Hydraulic Steering

Wheel, tiller and autopilots
Future
Posts: 66
Joined: Sat May 12, 2007 12:07 am

Hydraulic Steering

Post by Future » Thu Jun 18, 2009 4:23 am

Looking for advice:

My plans call for a tie rod to link the two rudders. The tie rod is built into the bottom of the rear beam and will not be accessible once the beam is complete. The designer has specified a very large pipe as a tie rod.

My dilemma:

If anything was to happen to the tie rod (really small chance) you would have to completely demolish the rear beam to make repairs (I don’t like this idea)

So I am now looking at Hydraulic steering with a fluid link.

To the people using hydraulics what brands are you using?

What are your expected costs?

Are there any pitfalls?

Any thoughts or ideas greatly appreciated.

:D

44c
Posts: 1147
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Hydraulic Steering

Post by 44c » Thu Jun 18, 2009 6:10 am

I'm using Italian made Ultraflex hydraulics from Sam Allen imports.



I tried to work with Hydrive, but they wanted to specify a system that would have been just a tad on the big side for the USS Nimitz!



Whenever I just tried to order the parts I wanted they would always ask what boat it was going on then say "Oh no, you need this and this..."



They were specifying gear that could exert 400-500kg/metres torque! WTF FOR? No way could my rudders stand that.



The system I got can exert 58 kg/m which is plenty. (Think of a tiller 1 metre long with 58 kg force on it. Then imagine the same tiller with the 400+kg hydrive reckoned I needed!)



I have twin helms, twin fluid linked cylinders, an autopilot installation kit, and it all ran to around $2500.

madaz
Posts: 527
Joined: Thu Apr 26, 2007 7:47 am
Location: Hobart, Tasmania

Hydraulic Steering

Post by madaz » Thu Jun 18, 2009 8:29 am

I am looking into steering again at the moment, I wouldnt be to keen on sealing anything away either Adam, although I think Jim had some good photos of his steering which was something similar to Mikes idea.



I am looking at either a Teleflex cable system or hydraulics. I have had a single cable teleflex working but that requires a connecting bar to link the other rudder and It would have a few benefits to not have that connecting bar. i see also Teleflex have dual cable helms, therefore I could connect a cable to each tiller head and if one got broke for any reason the other would still steer (providing it wasnt the helm that broke) However they apear to be considerably dearer and getting toward hydraulic costs any.



I have put hydraulics in the to hard basket due to linking the rudders, maybe I should give that another look as i only have one helm. Do you have any links, photos etc Alan?

Future
Posts: 66
Joined: Sat May 12, 2007 12:07 am

Hydraulic Steering

Post by Future » Thu Jun 18, 2009 3:17 pm

I have approached Hydrive and the system they came up with was approximately $8000nz including the autohelm pump and controller. Every other the supplier I have approached so far has stated that a tie bar is still required because their cylinders will slowly fall out of alignment.



I will now look into Ultraflex hydraulics :D their price seems great even with the Aus / Nz dollar echange rate.

Thanks
Last edited by Future on Sat Jun 19, 2010 3:39 am, edited 1 time in total.

44c
Posts: 1147
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Hydraulic Steering

Post by 44c » Thu Jun 18, 2009 5:31 pm

I just recently got back from sailing an hydraulically steered Oram 39C from Cape York to Gove. The boat had sailed from Brisbane, and the owner said he hadn't had to re-align the rudders once.



But even if they do get out of alignment, fixing it is easy. You have to have a bypass valve on at least one of the cylinders so you can get fluid into the hydraulic link in the first place. Opening this valve allows that rudder to "freewheel" so it can be lined up with the other rudder.



A method I've heard described is to get the boat motoring in a straight line, open this valve, make sure the boat is still going straight, then close the valve.



Tony, this is the link to the Sam Allen website: http://www.samallen.com.au/index.php



And here's a link to the ultraflex catalogue: http://www.samallen.com.au/Ultraflex.pdf



Ultraflex also have cable steering systems, so they might interest you too.



IMHO a big plus of hydraulic steering is that once you have it, fitting a high quality and powerful autopilot is very simple and comparitively cheap. (Sam Allen also supply autopilot fitting kits.)

madaz
Posts: 527
Joined: Thu Apr 26, 2007 7:47 am
Location: Hobart, Tasmania

Hydraulic Steering

Post by madaz » Thu Jun 18, 2009 7:09 pm

sent you a PM Alan.... :roll:

puremajek
Posts: 751
Joined: Thu May 04, 2006 7:36 pm
Location: Brisbane Australia
Contact:

Hydraulic Steering

Post by puremajek » Fri Jun 19, 2009 7:19 am

Future



Just a thought, move the tie-rod to the aft of the beam. I too had my tie-rod internal and changed my mind midway through the build for similar reasons. To move it aft I drilled two holes through the hull and slid it out - took 5 minutes. It now sits in a simple cover rear of the beam.



What is the max design weight of the yacht on the water? We had hydraulics on our previous boat and went non-hydraulics on this one, due to its light weight. We have never regretted this decision.
James
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http://www.diycatamaran.com
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mahnamahna
Posts: 579
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Hydraulic Steering

Post by mahnamahna » Fri Jun 19, 2009 7:56 am

Hi Guys, this is a topic I have been giving a lot of thought to recently. Nine Lives (waller 11 mt) is being fitted with Teleflex steering and has a tie rod (inside the rear beam). I am watching it with interest to see if I like it. Hopefully this boat is finally going to be launched later this year so I can see first hand what this steering system is like.



For those not reading my blog, I have fitted a tie rod to my boat. Schionnings are not fans of tie rods but I like a mechanical link between the rudders. The main reason I did it is because it enabled me to move my emergency tiller that I hope never has to be deployed, from over the rudder posts down one of the stern steps, to back into the cabin by having a mechanical link (a pivot and pin attached to the tie rod) behind the normal helm position in the cockpit. I could not imagine having to helm for a couple of days from down there in the elements with the dangers that go with that.



Tie rods are a no no on Schionnings because of the weight that a free hung tie rod represents, so I am trying a light weight 30mm aluminum tie rod with 3mm walls which on its own would bend but inside a tight fit poly pipe and glassed onto the catwalk wont bend and is more than half the weight of a 70mm s/s rod with 5mm walls that Nine Lives uses. My only concern is flex. If I get major flexing of the boat bending the tie rod pipe it might bind. And I wont really know if this will happen until I launch.



My solution is to have removable linkages to the rudders and still have hydraulics to each mini tiller or if the teleflex works well I could have that to each rudder and the tie rod would just move back and forth as a redundant mechanical link until needed. If one link to a rudder fails the tie rod takes over. If flexing is a problem the linkages to the tie rod are removed. If I go with teleflex then I will attach the autopilot to the tie rod.

madaz
Posts: 527
Joined: Thu Apr 26, 2007 7:47 am
Location: Hobart, Tasmania

Hydraulic Steering

Post by madaz » Fri Jun 19, 2009 8:15 am

How is Nine lives going Paul? I t would be good to see a few new pics on the link. !! :roll: when you can



I did have a tie rod system hooked up but I am not overly happy with it. i had 40mm alloy pipe with 5mm wall and wrapped it in carbon fibre tape. It wasnt supported along its length though as I think Jims and perhaps nine lives is? So when i did a few tests on it i wasnt happy with the flex i was getting more of a wobble which i think would get a bit harmonic and once started would keep going? not sure. thats why I am looking at either hydraulic or a dual teleflex cable (one cable for each rudder)

mahnamahna
Posts: 579
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Hydraulic Steering

Post by mahnamahna » Fri Jun 19, 2009 9:24 pm

madaz wrote:How is Nine lives going Paul? I t would be good to see a few new pics on the link. !! :roll: when you can

I did have a tie rod system hooked up but I am not overly happy with it. i had 40mm alloy pipe with 5mm wall and wrapped it in carbon fibre tape. It wasnt supported along its length though as I think Jims and perhaps nine lives is? So when i did a few tests on it i wasnt happy with the flex i was getting more of a wobble which i think would get a bit harmonic and once started would keep going? not sure. thats why I am looking at either hydraulic or a dual teleflex cable (one cable for each rudder)


Nine Lives tie rod is a heavy stainless pipe, 75mm diameter, 5mm walls that is not supported. It hangs inside a void between 2 bulkheads that form the rear beam. It will only be supported by the mini tiller attaching points at each end. That is why it is so heavy, so it cannot bend as it is unsupported.



Mine on the other hand is much much lighter. I would guess at least half the weight perhaps more, but it slides inside a poly pipe which has been glassed using uni and double bias to the duckboard. This combination wont bend unless the flexing of the boat across the beam is enough to make the rod bind inside the tube. I doubt this can happen because my rear beam is beefed up with box section that forms a raised duckboard under which are hatches that form a box girder. I cannot imagine there ever being enough force to flex this enough for the rod to bind. I did a test with the rod inside the pipe slung from 2 44 gallon drums so that it flexed and then moved the rod in the pipe and it was moving freely with quite a bow along the length so there would need to be a hell of a lot of flex in the boat before the rod would bind I think. With the rod also greased (probably with lanolin) inside the tube I think even with it flexed severely the tie rod will still move freely and the rudder system will work as planned. But I cannot be absolutely sure until I launch and test it. I dont think there are many if any Schionnings with tie rods.



So just to be absolutely safe I will be running direct hydaulic or teleflex links to each mini tiller. It would be much cheaper if I am going hydraulic to run a single ram to the tie rod but I fear that if I am wrong and the tie rod can bind I could end up with no steering so until I test it in action I really cant take that risk for the sake of a the small additional cost of running 2 hydraulic lines and rams (or a second teleflex cable) direct to the mini tillers.



There is still not much new to see on Nine Lives, but it is planned for the guys to paint it soon so once they do I will post the pics I have. Dennis (the owner) is in a wheel chair, and does not intend to live aboard for anything more than a few days at a time so the fit out is fairly basic.

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