Autopilots

Wheel, tiller and autopilots
mahnamahna
Posts: 579
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: Autopilots

Post by mahnamahna » Fri Feb 10, 2012 11:19 am

I was thinking of going the cheap way and getting a wheel steer raymarine. Am told they handle a 40ft cat ok in all but following seas and whilst they will still work, they work very hard.

Anyone else have one and what are your thoughts.

44c
Posts: 1147
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Re: Autopilots

Post by 44c » Fri Feb 10, 2012 3:17 pm

Yeah it's a big investment, but IMO it's worth paying for one that is going to do the job. Hand steering on passages gets pretty old pretty fast. I've had to do it a couple of times....

Downwind is where you really need the pilot to be able to keep on course.

I've done a fair bit of forum searching about autopilots while searching for a new one. There seems to be universal approval for the Simrad ones. And with exchange rates what they are, now is a great time to be buying.

And really, the difference between a cheap one and a good one isn't so much, in the overall scheme.

mahnamahna
Posts: 579
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: Autopilots

Post by mahnamahna » Fri Feb 10, 2012 6:26 pm

I assume the Simrad one you are talking about is hydraulic and a pump is placed in the line to take over from the helm pump, which I assume you have to be able to bypass when the autopilot pump takes over and its pump has to be bypassed when not in use and hand steering? Is my understanding correct? I would imagine that a hydraulic autopilot would draw much much less power than the electric gear driven wheel steer systems.

44c
Posts: 1147
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Re: Autopilots

Post by 44c » Sat Feb 11, 2012 8:26 am

The A/P pump is plumbed in parrallel with the helm pump(s). So you really don't have to do anything but switch the pilot on.

Some helm pumps don't have anti-feedback valves, if that was the case you'd need to have a shut off valve to isolate the helm pump.

If you have mechanical or cable steering, instead of a pump you'd fit a rotary drive, which drives the wheel by chain, or an electro mechanical ram, or a hydraulic pump and ram. The rotary drive and hydraulic pump/ram seem to have better reliability.

I doubt there would be much difference in the power consumption between them.

Trev
Posts: 160
Joined: Thu Jan 15, 2009 2:56 am
Location: Moruya NSW

Re: Autopilots

Post by Trev » Sat Feb 11, 2012 9:03 am

Hi Guys
I just installed a Simrad auto pilot pump, I haven't connected it electrically, but I just 'T" ed it into the hydraulic system, pretty straight forward, but like I said I haven't had it working yet because I only bought the pump because it was easy to install now, but the rest of the system works so it should be right ???
Trev

Image

Smooth Cruiser
Posts: 583
Joined: Thu May 11, 2006 1:51 am
Location: Brisbane

Re: Autopilots

Post by Smooth Cruiser » Tue Feb 14, 2012 12:36 am

I've got an NKE (French brand) hydraulic autopilot and find it very good - it is a hydraulic pump and ram similar to but with much faster movement than a Raymarine Tillerpilot (which is also fitted as an emergency spare). I think it is much more capable downwind at speed. Would recommend it but American units can probably be landed here cheaper.

puremajek
Posts: 751
Joined: Thu May 04, 2006 7:36 pm
Location: Brisbane Australia

Re: Autopilots

Post by puremajek » Tue Feb 14, 2012 9:56 pm

Am told they handle a 40ft cat ok in all but following seas and whilst they will still work, they work very hard.
Anyone else have one and what are your thoughts.
Hi Paul
Who ever gave you this information, is fairly accurate. We have a Raymarine wheel-pilot (with full box and dice) and love its simplicity and ease of use, BUT...
I would say that its best operating maximum weight would be (5000-6000kg), Raymarine say a bit more. On our latest video on Youtube (and the piece at the end - the Ch9 footage), she was working very hard. Did the job, but was approaching its peak (in my limited autopilot experience). We could have easily increased the sensitivity, but it would then have been working even harder.

Would we buy another, definitely. But only if under 5000kg (6000kg loaded). The new Raymarine X10 (I think its called) has supposedly had many more bugs ironed out??? Hope this helps, James
James
______________________________________________
http://www.diycatamaran.com
http://www.puremajek.com
______________________________________________

mahnamahna
Posts: 579
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: Autopilots

Post by mahnamahna » Wed Feb 15, 2012 9:02 am

Hi James, the guy that has one that gave me this info wants to fit a linear drive if he could afford it. It got me thinking about redundancy and having back ups if we ever get as far as long ocean passaging. If budget permits I will probably go for a hydraulic drive autopilot as others here are doing. But wonder if its not a good idea to build into the helm position the ability to fit a wheel steer unit as a back up to the hydraulic set up. You can get the Raymarine wheel steer now for about $1400 delivered, and as 44 pointed out, about $3000 including the hydraulic pump for say the Simrad system. With the wheel steer drive system fitted but dormant, if there was ever a problem with the hydraulically driven unit (I doubt the actual hydraulics would fail, more likely the electronic brain that pushes the hydraulic pump) you could just turn on the electronic head unit of the raymarine, engage the motor via the clutch lever and you are back on your way again.

The Raymarine X1 wheel pilot claims to be suitable for boats to 7500kgs (laden). My boat if I have stuck close to the guidelines should end up at 4500kgs dry, and recommended payload of 1500kgs giving a total of 6000kgs. Even if I blow out either the build or the load by say 500kgs, I will still be 1000kgs below its max rating or about 15% below. And I am sure they have to build in a safety factor so that someone that has a slightly overloaded 7500kgs boat at say 8000kgs the system will still cope albeit under load pushing the safety factor to about 20% below its actual capacity. Thats a fairly safe margin I would have thought.

Other than an extra $1400 is there anything else I am overlooking that make this idea not workable? Is it overkill? I read blogs of people who take a complete second unit of their chosen system with them as back up, so how would this be any different especially from a cost perspective, it would actually be cheaper, and if it works what are the thoughts on this idea?

Smooth Cruiser
Posts: 583
Joined: Thu May 11, 2006 1:51 am
Location: Brisbane

Re: Autopilots

Post by Smooth Cruiser » Wed Feb 15, 2012 4:02 pm

Redundancy is always a good idea - particularly if heading to remote areas. Sailing long distances without an autopilot on a short handed boat can be a major problem. I have the hydraulic unit and a standalone Raymarine unit as a complete spare with no common parts. At the end of the day it comes down to cost vs benefit for your circumstances. If, at the end of a long passage that you had hand steered all the way because your single autopilot failed, someone said you could have avoided that by spending $1400, would you consider it worthwhile? IMHO yes but it depends on your priorities and your usage expectations.

Jim
Posts: 691
Joined: Fri May 19, 2006 8:25 am
Location: Cairns

Re: Autopilots

Post by Jim » Wed Feb 15, 2012 5:11 pm

If I never have to touch the helm on a trip on my boat I am a happy camper, I usually have the auto helm set before I go through the last channel markers. Only once have I had to turn the auto pilot off and that was in a big and short following sea when it just couldn't cope. Any cat I have ever been on, both power and sail are absolute pigs in a big following sea, they will not go in a straight line without huge amounts of input on the steering. They will turn up to 60 degrees on the top of a wave and shoot off on that direction, say to port, then when the starboard bow ploughs into the trough of the wave it rips around to starboard. For any autohelm to keep up with that sort of sea is a very big ask, and trying to keep wind in the sails is an even bigger ask. It is easier on those occasions to turn it off, save your batteries (and your mind) and steer by hand which will with quite a lot of effort make the boat track fairly straight. Perfect conditions for a parachute sail. But that is another subject.
Jim.

Post Reply