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Privilege · 06-02-2017, 17:49

An experienced sailor was on my boat the other day and commented that I needed too many turns on my wheel for a full swing. It takes 6.5 turns.

I have a catamaran with two rudders turned by a hydraulic system. It turns very easily with no air leaks or problems. I have a 10.2 cu arm with a 7" stroke. The helm pump is a Seastar HH5271 with a 1.7cu.in capacity. To reduce the amount of turns, is it simply a matter of increasing the size of the helm pump to, say the 2.4cu version? Will my autopilot like it more? Presumably it means less work for it?

I'd appreciate any thoughts.

Dave_S · 06-02-2017, 19:42

I don't know the gear you have but on my 7 piston hydraulic pump (directly attached to the wheel) there is an adjustment. It varies the amount of available travel of each piston to allow it to pump more or less fluid. The difference is about 6 turns, or all the way in, 4 turns lock to lock. The adjuster on mine is obvious yours may be concealed if you have one. *Not all pumps are piston/cam type.

HankOnthewater · 06-02-2017, 19:54

By the looks of it you supplied the answers already. As a disclaimer: I do not know the model of your pump.

There are also the following points to consider:
- if you were to double the pump capacity, without changing anything else lock to lock would be then 6.5:2=3.25 turns
- with a pump twice the size, the manual steering will be twice as heavy
- if you have an electrical pump (to pump oil) for the autopilot you use on the same ram, that should not make any difference
- if you use an electric motor to drive the helm and 'manual' pump for the autopilot ie via chain/sprocket/belt, you may need to invest in a larger motor, as the effort is twice as big if you double the pump capacity, without changing the gearing
- if the manual steering is too heavy with a bigger pump, then the wheel can be enlarged, or the gearing reduced, if the steering wheel and pump are not on the same shaft
- at the same token, if the pump is not on the same shaft as the steering wheel, you may be able to change the gearing to a more direct one, ie without changing the pump.

Terra Nova · 07-02-2017, 10:59

Quote:

Originally Posted by Privilege

An experienced sailor was on my boat the other day and commented that I needed too many turns on my wheel for a full swing. It takes 6.5 turns...

Your friend is correct.

**boatman61** · 07-02-2017, 11:04

I have a screw on my pump which if you turn either increases or reduces the amount of turns from lock to lock.

Davidhoy · 07-02-2017, 13:01

I have a similar issue with my boat, and the helm pump is not adjustable, to my knowledge. Is changing out the helm pump the only realistic solution? Fortunately my autopilots are both electric hydraulic pumps, so it should not matter if I change out the helm pump.

Regards,
David.

Dave_S · 07-02-2017, 19:59

If you have no adjustment.

You can either change over the pump for a higher volume pump or change over the rams for ones which have a longer stroke for a given volume of fluid.

I think even with a cat (two rams) I think the rams will be cheaper than one pump. Not sure but I'd check pricing before making a decision.

Schooner Chandlery · 07-02-2017, 22:27

In that experienced sailors opinion, it was too many turns. If it's adjustable (as others have noted) you can work with it. If not, really it's up to you -- is this a problem or not? Are you happy with how your boat steering performs? Has the autopilot had problems in big quartering seas or other challenging conditions? Does it need to move the rudders more quickly? If neither your nor your autopilot have noted anything amiss or had problems, just chalk up the "experienced sailor's" statement of opinion as simply that: an opinion.

I would personally probably prefer less turns lock-to-lock. But if my autopilot was happy as is, I'd be fine with it. My monohull boat has the same 6.5 as your boat does. In my case it is because of the mechanical worm gear (not hydraulic) it is not adjustable. Because I was so sure it would BECOME a problem, while we were in the yard rebuilding our boat (this was before we ever sailed it) I had the rudder-to-worm-gear-flange machined to accept a turntable bearing and fully expected to disconnect the worm gear but leave it in place as a backup (just dropping in the 4 bolts to connect the gear flange to the rudder flange again) and install hydraulics to the rudder and a gear driven manual pump on the wheel. As a mechanical engineer, I had it all "figured out" and was set to do my modifications to convert to hydraulic as soon as the boat behaved in a way to confirm my suspicion that 6.5 was too many turns. As part of converting to hydraulic I'd planned on reducing that 6.5 to something more reasonable for me and my opinions.

Ah, but as it turns out, the 6.5 is perfectly fine for both me, my husband, and the autopilot in all conditions. Therefore, though the turntable bearing is in place, no hydraulic steering system was installed and I'm a happy camper...erg...happy sailor.

**Jim Cate** · 07-02-2017, 22:37

FWIW, I can not conceive of steering with 6.5 turns l/l! I'd find that just awful. Our cable driven steering is around 1.5 lock to lock, and to me, that's about right. I suppose that one becomes used to such slow response... maybe one fits what we used to call "necker's knobs" when I was a randy teenager!

For sure, if it were my boat I'd be searching for a means to speed up the steering!

Jim

Terra Nova · 08-02-2017, 06:07

Quote:

Originally Posted by Schooner Chandlery

...Has the autopilot had problems in big quartering seas or other challenging conditions? Does it need to move the rudders more quickly?...if my autopilot was happy as is, I'd be fine with it. ...

His hydraulic auto pilot has nothing to do with the wheel steering's 6.5 turns as it is independent.

**a64pilot** · 08-02-2017, 06:25

As a kid I used to drive fork lifts, we always had a knob on the steering wheel so that you could rapidly spin it. I assume this is what Jim is calling a "neckers knob"
They really worked well, you could spin a steering wheel much faster with that knob.
I'd at least give it a try, but if what you have works fine for you, who cares about what others think?

Here is one made for boats, out of 316 SS, for $12.
https://www.amazon.com/Amarine-made-.../dp/B00ESTTZUK

rwidman · 08-02-2017, 06:48

Quote:

Originally Posted by Schooner Chandlery

In that experienced sailors opinion, it was too many turns. If it's adjustable (as others have noted) you can work with it. If not, really it's up to you -- is this a problem or not? Are you happy with how your boat steering performs? Has the autopilot had problems in big quartering seas or other challenging conditions? Does it need to move the rudders more quickly? If neither your nor your autopilot have noted anything amiss or had problems, just chalk up the "experienced sailor's" statement of opinion as simply that: an opinion.
..........

Exactly!

If it doesn't bother you, you don't have a problem.

If you think you should change things, contact the manufacturer of your helm pump and cylinder(s). Ask them how to change things to meet your friend's expectations. Of course, your friend is questioning the judgment of your boat's manufacturer.

There's a possibility that you have air in the lines. Has it always been like this since it was new?

undercutter · 08-02-2017, 06:53

Quote:

Originally Posted by Terra Nova

Your friend is correct.

I do not think so.

Our boat is 6 turns and is just fine.

As others have said if your increase the size of the pump then the helm will be much more heavy or stiff. You could also reduce the size of your cylinders however this I would not recommend.

Sounds like you were happy before the seasoned sailor visited. Money for nothing in my opinion. How often do you have the helm hard over anyway, especially on a catamaran? I am sure that some of the posters on here have single cylinder steering or as has been said cable steering which is completely different.