Autopilot question

[blythespirit]

I hope this is the right forum and I can get some advice.

I just purchased a Raymarine M81202 hydraulic autopilot and ram drive system, based on what was recommended for a boat my size with hydraulic steering.

After receiving the package, I read the manual and it specifically says 'for mechanical steering.'

Raymarine tells me this is a stand alone system and works independent of the present steering. The hydraulic piston is mounted on the opposite side of the steering piston. For some reason that doesn't sound right. The steering piston can move the AP piston, but can the AP piston move the steering piston.

I know the AP has a clutch so when not powered up it's in idle so the steering cylinder can push against the AP cylinder.

If anyone has a similar set-up I'd like to know how it works.

Ian
S/V Blythe Spirit
Panama, Panama

[djmarchand]

You have hydraulic steering, right? Then you need a hydraulic pump as the actuator for your autopilot. It splices into the hydraulic lines and takes the place of the wheel steering hydraulic pump.

These hydraulic pumps come in a couple of sizes which needs to be matched to your steering's ram volume0 usually stamped on the side.

What you have sounds like a hydraulic ram actuator. That kind of actuator works for pure mechanical.- ie cable or chain, steering.

Go into the Raymarine web site, look for manuals and download the installation manual for hydraulic steering. It is all explained there.

David

[blythespirit]

Thanks for the reply, I've got the whole magugala, the entire "sail package" as they call it including the M81202 type three hydraulic linear drive. It comes with motor and sensor, etc. And the Evolution EV-1 ACU-400 package. After days on the Raymarine forum, this is what the tech suggested. There's no problem hooking the hydraulic drive onto the rudder post, I've a long extension which is like a small tiller already attached for my current AP system

In my current, old, burned out system, the steering hydraulic lines are "T'd" into the AP hydraulic pump which runs of a 12v chain and sprocket motor. (Did I tell you this is very old)

I have asked raymarine through their tech lines why can't I do that with this drive unit. His only answer was the unit wasn't designed for that. I was handed off to another tech, then another and they had the same answer.

The only thing I got from 4 hours of discussion was that I can mount the unit on the opposite side of the hull opposing the steering cylinder so it would work independently. That sounds fine in theory, but, the AP has a clutch in the hydraulics so the steering could push against the AP cylinder, but my concern is whether the AP cylinder can push against the steering cylinder. And was wondering among the thousands of members here does anyone have a set-up like that?

[Terra Nova]

If your boat has hydraulic steering, then you bought the wrong a/p. The a/p # you list shows "The hydraulic linear drive system is designed for boats with existing mechanical steering systems, not hydraulic steering systems".

You have the wrong autopilot.

[blythespirit]

Thanks, it's the one the Raymarine tech told me to buy, I don't know if I'm stuck with it or can I exchange it. I'm in Panama and freight will almost cost the same as a different unit.

thanks anyway for the help

[djmarchand]

Terra Nova said in more explicit terms what I was trying to say. But you may be able to salvage the system you bought.

The electronics on autopilots are all the same whether you have a hydraulic ram actuator (which is what you apparently bought), an electric linear or rotary actuator or a hydraulic pump (which is what you need).

But if your existing hydraulic pump is still functional, then hook up all of the Raymarine electrics except for the actuator. Hook up the new Raymarine Evolution EV-1 ACU-400 output (motor terminals A and B) to your existing hydraulic pump. The autopilot won't know it is another brand, xx years old and will work just fine.

Go to raymarine.com, select documents and manuals, then select Drive Units and look at the Hydraulic Pump Installation Guide pdf document. Your hydraulic motor should look very similar to Raymarine's.

If your old hydraulic pump is no good, then just buy a new one from Raymarine or anyone else for that matter. You probably can find a salvage one locally. Every thing else you bought should work fine.

Raymarine techs may know something about electronics, but apparently they know nothing about mechanics/hydraulics.

David