OK to Mount Hydraulic Steering Rams on Deck?

[Chotu]

Originally Posted by Matt Johnson

Based on a previous photo you posted, it seemed like you could internally install the cylinder in the transom and have a linkage lead to the tiller. This could be done with a drag link or directly with one of the cylinders designed for transom hung rudders like:

https://www.vetus.com/en/vetus-hydra...g-rudders.html

Lecomble and Schimmt also make one that was used on Mini Transpac boats with great success.

I just looked at Wikipedia to see what a drag link is. Wow. Some major knowledge you have there.

If I were to mount it inside the boat under the stairs, I don’t see how the drag link would work in general and definitely don’t see how it would handle the kick up.

I think this picture of the old steering system is what you are talking about.

What I thought I’d do is make a ram mounting platform over one of those steps the tiller is on and attach it to the rudder cassette so the ram kicks up with the rest of the rudder cassette. Only issue is the tip of the rod sticking out the back of the ram will protrude through the hull and needs a hole. Jankey, I know. But not many options here.

PS: I already have the SeaStar rams mentioned up thread.

[Pete7]

Originally Posted by hurricanehole

Noticed the other day a manual sentence saying don’t install in a damp location.

I think there is a difference between constantly damp and exposed which gives the metal chance to dry out. Look at rigging that has that plastic stuff over it, soon attracts dirt and starts to corrode. Exposed to the elements keeps it clean and give it a chance to dry out.

Pete

[Pete7]

Originally Posted by hurricanehole

Noticed the other day a manual sentence saying don’t install in a damp location.

I think there is a difference between constantly damp and exposed which gives the metal chance to dry out. Look at rigging that has that plastic stuff over it, soon attracts dirt and starts to corrode. Exposed to the elements keeps it clean and give it a chance to dry out.

Pete

[Pete7]

Originally Posted by hurricanehole

Noticed the other day a manual sentence saying don’t install in a damp location.

I think there is a difference between constantly damp and exposed which gives the metal chance to dry out. Look at rigging that has that plastic stuff over it, soon attracts dirt and starts to corrode. Exposed to the elements keeps it clean and give it a chance to dry out.

If the drive is black and you are using it in a hot climate then the hydraulic oil can expand and leak past the seals since there are only low pressure systems. Used to keep a small bottle of oil and top up the wheel drive every so often with a tea spoon full. What you don't want is air in the system at all. In a hot climate I would make a sun cover in a light colour fabric to reflect the sun off both ram and wheel drive if also exposed.

Pete

[Tupaia]

Originally Posted by hurricanehole

Hi. New hydraulic system on my cat. Vetus. The ram sits on top of aft deck in front of aft crossbeam with a box over as cover. Anyway, here’s the head scratching uh oh part. Noticed the other day a manual sentence saying don’t install in a damp location.

Ahhh... Very Expensive Totally Useless, you can guess the last bit of acronym. They will deny all warranty claims for example : steering pump failure- Has it been near hydraulic fluid??? Waterlock failure - Has it been near hot water?? When your part fails and it will - Has it been near dampness or moisture?? I did get my pump replaced that I subsequently sold.

[Tupaia]

My rams live outside and kick up with the rudders.

They have a 3 sided plastic enclosure that protects them from spray and rain. Enclosing them completely will result in condensation and permanent state of dampness.

Any beads or droplets of water, spray or rain, that happen to bridge the gap between the ram rod and the cylinder will result in pitting of the ram rods, so even if you wash them with fresh water make sure there are no droplets left.

Changing out the standard ram rods with polished duplex stainless rods (most supplied rods are chromed) will eliminate these issues. Seals will wear slightly faster but they are pennies compared to new rods.

Selecting cylinders with outer wiper seals are also better.

Having them in a semi enclosure allows you to cover them in protective grease or Soft Seal spray and not get it all over guests.

[Dave_S]

I have kick up rudders and the same rams. They are concealed in a box which forms one of the sugar scoops steps. The lines, bypass valve and hardware would be a PITA for me if they were exposed on the steps.

[Tupaia]

Stops: Make sure you install substantial rudder stops. Your push pull setup would not be able to withstand the rudder being thrown hard over by wave action. This will apply to hydraulic rams as well you cannot relay on the ram itself to act as a stop.

[sinnerman]

Corrosion of the exposed sealing surfaces of the pistons would be my main concern

[Matt Johnson]

Rotating the tiller arm about 45 degrees should put the cylinder within the step. You'd then just have the shaft and tiller on the step connected with a ball joint.


We did something very similar on our last boat with a transon hung rudder and hydraulic autopilot ram. The hole in the transom where the shaft exited was covered with a sunbrella (because I had it lying around) boot like a cv boot. The cone shape of the boot allows the shaft to move in/out and side to side without the boot sliding. But a hard cover may be better to help with the tripping hazard.

Matt

[Chotu]

Originally Posted by Matt Johnson

Rotating the tiller arm about 45 degrees should put the cylinder within the step. You'd then just have the shaft and tiller on the step connected with a ball joint.


We did something very similar on our last boat with a transon hung rudder and hydraulic autopilot ram. The hole in the transom where the shaft exited was covered with a sunbrella (because I had it lying around) boot like a cv boot. The cone shape of the boot allows the shaft to move in/out and side to side without the boot sliding. But a hard cover may be better to help with the tripping hazard.

Matt

Great post!

This exactly what I had just decided to do talking with my “helper” (a knowledgeable guy). He had the same idea and we went with it.

I’ll get a new tiller arm sorted out at a machine shop and the ram will go fore and aft.

I have a simplified kickup release I came up with too where the ram base can just pop out of place.

[garyfdl]

Originally Posted by Chotu

Boots!!! A great idea!

Not necessarily. I've got 30 years of hydraulics experience, as a tech and a designer. Boots are fine in dirty environments (construction, mining, etc.) to protect the rod and keep dirt out of the system. But they can also trap moisture and cause corrosion. Boots are also limited by the length of the stroke, and don't work in applications with long rod 'throws'/travel.

Were it me? I'd forego boots and leave the rods exposed.

Also - if you can, set the rudder(s) so that the rod(s) is/are retracted i.e. in the cylinder(s) when not being used. That's the best way to protect them.

[Dave_S]

Have you considered designing in some Ackerman steering while your doing this?

[GRIT]

Originally Posted by Tupaia

Stops: Make sure you install substantial rudder stops. Your push pull setup would not be able to withstand the rudder being thrown hard over by wave action. This will apply to hydraulic rams as well you cannot relay on the ram itself to act as a stop.

Id like to understand this statement. Hydraulics don't allow the waves to move the rudders, so how they would be thrown hard over by a wave is puzzling.

I suspect a rudderstop couldnt hurt, but I don't see the necessity, if the system is functional.

I know on construction equipment, we didn't have stops, as the piston, on full extension, would press against the cylinder end, effectively stopping movement. On retraction the same thing happened on the other end of the cylinder.

Cheers.
Paul.

[GRIT]

Originally Posted by Dave_S

Have you considered designing in some Ackerman steering while your doing this?

I studied the whole Ackerman thing, and I don't think it can possibly make a difference, unless you're constantly making very sharp turns. Even then, a rudder through the Waves, and water, is hardly like a tire on pavement.

In a marina, where you're likely to be making those sharp turns, the props do most of the turning. Meaning using the throttles and shifters, to play the engines.

We didn't use the Ackerman equation on GRIT, and she performs exactly as I would hope. I feel that with the backs of the rudders pointed outboard at 5 degrees, they would tend to induce drag, when going straight. We seldom have to trim the rudders more than a couple of degrees while sailing straight ahead, which must be near 99% of the time.

Count me as an Ackerman skeptic, for use on cats.

Do you have an Ackerman angle on your boat? Do you feel it helps in some way?

I'm genuinely curious.

Cheers.
Paul.