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Instruments and Autopilots - current systems


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Wind vane for passages, with a tiller pilot connection for when motoring or no winds. There is almost no load on the tiller pilot used in this way and you can use one of the lower powered versions  for that very reason.. plus a lot cheaper than a heavy duty ont directly connected to the tiller. The only proviso is to have the TP unit either out of the weather  as you can if connected to a capehorn self steering system or with a custom cover to prevent water getting where it shouldn't when connected to an aries etc.

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I'd have a tiller pilot over anything hydraulic any and every day all day long.

Its got to be at least 150 kilos lighter than what your suggesting.

A full Simrad system weighs about 20kg incl ram and pump.

Cant see how your tiller pilot weighs -130kg. And tiller pilots do not deal with difficult conditions very well in my experience. 

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Power generation is there anyway - towed gen weighs several KG, alternator weight several KG, solar panels weigh next to nothing, batteries would be there still AP or not - going from wind vane to AP we did not have to upgrade anything at all in the generation or storage systems. The towed gen is very useful in that if the AP is working harder it tends to be working harder...

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I'm in the camp of the electric tiller pilot sceptics.

I had three of two different brands over 3 years with a previous boat. Yes, that is a few years ago now. All three did not last a year of regular Cook Strait crossings. Maybe they have improved, but I've yet to see the evidence.

These are normally worm drive systems, often with many plastic components, even the tiller connection. I've seen quite a few of those connections fail over the years. I do know of one cruiser with a 30ftr that uses one, and has had a ss end made for it for the tiller connection. Mostly, the manufacturers don't say they are suitable for crossing oceans!

Personally I think on a small boat without room for solar and or wind gen, a wind vane remains the best option.

For weight, 150kg is way too much - if you just want an AP power unit. The best way is to generate as required - wind gen and solar works best. If weight conscious, then the new lithium based fast charge batts make a lot of sense, as does a large frame hot rated high output alternator. Some lithium bats can be charged at their rated capacity, and fully discharged iirc. That means a 200amp hour batt can be fully charged with a 200 amp alt in an hours engine running. That would give about a day running an AP at an average 8 amps - a pretty high average. Lots of options to think about, so as an individual can select the system that best suits their particular requirements.

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KM, I don't agree with all of that. The Mini 650's are pretty similar to what you are trying to do. A reliable self steering system with minimum drag and min weight... They often use a hydraulic system. Here is a pic of one;

61300d1316016685-homemade-autopilot-mini

 

Similar to the unit pictured, the Navico HLD350 mk2 split version drive weighs approx. 9KG. The Compass, AP computer and rudder sensor are less than 3KG. Power requirement is 3.5-10amps depending on load. Average draw is towards the lower end. a 200 amp hour lithium bat  is in the region of 32 KG - but pricey! Really fast charge rates, heaps of cycles, 70% lighter than the equivalent wet cell battery.

 

The main issue as I see it for a small, light race boat is recharging. KM, be careful of those little gensets - often have say 2kw output IN 230V ONLY and a small trickle charge in 12-15v for batt charging - sometimes only 8amps odd. So to make them work, you have to have them, AND a mains battery charger to get decent DC output, with additional weight and losses in conversion.

 

Still the largest output for the least weight, IMO, is a good alternator - IF you have an engine (small diesel?) to drive it. If not, say you have an outboard only, then it is a real issue. A fuel cell maybe? How do the mini's manage this?

 

Oh, and also, as far as I can see, the mini 650's often use NKE as most mini's are French, and so is NKE. I cannot see a functional reason that they are better than any others - in fact they are not as clever as the top end B&G models.

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" in fact they are not as clever as the top end B&G models"

 

NKE developed very clever systems for the big solo trimarans that "know" enough to, for example, bear away when overpowered off the wind, and also release sheets when required, but not when not needed to, clever stuff indeed. So the solo sailor never needs to steer.

 

tb

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Yep, I agree with that TB, the B&G stuff was developed with monos in mind - using and for the Vendee globe boats - same thing, the APs steer virtually all the time. They have gust response and crash recovery etc built in - not something you need (or want!!) in a multi!  

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How much juice you need? Fuel cell will do 80-110w/hr in a 9kg footprint, 4.3kg 5L fuel can will give you 5.5kwh and will run near silent for 2 days. If you can spec an AP to within that loading you'd have a win

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Yeah the Efoy units for 110w will run just north of $15k, You can distill your own fuel tho! :P

 

They may have come down in price a bit

 

EFOY 80 Full Cell £2,364.00 inc. VAT

EFOY 140 Full Cell £3,660.00 inc. VAT

 

http://www.fuelcellsystems.co.uk/shop/SFC_Fuel_Cells.html

 

The down side being there will be alcohol on the boat ......  second thoughts maybe a really good self steer system is required :wtf:

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Those ones are too small honestly, the 210 would be the one you want and it's $12k NZ + GST + shipping on that site and EFoy are protective of their dealer networks, I'm not sure any EFoy dealer would ship one outside of their country

 

I wouldn't drink it either! :P

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We would never even remotely class ourselves as anything other than cruisers, but constantly using our AP, according to the averaging current transformer we averaged 5.8 amps between Tauranga and Fiji this year. If that 105w fuel cell is feeding a modest sized battery it would very comfortably manage to average 6 amps. a 72w would be right at its limit. In fact, a 105w would do everything fairly comfortably other than refrigeration. Only need a start battery and maybe a smallish Lithium "house" battery. 

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