would rather not run the engine twice a day for an hour if I can avoid it and it throws a lot of noise into the HF in addition to just the engine noise itself.

What do you think about the tow behind generators? There is one that you can use as a tow behind or you can put wind blades on it and use it as a wind generator. The either/or seemed pretty cool?

Thanks,
John

[tiger beetle]

I didn't use the electric autopilot at all the entire time, just the monitor. I was close hauled until just North of Pt. Conception and then the wind shifted and and I ran around Conception. I had about 30 Kts coming around Conception and some of it was DDW and the Monitor did just fine with the small paddle. In lighter conditions going DDW it does fine, but I have to use the larger paddle.

For purposes of *racing* to Hawaii, a monitor wind vane is slower than an electric pilot simply because the monitor steers the boat to follow the wind shifts, which means you sail more miles under the vane than you will under electric pilot that keeps the boat pointed straight down the track. The gain in miles sailed towards the finish comes at the expense of trimming sails to follow wind shifts, plus you have to keeping charging the batteries.

For the sail back from Hawaii, the monitor vane is a great tool as it can be set up and will keep the sails trimmed all day long so you can go off and read a good book and keep an eye out for pelagic critters. So I don't use the monitor at all enroute to Hawaii, and use it for much of the sail home.

It would be a good idea to work out how to recharge the batteries and keep feeding electrons to the pilot, and having the vane provides a solid backup self-steering system.

I never got to use the solar panels, hardly saw the sun until I was at Santa Cruz Island.

Don't write off the panels just yet. The marine layer / high clouds will often extend from the coast some 5-600 miles to the ridge , and the clouds pretty much kill the solar panel output. Once you are into the ridge and subsequent 1000 miles of tradewind sailing solar panels work well. They're just so not useful right off the northern California coast.

I would rather not run the engine twice a day for an hour if I can avoid it and it throws a lot of noise into the HF in addition to just the engine noise itself.

If the engine is throwing RF noise into the HF radio, then there's some work to be done on the alternator side of the house. Mike Jefferson is a good one to talk with regarding RF noise attenuation.

QUOTE=John Hayward;114]Hi Rob,
What do you think about the tow behind generators? There is one that you can use as a tow behind or you can put wind blades on it and use it as a wind generator. The either/or seemed pretty cool?
[/QUOTE]
Tow generators are a great idea, water is approximately 800 times more dense than air and you can extract a lot of energy from the boat's forward motion by towing a propeller that spins in the water, even at slow speeds. Unfortunately the energy you're extracting is stolen from energy that should be moving you towards Hawaii - the tow generator slows you down considerably. You might only use it a few hours per day, but for those hours you're slow. I would consider a tow generator a good backup charger, but not the best primary charge source for a race.

The other downside to the tow generator is you have to be moving for it to work. When you're not moving then solar panels and engine charging fit the bill.

I approach charging for purposes of Singlehanded TransPac (and assuming you already have an inboard engine) by playing to the boat's strengths and beef up the motor charging circuit first such it will completely power the systems, and if you have time/money/room on deck then add charging circuits that can supplant some (but unlikely all) of the needed power. Solar is good and simple, wind generators are ok but more difficult to mount, a second gas-operated charger has it's own problems plus you have to carry gasoline, and a tow generator is viable as an emergency/backup power generator when all else fails and the boat is still moving.

- rob