[casper]

just completed a 50' ketch, i installed a seastar helm pump but cannot get less then 14 turns lock to lock, i dont have space to use a bigger steering wheel, any advice ?

[Billy1119]

I can't say I'm an expert on hydraulic steering by any means, but I can say a bigger steering wheel wouldn't solve your problem even if you did have space. So, I assume the size of the pump and hydraulic ram at the other end are what determine how many rotations you'll get lock to lock. Saying that, are you confident you have all of the air worked out of the system? If you don't, that could account for the high number or rotations. Does this particular system have a pressurized accumulation tank for the fluid? Would it be a correct assumption that you only have one helm position? Maybe a little more information would be useful for us to help you determine a solution, including what you've tried up to this point.

[Billy1119]

Also, the size of the lines run from the pump to the rudder could play a role in the number of rotations. The larger the inside diameter, the more rotations it would take.

[casper]

Hi Billy,
I dont have a pressurized accumulator tank, the helm pump is the type with a small built in fluid tank,(not pressurized) i used 1/2' s/steel piping running from below the helm (center of boat) to the rudder pistons using standard high pressure rubber hoses to attach the helm pump and pistons to the piping, a "professional" installed the pump checked and bled the system and ended up putting thinner fluid in the system which reduced the turns from 18 to 14 cost a lot of money and said thats the best i'll get, i dont agree , do u think the pressurized fluid tank is the way to go

[wdrzal]

Can you post a few pictures of your equiptment, A pic is worth a thousand words.

Was this test and improvement under load ? Do you know the GPM of the pump and pressure its producing? cylinder Diameter?

[Billy1119]

Originally Posted by casper

Hi Billy,
I dont have a pressurized accumulator tank, the helm pump is the type with a small built in fluid tank,(not pressurized) i used 1/2' s/steel piping running from below the helm (center of boat) to the rudder pistons using standard high pressure rubber hoses to attach the helm pump and pistons to the piping, a "professional" installed the pump checked and bled the system and ended up putting thinner fluid in the system which reduced the turns from 18 to 14 cost a lot of money and said thats the best i'll get, i dont agree , do u think the pressurized fluid tank is the way to go

1/2 inch seems a little large - from what I see on SeaStar's site, most of their systems call for 3/8. The model number of the system would be useful, then we could look at it online and further help diagnose the problem.

http://ww2.seastarsteering.com/INBOARD/inboard.htm

I don't think a pressurized tank would help in your application, but someone correct me if I'm wrong. Even if it would be beneficial, I don't see how it could assist in reducing the number of turns.

Of the helm pumps on the website, the highest number I see is 6 turns lock to lock, so I suspect there is something pretty substantial creating your excessive number.

Again, 1/2 inch seems a little large, but does anyone out there think that would make this large of a difference? The size of the cylinder would also be useful, or if it's also a SeaStar unit, its model number would be great (assuming you have it laying around and don't have to crawl in the bilges to get it)

We'll get it going eventually (hopefully)

[casper]

Hi, I,ll only be back at the boat next weekend, I,ll be able to take the photo,s and get all the info required,The "professional" had tested it in the water but told me that because the whole system was new it would still be very stiff and would work any trapped air out after a while and improve, I have since travelled 300 miles with her to the port of east london (sa) where i have a berth, the system has loosened up quite nicely but no improvement on the turns lock to lock, I'll get back to u as soon as i have the other info in about a week
Casper

[Billy1119]

Sounds good. Let us know.

Seems to me, with a single station, any air left in the system would not likely escape on its own, even if there is a small tank at the pump. The air would have to make its way all the way to the helm to get replaced with fluid. With a single station, the fluid's only going to move so much within a range (unless there are no places in the line for air to be trapped, then the air could make its way up). Apparently, though, there's not air at the pump itself, because you would be able to feel it, and the pump would have to prime itself to actually start moving fluid (assuming it's setup like the systems I've messed with). I suppose before I make that assumption about no air at the pump, can you feel any difference when turning the wheel, or does it feel like it is constantly moving fluid and turning the rudder? Hopefully I'm making sense.

[wdrzal]

oh ok a manual hydraulic system. first fluid viscosity can affect the speed and ease a cylinder moves but not the ratio. the line size is irrelavant as to ratio, as long as there is no air in the lines, if a ounce of fluid is entered in on end a ounce will exit the other no matter the size of the line.

what will affect the ratio is pump output as compared to cylinder volume.

And air in the system, which I suspect since a lighter oil shouldn't affect the ratio since fluid is not compressable at any viscosity. Did you check to make sure the resevior is topped off.Depending of the configuration air doesn't always "work out" read instruction for bleeding requirments.Was this a new matched system? or was the pump seperate from the cylinders?

[Billy1119]

Originally Posted by wdrzal

the line size is irrelavant as to ratio, as long as there is no air in the lines, if a ounce of fluid is entered in on end a ounce will exit the other no matter the size of the line.

This makes sense to me, thanks for correcting me on that.

[casper]

Hi, the cylinders were bought seperate to the pump but i was led to belive that they were compatible, sounds like the problem and i'll check it out, i'll also bleed it again and get back to u next week

[casper]

Hi all,
Sorry that i took so long to reply but i'v been away, the cause of the problem was that the rams were incompatible with the helm pump , the rams were replaced and the problem solved.Billy i was wrong about the pipe size they were infact 3/8
Thanks to all for the advice

[Billy1119]

Glad you were able to sort out the issue and get things goin' again, Casper!