tiller autopilot - weighing options

[CarinaPDX]

Originally Posted by Jim Cate

Could you post a link to such a drive, please? I'd be interested.

No problem. https://www.servocity.com/html/560_l...r_actuato.html I would probably use the 8" stroke version. In addition to being a lot more powerful, it has a position reference potentiometer, limit switches, overload clutch, and metal gears. All for $400. It would be a small project for a machine shop to fabricate adapters for the stock RM mounts, and with a cover glued together of wet suit material it should work well.

And as to the inadequacy of the control head to provide adequate current for such a drive, a pair of simple 12 volt relays would solve that problem.

Possibly not - the current SPX5 does not simply turn on and off the output (which older versions did, and would work with relays). Apparently an "H" drive circuit is needed to get an on/off output. I have not personally put a scope on it, but Brian at the above Pelagic link has; we discussed this a few years ago. It would not be a huge problem to solve, and certainly worth it for access to a better linear drive.

Greg

[Jim Cate]

Originally Posted by CarinaPDX

No problem. https://www.servocity.com/html/560_l...r_actuato.html I would probably use the 8" stroke version. In addition to being a lot more powerful, it has a position reference potentiometer, limit switches, overload clutch, and metal gears. All for $400. It would be a small project for a machine shop to fabricate adapters for the stock RM mounts, and with a cover glued together of wet suit material it should work well.

Possibly not - the current SPX5 does not simply turn on and off the output (which older versions did, and would work with relays). Apparently an "H" drive circuit is needed to get an on/off output. I have not personally put a scope on it, but Brian at the above Pelagic link has; we discussed this a few years ago. It would not be a huge problem to solve, and certainly worth it for access to a better linear drive.

Greg

Greg, thanks for that link. Looks very interesting, and makes one wonder how Autohelm/RM can justify their prices for entirely inadequate gear.

If I went that way, it would be as a substitute drive for the ST-4000 tiller pilot that was on our boat as a back up. It would drive the boat under modest conditions, as our boat has a pretty light helm. But the crappy little ball nut that supplies the drive to the extension rod soon fails, and RM will not sell that part separately. That old ST4000 controller is a simple off/left/right output AFAIK, and a couple of relays would take care of the current.

I do wonder about the duty cycle limit of 25% they quote for this unit... is that at max load or at any load? On our boat there are times when the a/p is steering more than 25% of the time, so this is a potential problem. I also would like to see current draw vs load info. 3 A at no load isn't too bad, just wonder how fast it goes up?

Anyhow, thanks for drawing my attention to these actuators. I haven't done any research along those lines, and with the very slow internet that I have access to here in New Caledonia, research ain't fun!

Cheers,

Jim

[laika]

Thanks for all the feedback!

Pelagic APs looks like a great company. I've reached out to Brian and have what looks like my answer in a combination of their gyro tiller pilot and windvane pilot. I can install the tiller pilot and by carrying a smaller actuator for the drive can simply swap out and use the same control head and drive electronics to double as a windvane pilot. Together with spare drive parts and remote for around $1000US.

They have readymade install kits for the monitor and aries vanes. Sounds like more coming in the future. I have a norvane so plan on cobbling something together based off their aries kit.

Brian mentioned my boat weight wasn't a problem for the tiller autopilot. A couple W32s are using the tiller APs w/o issue. Also not looking to rely on this primarily as a big weather AP, though redundancy to the vane is welcome.

Simple, smart, robust, non-proprietary, reasonably priced. I'm down!

[CarinaPDX]

Originally Posted by Jim Cate

Looks very interesting, and makes one wonder how Autohelm/RM can justify their prices for entirely inadequate gear.

They put the word "marine" on it. Simple.

But the crappy little ball nut that supplies the drive to the extension rod soon fails, and RM will not sell that part separately.

I'm not sure to what you are referring. If you are using an extension for the drive rod then you might be able to use the 12" servo drive I referenced.

That old ST4000 controller is a simple off/left/right output AFAIK, and a couple of relays would take care of the current.

It is simply two wires, with the polarity changing to change direction. I think you are right about it being off between driving but worth checking.

I do wonder about the duty cycle limit of 25% they quote for this unit... is that at max load or at any load? On our boat there are times when the a/p is steering more than 25% of the time, so this is a potential problem. I also would like to see current draw vs load info. 3 A at no load isn't too bad, just wonder how fast it goes up?

It should be adequate, but if you're worried it would be easy enough to add a thermal cutoff to the motor. At that price you could burn up three of them and still not pay for a single RM servo drive. [Edit: And with the much higher power rating I doubt you would overburden it for long enough to do damage.]

Greg

[charliehows]

like the look of that pelagic windpilot unit. Anyone using it?

[Vipe6]

Take a look at a Bcalmxp autopilot as well. It's just the course computer with sensors and no drive but the computer of the Bcalmxp takes almost any drive, hydraulic or mechanic. B-CALMXP intelligent Sailpilot
This autopilot has bluetooth and there"s an Adroid app to connect your smartphone to the pilot so you can use the phone as a remote control. Furthermore when the bluetooth connection is lost, the pilot considers this as a MOB situation (after ten seconds of audio alarm) and steers the boat in circles. When the boat is on engine it even cuts off the engine.

[Scaramanga F25]

More than the weight of the vessel, if you have a balanced rudder or a light helm in all conditions you may not require a heavy duty model.
The distance from the pilot attachment point on the tiller to the rudder axis is of some importance.

[ramblinrod]

In all cases, an auto pilot is something I feel no boat should be without, except the odd fair weather daysailer.


A tiller pilot is a great temporary" and "occasional use" autopilot. They are simply not suitable for continuous, long term use. First of all, they are not designed for heavy, continuous use, especially off-shore. Second, they have to be connected/disconnected/stowed all the time, to free the tiller from the cockpit, and so they don't grow legs. 500 hours for a tiller pilot is a lot of use. (To put in perspective, if you use auto 10% of the time, it may last as long as the engine before major servicing in likely required.)


For a small boat that occasionally needs Otto to hold to wind to raise sails, especially for ocassional single handing, a tiller pilot is perfect.


For a medium sized sailboat, the Raymarine EVO Wheel Pilot is awesome. Many wheel pilots have operated for many 1000's of nautical miles without fault. The new EVO system is easy to install and requires no sea trial calibration. It's plug and play with Raymarine current equipment, and easily integrated with older / other equipment.


For larger boats, and more extensive use (running time, frequency, and sea conditions) an EVO system with permanently linear or hydraulic drive is just the ticket.


Ramblin' Rod
Certified Raymarine Installer / Service Provider
www.sheenmarine.com

[brianb00]

Originally Posted by CarinaPDX

They put the word "marine" on it. Simple.


It is simply two wires, with the polarity changing to change direction. I think you are right about it being off between driving but worth checking.

It should be adequate, but if you're worried it would be easy enough to add a thermal cutoff to the motor. At that price you could burn up three of them and still not pay for a single RM servo drive. [Edit: And with the much higher power rating I doubt you would overburden it for long enough to do damage.]

Greg

Hi, The modern units drive the motor with a PWM signal, pulse width modulation. It is a digital way of creating something of an analog signal. A simple relay will not respond properly and if it did the relay noise would drive you crazy. You can hear the AP PWM signal in an AM or SSB radio by tuning around the dial. It will sound like a moderate pitched musical note. Older units were simple switching and in that case relays would be feasible . Relays fail due to contact wear, so carry some spares.

[CarinaPDX]

Originally Posted by ramblinrod

A tiller pilot is a great temporary" and "occasional use" autopilot. They are simply not suitable for continuous, long term use. First of all, they are not designed for heavy, continuous use, especially off-shore.

Apparently that is an accurate reflection of RayMarine's view of tillerpilots, and their tiller products are limited as a result. For those of us needing tiller pilots for heavy use the RM products are simply not up to the job in my experience, and clearly the experience of many other cruisers as well. Hence the interest in better tiller pilots and linear drive units. The need (market) is there, and if RM doesn't wish to supply products for it that is their choice, but it doesn't make the demand go away - nor does it make that demand illegitimate in any way. As other options appear we will be spending our money with them, and not RM.

Greg

[brownoarsman]

Thanks for showing another option for autopilots. My four month old ST2000 blew up 40 miles out of Charleston, SC. It would lock out in each direction and then crash gybe the boat. Tons of fun.
Luckily, I was able to heave to and reinstall my navico tp1800. Still works a treat even if it's older than I am.
RM believes the brains are fried and should cover it under warranty, but only time will tell ...


Sent from my iPhone using Cruisers Sailing Forum

[Pete7]

Originally Posted by ozskipper

I have also been struggling to justify the cost of the ev 100 system. At one stage I even considered (for my wheel steered boat) using the emergency tiller as an option and adding a tillerpilot instead. Mainly as my need for an autopilot is limited to a few coastal trips. Sadly, in my case, there is too much friction in the system for a tillerpilot to work efficiently.

We have this set up. Our Moody came with a tiller but I added a wheel. However, what to do with the ST2000+ on board? Only one thing for it try and see if it would drive both rudder and the wheel as well and it does very well. The tiller lifts up out of the way when not needed.

Ideally, we should upgrade to the Evo100 system, but its £1100 in the UK.

Pete

[Scaramanga F25]

Quite some time ago I had the opportunity to work on a vessel for the Round Alone Race, starting in Newport.
As I visited many other 50 and 60 footers with tillers I did ask how many tiller pilots they had in addition to their windvane.

About half a dozen would be the average answer.

[Rustic Charm]

Originally Posted by CarinaPDX

Leave a message for Brian via the web site and I am sure he will get back to you. I am certain it is powerful enough to power a strong drive, and if he doesn't offer a strong enough drive there are other sources for that part.

Greg

umm, it's now November and still havn't received a reply to my query.

[Scaramanga F25]

If your weather helm is still light in heavier air, go simple.
Both mentioned above have similar power but the 2000 is faster in correcting.
Your vane should take care of the helm in stronger winds.
I found that I used my autopilot under power or motorsailng the Monitor most of the time.