Hydraulic Steering question

[smokediver]

I am going to be adding a helm back setup on my boat this year and before I do would like know if anyone has a good reason to add twin rams vs single. It's about a grand difference give or take. I am leaning towards going with a single ram. My thought process is if one ram fails so does the other one as it is a looped system. There can't be excess strain on one side of the steering pin unless there is play in the ram itself. I would imagine there is more force being applied to one side of the transom but is it a factor really ? Thanks in advance.

[gcarter]

The single ram is more than sufficient. After all every Arneson has a single cylinder.
However, I'd add a two cylinder system so the steering is equal in both directions.
Single cylinder has unbalanced force and speed due to the difference in areas on
both sides of the piston.

[smokediver]

Thanks for the info George. That makes sense.

[gcarter]

John, if you want to save some money, you can piece one together like I did.
The cost would probably be at least $1000 less than the cheapest kit.
It may take a little longer to get all your pieces together, but the rewards
(doing it yourself, and saving money) are wonderful.
My TR thread has all the details.

[smokediver]

Yeah , I saw what you did George as I followed your build pretty close ! I think I am leaning towards doing a single ram helm back setup and if i don't like the handling i can always add the second ram as long as I order the right helm

[gcarter]

The helm can always be modified. The difference is just a few parts and different length bolts.

[Conquistador_del_mar]

The single ram is more than sufficient. After all every Arneson has a single cylinder.
However, I'd add a two cylinder system so the steering is equal in both directions.
Single cylinder has unbalanced force and speed due to the difference in areas on
both sides of the piston.

George, I have been trying to understand why there would be a difference in speed of the ram if it is mounted in the correct location for full travel. I never noticed this on my 23' Warlock with a single ram IMCO add on system, but I might just not have noticed any discernible speed difference from one side to the other. Maybe you could elaborate?

[gcarter]

Bill, there may not be a really discernible difference. But in theory there is. If the helm is
turned at the same rate of rotation from left to right, one way will produce more movement of
the piston rod than the other direction.
The output of the helm is constant, i.e., one revolution of the helm will move (or displace)
a set amount of fluid (mine is about 13 cu. in), but the cylinder has a different displacement
on each side of the cylinder's piston due to area of the piston rod on one side of the piston.
So if one revolution of helm fluid is forced into the smaller side (rod side) of the piston, it
would have to move faster to accept the fluid, than the other end of the cylinder w/its
larger displacement.

[Ralph Savarese]

Go back and look at my old posts. Search external hydraulic steering. You will see my posts with pictures. Single handed the best thing I ever did to the boat in 50 years!