Autopilot & Mechanical Steering Vol 2

[Gallivanters]

Over the past two months I've re-vamped our steering system by adding new cable & chain, steering quadrant, independent tiller arm (below the quadrant), NavMan 3380 Autopilot (great deal on Ebay) and high volume hydraulic pump to power a simple Wagner hydraulic ram. All items purchased seperately.

I believe I have everything in hand and I'm preparing to fiberglass in mounting points for the rudder position sensor and hydraulic ram.

But - I remain at a quandry about the hydraulic pump & ram.

The chandlery where I purchased the pump sells a package pump with ram AND solenoid clutch mechanism which allows for hand steering whenever the autopilot is on standby. Push a button and off we go! Simple. Automatic. Easy installation.

If I install the pump to ram which I now have in hand - there will be no automatic clutch and will require installing a pair of "tee" fittings and running a tubing circut with manual ball valve and remote power switch to the cockpit in order to switch between manual and auto steering.

My question is this: which method would provide me with a better steering system?

I like the simplicity of the first package option but like the reliability of the manual switch-over.

Do automatic solenoid clutches fail very often? Will adding 10 meters of additional tubing add significant friction to the steering system when hand steering?

Suggestions?

Happy Holidaze!

Kirk

[Trim50]

Kirk,

Tough questions! I haven't had any problems with my automatic clutch. It is a very simple mechanism and I can't see that it would be prone to failure.

As far as hydraulic friction, 10 meters seems like a lot...but it really depends more on tube material, fittings, turns and tube diameter. Figure on a couple psi pressure drop in every 90 degree.

Ken

[MMNETSEA]

Kirk,

Two questions around the same issue -

One : Is the solenoid electrically activated ?

Two : If it is , what happens when there is "no fire in the wire" ? Can you then go to manual ??

Richard

PS. If you install tubing , keep the ID diameter as large as possible.

[haffiman37]

The cheap purchase price of some items might soon be eaten off by add-ons and function problems.

If You have to pull hydralic lines all the way to the steering pedestall, buy a wheel-pump and go all hydraulic. For the distance You mention a minimum of 3/8 copper tubing is what I would recomend, no flexible/plastic lines.

If You still want to stay by the combined mechanical/hydraulic just buy an electric solenoid valve and install between the lines from the ram as close to the ram as possible. For safety reason use a valve that is 'open' when no power is applied. If power failes, You have the manual steering operational. When putting auto pilot 'on' the valve will close and everything is set to run.

[delatbabel]

You have a fallback to the tiller, correct?

In that case I would say that what has been suggested in terms of going all hydraulic should give you sufficient reliability, but I would be inclined to add a windvane system to run off the tiller. I have one of the aries ones connected up to my tiller (I have a wheel and a tiller on Chiara Stella), I'll get you some photos if you like but the reliability and utility of the windvane should really compensate for any issues with the hydraulics, computers, etc, in the Navman autopilot system.