Autohelm on NC33

[Anonymous]

Evening all,

Having used our autohelm for the first time in anger last weekend I was wondering if you experienced hands could advise me. We were motor sailing between Plymouth and Dartmouth (UK) with a sea slightly abaft the beam. The autohelm was working far too hard. When steering manually there was no need to correct at all, often for minutes, but the autohelm was throwing the bow around like nobody’s business – didn’t half make it uncomfortable.

The kit is the original bit taken from a WWII tank – built isn’t the word!.

I am hoping that it all boils down to how the machine is set up – “Sensitivity”, “Rudder” and a 3rd dial that I can’t remember.

I would welcome any advice on a “good” setting for these various controls.

Thanks

Nick

[Anonymous]

what make /model ?  Does it drive a hydraulic pump or it is direct drive ?

[Anonymous]

Hi,

Its a Neco chain drive.

[Anonymous]

I “Googled” Neco but could not find a link to it – on Discovery III I installed a Raymarine computer linked to the hydraulic pump in the steering system.  I also have Raymarine chartplotter etc throughout.  I found that I had to adjust the sensitivity of the autohelm over and above the “auto learn” functionality it has.  Each season I always feels it is a wise to do a recalibration.

[Anonymous]

We are doing the long leg from Dartmouth to Wareham on Sunday with little wind so it will be an opportunity to try and find balanced settings. I found the manual on board so fingers crossed.

Thanks for your helpful comments.

Nick

[John Crump]

Not trying to insult your intelligence but I spent ages trying to solve a similar problem to find that she who dances backwards had put the dirty washing in the locker partially jamming the compass so that it wasn’t swinging freely. Hope yours is something as simple.

[Anonymous]

Monark – I uploaded a document last night from Alan that has contacts in it for Neco – look under technical ->suppliers

[Anonymous]

Thanks Discoveryiii. Will do. Rgds Nick

[Anonymous]

Siftasam, I must confess to not really knowing how a fluxgate compass works so I guess I had better have a look and make sure it is not stuck up even if not jammed with washing. Thanks for the practical advice.

Rgds Nick

[Anonymous]

My NC 33 Zarzuela has its original autohelm (intalled 40 years ago). Electric motor in locker below wheel, bicycle chain to ratchet behind the wheel, rods to rudder stock with wheel position indicator and a dedicated transmitting magnetic compass in the bow locker (needs special deviation table as close to anchor chain locker).

When close hauled  i set full sensitivity and max rudder angle. In a strong wind, and even with manual steering, Zarzuela will fly up into the wind on account of her too small rudder.

Down wind I set 10 degrees rudder and low sensitivity but again, in a strong wind, the small rudder fails to keep charge and a crash jibe can ensue so would be in manual steering.

In F3 or less I find my autohelm brilliant and, particularly if sailing single handed, enables me to get on with the other tasks safely.

[Anonymous]

Dear John,

Thanks, that’s really interesting personal experience. I am intrigued by your description of the extreme weather helm. So far I have been impressed how well balanced my boat is although I have only sailed with genoa and mizzen ie without main.You highlighted your small rudder. Is that something they modified between your boat and later boats? If Zarzuela is 40 years old I guess she is a boat from the early 70’s. Mine is an early 1978 – full aft deck and GRP pilothouse etc.is my rudder the same as yours (if that’s not too personal)?

Regards

Nick

[Anonymous]

By the way John, I assume from your comment about the compass deviation that no standardised adjustment is applied at installation to cope with the anchor chain it is adjusted using maths instead?

Rgds

Nick

[Anonymous]

Zarzuela is 1972 Hull No.224 bought by me 12 years ago. Your boat is a NC33 Mk1 I think. Different hull, keel, larger rudder (mine is mounted on a skeg) higher masts, external cockpit, larger sail area etc. yours has much better sailing qualities than mine.

I do not know whether Nauticats are supplied with a deviation table for their type. I “swung ship” to check the table I had.

Regards

John C

.

[Anonymous]

I was going to swing the boat for the standard compass but can’t see how you can do that for a compass that has no dial. Do you have to set the auto helm degrees to the true “heading” and see if it tries to adjust the wheel even though there is no forward motion and keep turning the helm dial until it stops trying to correct?

Regards

Nick

[Anonymous]

Nick

I have a magnetic ships head readout on the console and compare the autohelm dial heading with it to measure any deviation difference. Accurate enough to set a heading for, say, a Waypoint and then tweak it to CoG on the GPS.

Regards

John C.

 

 

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