Autopilot failure on long passage

[stormalong]

I have two autopilots on a very complex switch to a common Autohelm type 2 mechanical drive. The switch selects which course computer gets power and switches the clutch and motor wires.

The drive is connected through a four pin generator connector. The clevis pin that mounts it is held in by stainless steel hitch pins.

So, if a course computer or one of it's components fails I can use the switch to change to the alternate course computer. If the mechanical drive fails I can swap it out for a spare in about 15 minutes. I have swapped the drive at sea with the wife at the helm. If I was a solo sailor I could heave to to change the drive. Can catamarans heave to?

I would not want a second drive permanently installed because there are moving parts that wear even without it activated and I don't want the additional mechanical load.

[goboatingnow]

Originally Posted by thinwater

I have had that problem off-shore, several times. I fixed the pilot, but meanwhile you have to do something.

Adjust sails (jib in, main out, reef the main as needed) until the plan is balanced. Lock the rudder. Works on some windward and reaching courses. Sail jib-only. Works downwind. Both are slower. Both of these are best practiced before you need them. I learned these before I had a tiller pilot.

Bungee steering never worked on any cat I have owned.

Drift to rest.

Other than that, spares, obviously.


Failures will be MUCH less common if you balance the boat so that the pilot is not working as hard. We tend to forget that. A small drogue can help in rough weather, not for survival, but to ease the steering load.

I agree re balance

I spent an interesting afternoon sitting in the repair area of my local raymarine dealer ( Pharos marine) the tech guy there is very capable and he showed me various failures on Ray marine linear drive abs jefa drives ( which I have ). He certainly convinced me of the repair-ability of the 2nd gen Ray marine drive

I think these days carefully maintained and a reasonable balanced boat an electric AP will happily cross oceans without incident and even then some are easily repaired.

( the jefa ones being more vulnerable then the raymarine)

It’s always great to spend an hour or two chatting and helping the repair hours as you find out what’s actually causing issues.

Hence for raymaribe arms a gearbox spares kit for jefa linear arms , you need a clutch ring and clutch pin as these are what failed it seems.

Other then that , looked after these electric APs will safely take you around the world in comfort at the touch of a button

Watching a modern rate gyro AP handling quartering seas is magic

[Baby tug]

I would suggest you look at what commercial boats use if you want something that is reliable , hydraulic , Solid state electronics , Jog levers, I love follow up jog levers ,Mount your reversible hydraulic pump right next to the steering cylinder with hydraulic hoses that are only about 12 inches to 16 inches long , you can put quick connectors on those hoses you’ll never have any trouble with your auto pilot , I have a com nav 1001 That’s probably 20 years old never one problem , the 2001 is for vessels to 500 feet or more

[RaymondR]

Originally Posted by goboatingnow

I agree re balance

I spent an interesting afternoon sitting in the repair area of my local raymarine dealer ( Pharos marine) the tech guy there is very capable and he showed me various failures on Ray marine linear drive abs jefa drives ( which I have ). He certainly convinced me of the repair-ability of the 2nd gen Ray marine drive

I think these days carefully maintained and a reasonable balanced boat an electric AP will happily cross oceans without incident and even then some are easily repaired.

( the jefa ones being more vulnerable then the raymarine)

It’s always great to spend an hour or two chatting and helping the repair hours as you find out what’s actually causing issues.

Hence for raymaribe arms a gearbox spares kit for jefa linear arms , you need a clutch ring and clutch pin as these are what failed it seems.

Other then that , looked after these electric APs will safely take you around the world in comfort at the touch of a button

Watching a modern rate gyro AP handling quartering seas is magic

I think you mean "mechanical drives" rather than "electric drives" since they all use electric motors controlled by the electronic processor. "Hydraulic drives" use an electric motor to drive a hydraulic pump and "mechanical drives" use one to drive mechanical reduction gears to drive either a screw mechanism or rack and pinion or spur gears on a quadrant.

[Baby tug]

Mechanical drives are a thing of the past , In my opinion and a lot other people’s opinions too

[RaymondR]

From a durability viewpoint one of the significant comparative aspects is the inherent shock absorbent capabilities the compressibility of the hydraulic fluid and expandability of the hoese and tubes in the system infers.

Because of the rigidity and forms of the materials and services used in mechanical systems the shock loadings imposed upon them tend to create very high stresses in their components.

Shock loadings in hydraulic systems are very easy to avoid or dissipate which is why the shock absorbers in your motor are hydraulic devices.

[Pete7]

Originally Posted by RaymondR

From a durability viewpoint one of the significant comparative aspects is the inherent shock absorbent capabilities the compressibility of the hydraulic fluid and expandability of the hoese and tubes in the system infers.

Because of the rigidity and forms of the materials and services used in mechanical systems the shock loadings imposed upon them tend to create very high stresses in their components.

Shock loadings in hydraulic systems are very easy to avoid or dissipate which is why the shock absorbers in your motor are hydraulic devices.

Are you sure? You might have some absorbent effect if you have bubbles in the lines, but I am doubtful hydraulic fluid compresses much at the pressures we are talking about. More likely fluid escapes passed the seals to the other side of the drive or helm under higher pressure, particularly after a few years. The helm unit is also a problem especially if its black since it heats up in strong sunlight and dumps red stuff all over the place. Boy is it slippery. At night it cools down and sucks air into the top of the helm.

A shock loading on my mechanical system which is via drag link, simply turns the wheel. Indeed, out of the water pressing on the rudder with a paint brush turns the rudder and wheel.

Pete

[MicHughV]

Auto pilots...even good one's...have a limit to how much they can do when the going gets rough, and I have found that hand steering, however tiring it may be, provides the best option in those cases...for the simply reason, that a person behind the wheel, can "see" the weather, thereby also "anticipate" the wave impact..during the day anyway...

I see autopilots as an "aid", but not the sole mechanism to steering a boat. Off course, if you are single-handing you'd likely take a contrary view.

[goboatingnow]

Originally Posted by MicHughV

Auto pilots...even good one's...have a limit to how much they can do when the going gets rough, and I have found that hand steering, however tiring it may be, provides the best option in those cases...for the simply reason, that a person behind the wheel, can "see" the weather, thereby also "anticipate" the wave impact..during the day anyway...

I see autopilots as an "aid", but not the sole mechanism to steering a boat. Off course, if you are single-handing you'd likely take a contrary view.

Modern rate gyros can effectively “ see” cause they sense boat movements in advance of thd helm. Eqyalk helms can’t See at night it takes very experienced helms to “ steer “ around weather.

My experience these days is that in all but very very extreme weather modern APs often steer better then human’s helms.

Of course no AP is perfect but then humans arbt either

To me they are indispensable on a cruising boat and I ve crossed two oceans without hand steering at all.

[MicHughV]

Well, you need someone on watch, regardless of AP or not, so time spent behind the wheel can serve two purposes.

Again, singlehanders do not have this luxury, so yes, I can an AP being a "must have" tool, but even AP's that can anticipate a wave, cannot anticipate a windshift.

I will grant you that the singlehanded around the world racers have some insane AP's on their boats, but I don't think these are readily available to the general public.

[goboatingnow]

Practice behind the wheel can be useful but in long passage tiredness causes errors. Many people can be competent but not “ wise “ helms

Hence my preference is always for a high quality AP fitment. It’s a life saver imho

I just dumped put my old wheel pilot and now have a new EV1 under deck linear arm fitment. Night and day downwind, I have neck wearing wifi autopilot control/dodge pendant unit also

Nothing like full lunch on the bow with “ Geogre “ doing the work. !!!

[Pete7]

Originally Posted by MicHughV

I will grant you that the singlehanded around the world racers have some insane AP's on their boats, but I don't think these are readily available to the general public.

Even many entry level pilots now have gyro compasses. I reviewed ours here in Post 12:

https://www.cruisersforum.com/forums...ew-136885.html

[goboatingnow]

Originally Posted by Pete7

Even many entry level pilots now have gyro compasses. I reviewed ours here in Post 12:



https://www.cruisersforum.com/forums...ew-136885.html

Yes very common now

[goboatingnow]

Originally Posted by PUDDLE JUMPER II

Bingo...

My experience with marine specific hydraulics Was parts had nothing was common with conventional plant or agricultural hydraulics. Seals were non standard as were hose fittings

[Baby tug]

I don’t know for sure but I think an iPad has a gyrocompass in it ,I’m waiting for them to come out with an app for an iPad that’ll work as a computer and compass for an auto pilot , and then you would need some off the shelf hydraulics and a Bluetooth 30 amp switch